1
|
Sung H, Lloyd TE. Disrupted endoplasmic reticulum-mediated autophagosomal biogenesis in a Drosophila model of C9-ALS-FTD. Autophagy 2024; 20:94-113. [PMID: 37599467 PMCID: PMC10761023 DOI: 10.1080/15548627.2023.2249750] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 08/08/2023] [Accepted: 08/11/2023] [Indexed: 08/22/2023] Open
Abstract
ABBREVIATIONS 3R: UAS construct expressing 3 G4C2 repeats (used as control); 3WJ: three-way junction; 12R: UAS construct expressing leader sequence and 12 G4C2 repeats; 30R: UAS construct expressing 30 G4C2 repeats; 36R: UAS construct expressing 36 G4C2 repeats; 44R: UAS construct expressing leader sequence and 44 G4C2 repeats; ALS: amyotrophic lateral sclerosis; Atg: autophagy related; atl: atlastin; C9-ALS-FTD: ALS or FTD caused by hexanuleotide repeat expansion in C9orf72; ER: endoplasmic reticulum; FTD: frontotemporal dementia; HRE: GGGGCC hexanucleotide repeat expansion; HSP: hereditary spastic paraplegia; Lamp1: lysosomal associated membrane protein 1; MT: microtubule; NMJ: neuromuscular junction; Rab: Ras-associated binding GTPase; RAN: repeat associated non-AUG (RAN) translation; RO-36: UAS construct expression "RNA-only" version of 36 G4C2 repeats in which stop codons in all six reading frames are inserted.; Rtnl1: Reticulon-like 1; SN: segmental nerve; TFEB/Mitf: transcription factor EB/microphthalmia associated transcription factor (Drosophila ortholog of TFEB); TrpA1: transient receptor potential cation channel A1; VAPB: VAMP associated protein B and C; VNC: ventral nerve cord (spinal cord in Drosophila larvae).
Collapse
Affiliation(s)
- Hyun Sung
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
- The Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Thomas E Lloyd
- Department of Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
- The Solomon H. Snyder Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| |
Collapse
|
2
|
Modulation of the Microglial Nogo-A/NgR Signaling Pathway as a Therapeutic Target for Multiple Sclerosis. Cells 2022; 11:cells11233768. [PMID: 36497029 PMCID: PMC9737582 DOI: 10.3390/cells11233768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/23/2022] [Accepted: 11/23/2022] [Indexed: 11/29/2022] Open
Abstract
Current therapeutics targeting chronic phases of multiple sclerosis (MS) are considerably limited in reversing the neural damage resulting from repeated inflammation and demyelination insults in the multi-focal lesions. This inflammation is propagated by the activation of microglia, the endogenous immune cell aiding in the central nervous system homeostasis. Activated microglia may transition into polarized phenotypes; namely, the classically activated proinflammatory phenotype (previously categorized as M1) and the alternatively activated anti-inflammatory phenotype (previously, M2). These transitional microglial phenotypes are dynamic states, existing as a continuum. Shifting microglial polarization to an anti-inflammatory status may be a potential therapeutic strategy that can be harnessed to limit neuroinflammation and further neurodegeneration in MS. Our research has observed that the obstruction of signaling by inhibitory myelin proteins such as myelin-associated inhibitory factor, Nogo-A, with its receptor (NgR), can regulate microglial cell function and activity in pre-clinical animal studies. Our review explores the microglial role and polarization in MS pathology. Additionally, the potential therapeutics of targeting Nogo-A/NgR cellular mechanisms on microglia migration, polarization and phagocytosis for neurorepair in MS and other demyelination diseases will be discussed.
Collapse
|
3
|
Rodriguez CM, Bechek SC, Jones GL, Nakayama L, Akiyama T, Kim G, Solow-Cordero DE, Strittmatter SM, Gitler AD. Targeting RTN4/NoGo-Receptor reduces levels of ALS protein ataxin-2. Cell Rep 2022; 41:111505. [PMID: 36288715 PMCID: PMC9664481 DOI: 10.1016/j.celrep.2022.111505] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 05/30/2022] [Accepted: 09/22/2022] [Indexed: 01/27/2023] Open
Abstract
Gene-based therapeutic strategies to lower ataxin-2 levels are emerging for the neurodegenerative diseases amyotrophic lateral sclerosis (ALS) and spinocerebellar ataxia type 2 (SCA2). Additional strategies to lower levels of ataxin-2 could be beneficial. Here, we perform a genome-wide arrayed small interfering RNA (siRNA) screen in human cells and identify RTN4R, the gene encoding the RTN4/NoGo-Receptor, as a potent modifier of ataxin-2 levels. RTN4R knockdown, or treatment with a peptide inhibitor, is sufficient to lower ataxin-2 protein levels in mouse and human neurons in vitro, and Rtn4r knockout mice have reduced ataxin-2 levels in vivo. We provide evidence that ataxin-2 shares a role with the RTN4/NoGo-Receptor in limiting axonal regeneration. Reduction of either protein increases axonal regrowth following axotomy. These data define the RTN4/NoGo-Receptor as a novel therapeutic target for ALS and SCA2 and implicate the targeting of ataxin-2 as a potential treatment following nerve injury.
Collapse
Affiliation(s)
- Caitlin M Rodriguez
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sophia C Bechek
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Graham L Jones
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Lisa Nakayama
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Tetsuya Akiyama
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Garam Kim
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA; Stanford Neurosciences Interdepartmental Program, Stanford University School of Medicine, Stanford, CA, USA
| | - David E Solow-Cordero
- High-Throughput Bioscience Center, Department of Chemical and Systems Biology, Stanford University, Stanford, CA, USA
| | - Stephen M Strittmatter
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT, USA
| | - Aaron D Gitler
- Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA.
| |
Collapse
|
4
|
The endoplasmic reticulum adopts two distinct tubule forms. Proc Natl Acad Sci U S A 2022; 119:e2117559119. [PMID: 35471903 PMCID: PMC9170160 DOI: 10.1073/pnas.2117559119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The endoplasmic reticulum (ER) is one of the most structurally visible and functionally important organelles in the cell. Utilizing superresolution microscopy, we here unveil that in the mammalian cell, the peripheral ER adopts two distinct, well-defined tubule forms of contrasting structures, molecular signatures, and functions, with one of the two curiously being ribbon-like, ultranarrow sheets of fixed widths. With fast multicolor microscopy, we further show how the two tubule forms dynamically interconvert while differentially accommodating proteins in the living cell. The endoplasmic reticulum (ER) is a versatile organelle with diverse functions. Through superresolution microscopy, we show that the peripheral ER in the mammalian cell adopts two distinct forms of tubules. Whereas an ultrathin form, R1, is consistently covered by ER-membrane curvature-promoting proteins, for example, Rtn4 in the native cell, in the second form, R2, Rtn4 and analogs are arranged into two parallel lines at a conserved separation of ∼105 nm over long ranges. The two tubule forms together account for ∼90% of the total tubule length in the cell, with either one being dominant in different cell types. The R1–R2 dichotomy and the final tubule geometry are both coregulated by Rtn4 (and analogs) and the ER sheet–maintaining protein Climp63, which, respectively, define the edge curvature and lumen height of the R2 tubules to generate a ribbon-like structure of well-defined width. Accordingly, the R2 tubule width correlates positively with the Climp63 intraluminal size. The R1 and R2 tubules undergo active remodeling at the second/subsecond timescales as they differently accommodate proteins, with the former effectively excluding ER-luminal proteins and ER-membrane proteins with large intraluminal domains. We thus uncover a dynamic structural dichotomy for ER tubules with intriguing functional implications.
Collapse
|
5
|
Intertwined and Finely Balanced: Endoplasmic Reticulum Morphology, Dynamics, Function, and Diseases. Cells 2021; 10:cells10092341. [PMID: 34571990 PMCID: PMC8472773 DOI: 10.3390/cells10092341] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 09/02/2021] [Accepted: 09/04/2021] [Indexed: 02/07/2023] Open
Abstract
The endoplasmic reticulum (ER) is an organelle that is responsible for many essential subcellular processes. Interconnected narrow tubules at the periphery and thicker sheet-like regions in the perinuclear region are linked to the nuclear envelope. It is becoming apparent that the complex morphology and dynamics of the ER are linked to its function. Mutations in the proteins involved in regulating ER structure and movement are implicated in many diseases including neurodegenerative diseases such as Alzheimer’s, Parkinson’s, and amyotrophic lateral sclerosis (ALS). The ER is also hijacked by pathogens to promote their replication. Bacteria such as Legionella pneumophila and Chlamydia trachomatis, as well as the Zika virus, bind to ER morphology and dynamics-regulating proteins to exploit the functions of the ER to their advantage. This review covers our understanding of ER morphology, including the functional subdomains and membrane contact sites that the organelle forms. We also focus on ER dynamics and the current efforts to quantify ER motion and discuss the diseases related to ER morphology and dynamics.
Collapse
|
6
|
Parakh S, Perri ER, Vidal M, Sultana J, Shadfar S, Mehta P, Konopka A, Thomas CJ, Spencer DM, Atkin JD. Protein disulphide isomerase (PDI) is protective against amyotrophic lateral sclerosis (ALS)-related mutant Fused in Sarcoma (FUS) in in vitro models. Sci Rep 2021; 11:17557. [PMID: 34475430 PMCID: PMC8413276 DOI: 10.1038/s41598-021-96181-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 07/26/2021] [Indexed: 12/04/2022] Open
Abstract
Mutations in Fused in Sarcoma (FUS) are present in familial and sporadic cases of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). FUS is localised in the nucleus where it has important functions in DNA repair. However, in ALS/FTD, mutant FUS mislocalises from the nucleus to the cytoplasm where it forms inclusions, a key pathological hallmark of neurodegeneration. Mutant FUS also inhibits protein import into the nucleus, resulting in defects in nucleocytoplasmic transport. Fragmentation of the neuronal Golgi apparatus, induction of endoplasmic reticulum (ER) stress, and inhibition of ER-Golgi trafficking are also associated with mutant FUS misfolding in ALS. Protein disulphide isomerase (PDI) is an ER chaperone previously shown to be protective against misfolding associated with mutant superoxide dismutase 1 (SOD1) and TAR DNA-binding protein-43 (TDP-43) in cellular and zebrafish models. However, a protective role against mutant FUS in ALS has not been previously described. In this study, we demonstrate that PDI is protective against mutant FUS. In neuronal cell line and primary cultures, PDI restores defects in nuclear import, prevents the formation of mutant FUS inclusions, inhibits Golgi fragmentation, ER stress, ER-Golgi transport defects, and apoptosis. These findings imply that PDI is a new therapeutic target in FUS-associated ALS.
Collapse
Affiliation(s)
- S Parakh
- Macquarie Centre for MND Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia.,Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - E R Perri
- Macquarie Centre for MND Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia.,Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - M Vidal
- Macquarie Centre for MND Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - J Sultana
- Macquarie Centre for MND Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia.,Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - S Shadfar
- Macquarie Centre for MND Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - P Mehta
- Macquarie Centre for MND Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - A Konopka
- Macquarie Centre for MND Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - C J Thomas
- Department of Physiology, Anatomy and Microbiology, La Trobe University, Melbourne, VIC, 3086, Australia
| | - D M Spencer
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - J D Atkin
- Macquarie Centre for MND Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia. .,Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia.
| |
Collapse
|
7
|
The Implication of Reticulons (RTNs) in Neurodegenerative Diseases: From Molecular Mechanisms to Potential Diagnostic and Therapeutic Approaches. Int J Mol Sci 2021; 22:ijms22094630. [PMID: 33924890 PMCID: PMC8125174 DOI: 10.3390/ijms22094630] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/21/2021] [Accepted: 04/23/2021] [Indexed: 02/07/2023] Open
Abstract
Reticulons (RTNs) are crucial regulatory factors in the central nervous system (CNS) as well as immune system and play pleiotropic functions. In CNS, RTNs are transmembrane proteins mediating neuroanatomical plasticity and functional recovery after central nervous system injury or diseases. Moreover, RTNs, particularly RTN4 and RTN3, are involved in neurodegeneration and neuroinflammation processes. The crucial role of RTNs in the development of several neurodegenerative diseases, including Alzheimer's disease (AD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), or other neurological conditions such as brain injury or spinal cord injury, has attracted scientific interest. Reticulons, particularly RTN-4A (Nogo-A), could provide both an understanding of early pathogenesis of neurodegenerative disorders and be potential therapeutic targets which may offer effective treatment or inhibit disease progression. This review focuses on the molecular mechanisms and functions of RTNs and their potential usefulness in clinical practice as a diagnostic tool or therapeutic strategy.
Collapse
|
8
|
Parakh S, Atkin JD. The Mitochondrial-associated ER membrane (MAM) compartment and its dysregulation in Amyotrophic Lateral Sclerosis (ALS). Semin Cell Dev Biol 2021; 112:105-113. [PMID: 33707063 DOI: 10.1016/j.semcdb.2021.02.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 02/04/2021] [Accepted: 02/05/2021] [Indexed: 12/11/2022]
Abstract
The endoplasmic reticulum (ER) and mitochondria connect at multiple contact sites to form a unique cellular compartment, termed the 'mitochondria-associated ER membranes' (MAMs). MAMs are hubs for signalling pathways that regulate cellular homeostasis and survival, metabolism, and sensitivity to apoptosis. MAMs are therefore involved in vital cellular functions, but they are dysregulated in several human diseases. Whilst MAM dysfunction is increasingly implicated in the pathogenesis of neurodegenerative diseases, its role in amyotrophic lateral sclerosis (ALS) is poorly understood. However, in ALS both ER and mitochondrial dysfunction are well documented pathophysiological events. Moreover, alterations to lipid metabolism in neurons regulate processes linked to neurodegenerative diseases, and a link between dysfunction of lipid metabolism and ALS has also been proposed. In this review we discuss the structural and functional relevance of MAMs in ALS and how targeting MAM could be therapeutically beneficial in this disorder.
Collapse
Affiliation(s)
- Sonam Parakh
- Macquarie University Centre for MND Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia
| | - Julie D Atkin
- Macquarie University Centre for MND Research, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW, 2109, Australia; Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Victoria, 3065, Australia.
| |
Collapse
|
9
|
Abstract
Nogo-A is considered one of the most important inhibitors of myelin-associated axonal regeneration in the central nervous system. It is mainly expressed by oligodendrocytes. Although previous studies have found regulatory roles for Nogo-A in neurite outgrowth inhibition, neuronal homeostasis, precursor migration, plasticity, and neurodegeneration, its functions in the process of oxidative injury are largely uncharacterized. In this study, oligodendrocytes were extracted from the cerebral cortex of newborn Sprague-Dawley rats. We used hydrogen peroxide (H2O2) to induce an in vitro oligodendrocyte oxidative damage model and found that endogenously expressed Nogo-A is significantly upregulated in oligodendrocytes. After recombinant virus Ad-ZsGreen-rat Nogo-A infection of oligodendrocytes, Nogo-A expression was increased, and the infected oligodendrocytes were more susceptible to acute oxidative insults and exhibited a markedly elevated rate of cell death. Furthermore, knockdown of Nogo-A expression in oligodendrocytes by Ad-ZsGreen-shRNA-Nogo-A almost completely protected against oxidative stress induced by exogenous H2O2. Intervention with a Nogo-66 antibody, a LINGO1 blocker, or Y27632, an inhibitor in the Nogo-66-NgR/p75/LINGO-1-RhoA-ROCK pathway, did not affect the death of oligodendrocytes. Ad-ZsGreen-shRNA-Nogo-A also increased the levels of phosphorylated extracellular signal-regulated kinase 1/2 and inhibited BCL2 expression in oligodendrocytes. In conclusion, Nogo-A aggravated reactive oxygen species damage in oligodendrocytes, and phosphorylated extracellular signal-regulated kinase 1/2 and BCL2 might be involved in this process. This study was approved by the Ethics Committee of Peking University People’s Hospital, China (approval No. 2018PHC081) on December 18, 2018.
Collapse
Affiliation(s)
- Yang-Yang Wang
- Department of Neurology, Peking University People's Hospital, Beijing, China
| | - Na Han
- Department of Neurology, Peking University People's Hospital, Beijing, China
| | - Dao-Jun Hong
- Department of Neurology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi Province, China
| | - Jun Zhang
- Department of Neurology, Peking University People's Hospital, Beijing, China
| |
Collapse
|
10
|
Mookherjee D, Majumder P, Mukherjee R, Chatterjee D, Kaul Z, Das S, Sougrat R, Chakrabarti S, Chakrabarti O. Cytosolic aggregates in presence of non‐translocated proteins perturb endoplasmic reticulum structure and dynamics. Traffic 2019; 20:943-960. [DOI: 10.1111/tra.12694] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 08/21/2019] [Accepted: 08/29/2019] [Indexed: 12/13/2022]
Affiliation(s)
- Debdatto Mookherjee
- Biophysics & Structural Genomics DivisionSaha Institute of Nuclear Physics Kolkata India
| | - Priyanka Majumder
- Biophysics & Structural Genomics DivisionSaha Institute of Nuclear Physics Kolkata India
- Department of Life Sciences, School of Natural SciencesShiv Nadar University Dadri UP India
| | - Rukmini Mukherjee
- Biophysics & Structural Genomics DivisionSaha Institute of Nuclear Physics Kolkata India
- Buchmann Institute for Molecular Life Sciences Frankfurt Am Main Germany
| | - Debmita Chatterjee
- Biophysics & Structural Genomics DivisionSaha Institute of Nuclear Physics Kolkata India
| | - Zenia Kaul
- Biophysics & Structural Genomics DivisionSaha Institute of Nuclear Physics Kolkata India
- Department of Microbiology, Immunology, and Cancer BiologyUniversity of Virginia School of Medicine Charlottesville Virginia
| | - Subhrangshu Das
- Structural Biology and Bioinformatics DivisionCSIR‐Indian Institute of Chemical Biology Kolkata India
| | - Rachid Sougrat
- Imaging and Characterization Lab4700 King Abdullah University of Science and Technology Thuwal Kingdom of Saudi Arabia
| | - Saikat Chakrabarti
- Structural Biology and Bioinformatics DivisionCSIR‐Indian Institute of Chemical Biology Kolkata India
| | - Oishee Chakrabarti
- Biophysics & Structural Genomics DivisionSaha Institute of Nuclear Physics Kolkata India
- Homi Bhabha National Institute Mumbai India
| |
Collapse
|
11
|
Farías GG, Fréal A, Tortosa E, Stucchi R, Pan X, Portegies S, Will L, Altelaar M, Hoogenraad CC. Feedback-Driven Mechanisms between Microtubules and the Endoplasmic Reticulum Instruct Neuronal Polarity. Neuron 2019; 102:184-201.e8. [PMID: 30772082 DOI: 10.1016/j.neuron.2019.01.030] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 11/29/2018] [Accepted: 01/15/2019] [Indexed: 12/20/2022]
Abstract
Establishment of neuronal polarity depends on local microtubule (MT) reorganization. The endoplasmic reticulum (ER) consists of cisternae and tubules and, like MTs, forms an extensive network throughout the entire cell. How the two networks interact and control neuronal development is an outstanding question. Here we show that the interplay between MTs and the ER is essential for neuronal polarity. ER tubules localize within the axon, whereas ER cisternae are retained in the somatodendritic domain. MTs are essential for axonal ER tubule stabilization, and, reciprocally, the ER is required for stabilizing and organizing axonal MTs. Recruitment of ER tubules into one minor neurite initiates axon formation, whereas ER retention in the perinuclear area or disruption of ER tubules prevent neuronal polarization. The ER-shaping protein P180, present in axonal ER tubules, controls axon specification by regulating local MT remodeling. We propose a model in which feedback-driven regulation between the ER and MTs instructs neuronal polarity.
Collapse
Affiliation(s)
- Ginny G Farías
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, the Netherlands.
| | - Amélie Fréal
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, the Netherlands
| | - Elena Tortosa
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, the Netherlands
| | - Riccardo Stucchi
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, the Netherlands; Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Xingxiu Pan
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, the Netherlands
| | - Sybren Portegies
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, the Netherlands
| | - Lena Will
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, the Netherlands
| | - Maarten Altelaar
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CH Utrecht, the Netherlands
| | - Casper C Hoogenraad
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Utrecht 3584 CH, the Netherlands.
| |
Collapse
|
12
|
Yanagi KS, Wu Z, Amaya J, Chapkis N, Duffy AM, Hajdarovic KH, Held A, Mathur AD, Russo K, Ryan VH, Steinert BL, Whitt JP, Fallon JR, Fawzi NL, Lipscombe D, Reenan RA, Wharton KA, Hart AC. Meta-analysis of Genetic Modifiers Reveals Candidate Dysregulated Pathways in Amyotrophic Lateral Sclerosis. Neuroscience 2019; 396:A3-A20. [PMID: 30594291 PMCID: PMC6549511 DOI: 10.1016/j.neuroscience.2018.10.033] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 10/14/2018] [Accepted: 10/16/2018] [Indexed: 12/11/2022]
Abstract
Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease that has significant overlap with frontotemporal dementia (FTD). Mutations in specific genes have been identified that can cause and/or predispose patients to ALS. However, the clinical variability seen in ALS patients suggests that additional genes impact pathology, susceptibility, severity, and/or progression of the disease. To identify molecular pathways involved in ALS, we undertook a meta-analysis of published genetic modifiers both in patients and in model organisms, and undertook bioinformatic pathway analysis. From 72 published studies, we generated a list of 946 genes whose perturbation (1) impacted ALS in patient populations, (2) altered defects in laboratory models, or (3) modified defects caused by ALS gene ortholog loss of function. Herein, these are all called modifier genes. We found 727 modifier genes that encode proteins with human orthologs. Of these, 43 modifier genes were identified as modifiers of more than one ALS gene/model, consistent with the hypothesis that shared genes and pathways may underlie ALS. Further, we used a gene ontology-based bioinformatic analysis to identify pathways and associated genes that may be important in ALS. To our knowledge this is the first comprehensive survey of ALS modifier genes. This work suggests that shared molecular mechanisms may underlie pathology caused by different ALS disease genes. Surprisingly, few ALS modifier genes have been tested in more than one disease model. Understanding genes that modify ALS-associated defects will help to elucidate the molecular pathways that underlie ALS and provide additional targets for therapeutic intervention.
Collapse
Affiliation(s)
- Katherine S Yanagi
- Neuroscience Graduate Program, Brown University, Providence, Rhode Island 02912, United States; Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912, United States.
| | - Zhijin Wu
- Department of Biostatistics, Brown University, Providence, Rhode Island 02912, United States.
| | - Joshua Amaya
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, Rhode Island 02912, United States; Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912, United States.
| | - Natalie Chapkis
- Department of Neuroscience, Brown University, Providence, Rhode Island 02912, United States; Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912, United States.
| | - Amanda M Duffy
- Neuroscience Graduate Program, Brown University, Providence, Rhode Island 02912, United States; Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912, United States.
| | - Kaitlyn H Hajdarovic
- Neuroscience Graduate Program, Brown University, Providence, Rhode Island 02912, United States; Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912, United States.
| | - Aaron Held
- Molecular Biology, Cell Biology, and Biochemistry Graduate Program, Brown University, Providence, Rhode Island 02912, United States; Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912, United States.
| | - Arjun D Mathur
- Molecular Biology, Cell Biology, and Biochemistry Graduate Program, Brown University, Providence, Rhode Island 02912, United States; Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912, United States.
| | - Kathryn Russo
- Neuroscience Graduate Program, Brown University, Providence, Rhode Island 02912, United States; Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912, United States.
| | - Veronica H Ryan
- Neuroscience Graduate Program, Brown University, Providence, Rhode Island 02912, United States; Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912, United States.
| | - Beatrice L Steinert
- Molecular Biology, Cell Biology, and Biochemistry Department, Brown University, Providence, Rhode Island 02912, United States; Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912, United States.
| | - Joshua P Whitt
- Department of Neuroscience, Brown University, Providence, Rhode Island 02912, United States; Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912, United States.
| | - Justin R Fallon
- Department of Neuroscience, Brown University, Providence, Rhode Island 02912, United States; Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912, United States.
| | - Nicolas L Fawzi
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, Rhode Island 02912, United States; Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912, United States.
| | - Diane Lipscombe
- Department of Neuroscience, Brown University, Providence, Rhode Island 02912, United States; Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912, United States.
| | - Robert A Reenan
- Molecular Biology, Cell Biology, and Biochemistry Department, Brown University, Providence, Rhode Island 02912, United States; Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912, United States.
| | - Kristi A Wharton
- Molecular Biology, Cell Biology, and Biochemistry Department, Brown University, Providence, Rhode Island 02912, United States; Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912, United States.
| | - Anne C Hart
- Department of Neuroscience, Brown University, Providence, Rhode Island 02912, United States; Robert J. and Nancy D. Carney Institute for Brain Science, Brown University, Providence, Rhode Island 02912, United States.
| |
Collapse
|
13
|
Abstract
The endoplasmic reticulum (ER) is a morphologically dynamic organelle containing different membrane subdomains with distinct cellular functions. Numerous observations have revealed that ER stress response induced by disturbed ER homeostasis is linked to various neurological/neurodegenerative disorders. In contrast, recent findings unveil that ER structural derangements are linked to the progression of several neurological diseases. The derangements involve two distinct, and likely opposing pathways. One is dysfunction of ER dynamics machinery, leading to disruption of ER network organization. Another one is facilitation of pre-existing machinery, leading to generation of markedly-ordered de novo membranous structure. Restoring the ER network can be the effective way toward the cure of ER-deranged neurological disorders.
Collapse
Affiliation(s)
- Tomoyuki Yamanaka
- Laboratory of Structural Neuropathology, Graduate School of Brain Science, Doshisha University, Kyoto, Japan
| | - Nobuyuki Nukina
- Laboratory of Structural Neuropathology, Graduate School of Brain Science, Doshisha University, Kyoto, Japan
| |
Collapse
|
14
|
Quiles JM, Narasimhan M, Mosbruger T, Shanmugam G, Crossman D, Rajasekaran NS. Identification of transcriptome signature for myocardial reductive stress. Redox Biol 2017; 13:568-580. [PMID: 28768233 PMCID: PMC5536881 DOI: 10.1016/j.redox.2017.07.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Revised: 07/20/2017] [Accepted: 07/20/2017] [Indexed: 12/20/2022] Open
Abstract
The nuclear factor erythroid 2 like 2 (Nfe2l2/Nrf2) is a master regulator of antioxidant gene transcription. We recently identified that constitutive activation of Nrf2 (CaNrf2) caused reductive stress (RS) in the myocardium. Here we investigate how chronic Nrf2 activation alters myocardial mRNA transcriptome in the hearts of CaNrf2 transgenic (TG-low and TG-high) mice using an unbiased integrated systems approach and next generation RNA sequencing followed by qRT-PCR methods. A total of 246 and 1031 differentially expressed genes (DEGs) were identified in the heart of TGL and TGH in relation to NTG littermates at ~ 6 months of age. Notably, the expression and validation of the transcripts were gene-dosage dependent and statistically significant. Ingenuity Pathway Analysis identified enriched biological processes and canonical pathways associated with myocardial RS in the CaNrf2-TG mice. In addition, an overrepresentation of xenobiotic metabolic signaling, glutathione-mediated detoxification, unfolded protein response, and protein ubiquitination was observed. Other, non-canonical signaling pathways identified include: eNOS, integrin-linked kinase, glucocorticoid receptor, PI3/AKT, actin cytoskeleton, cardiac hypertrophy, and the endoplasmic reticulum stress response. In conclusion, this mRNA profiling identified a "biosignature" for pro-reductive (TGL) and reductive stress (TGH) that can predict the onset, rate of progression, and clinical outcome of Nrf2-dependent myocardial complications. We anticipate that this global sequencing analysis will illuminate the undesirable effect of chronic Nrf2 signaling leading to RS-mediated pathogenesis besides providing important guidance for the application of Nrf2 activation-based cytoprotective strategies.
Collapse
Affiliation(s)
- Justin M Quiles
- Cardiac Aging & Redox Signaling Laboratory, Division of Molecular & Cellular Pathology, Department of Pathology, The University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Madhusudhanan Narasimhan
- Department of Pharmacology and Neuroscience, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Timothy Mosbruger
- Division of Cardiovascular Medicine, Department of Medicine, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
| | - Gobinath Shanmugam
- Cardiac Aging & Redox Signaling Laboratory, Division of Molecular & Cellular Pathology, Department of Pathology, The University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - David Crossman
- Heflin Center for Genomic Sciences, The University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Namakkal S Rajasekaran
- Cardiac Aging & Redox Signaling Laboratory, Division of Molecular & Cellular Pathology, Department of Pathology, The University of Alabama at Birmingham, Birmingham, AL 35294, USA; Division of Cardiovascular Medicine, Department of Medicine, University of Utah School of Medicine, Salt Lake City, UT 84132, USA; Center for Free Radical Biology, The University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| |
Collapse
|
15
|
Extended Synaptotagmin Localizes to Presynaptic ER and Promotes Neurotransmission and Synaptic Growth in Drosophila. Genetics 2017; 207:993-1006. [PMID: 28882990 DOI: 10.1534/genetics.117.300261] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 09/01/2017] [Indexed: 01/08/2023] Open
Abstract
The endoplasmic reticulum (ER) is an extensive organelle in neurons with important roles at synapses including the regulation of cytosolic Ca2+, neurotransmission, lipid metabolism, and membrane trafficking. Despite intriguing evidence for these crucial functions, how the presynaptic ER influences synaptic physiology remains enigmatic. To gain insight into this question, we have generated and characterized mutations in the single extended synaptotagmin (Esyt) ortholog in Drosophila melanogaster Esyts are evolutionarily conserved ER proteins with Ca2+-sensing domains that have recently been shown to orchestrate membrane tethering and lipid exchange between the ER and plasma membrane. We first demonstrate that Esyt localizes to presynaptic ER structures at the neuromuscular junction. Next, we show that synaptic growth, structure, and homeostatic plasticity are surprisingly unperturbed at synapses lacking Esyt expression. However, neurotransmission is reduced in Esyt mutants, consistent with a presynaptic role in promoting neurotransmitter release. Finally, neuronal overexpression of Esyt enhances synaptic growth and the sustainment of the vesicle pool during intense activity, suggesting that increased Esyt levels may modulate the membrane trafficking and/or resting Ca2+ pathways that control synapse extension. Thus, we identify Esyt as a presynaptic ER protein that can promote neurotransmission and synaptic growth, revealing the first in vivo neuronal functions of this conserved gene family.
Collapse
|
16
|
Lammert DB, Middleton FA, Pan J, Olson EC, Howell BW. The de novo autism spectrum disorder RELN R2290C mutation reduces Reelin secretion and increases protein disulfide isomerase expression. J Neurochem 2017; 142:89-102. [PMID: 28419454 DOI: 10.1111/jnc.14045] [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: 12/16/2016] [Revised: 03/22/2017] [Accepted: 04/05/2017] [Indexed: 12/11/2022]
Abstract
Despite the recent identification of over 40 missense heterozygous Reelin gene (RELN) mutations in autism spectrum disorder (ASD), none of these has been functionally characterized. Reelin is an integral signaling ligand for proper brain development and post-natal synapse function - properties likely disrupted in ASD patients. We find that the R2290C mutation, which arose de novo in an affected ASD proband, and other analogous mutations in arginine-amino acid-arginine domains reduce protein secretion. Closer analysis of RELN R2290C heterozygous neurospheres reveals up-regulation of Protein Disulfide Isomerase A1, best known as an endoplasmic reticulum-chaperone protein, which has been linked to neuronal pathology. This effect is recapitulated in a heterozygous RELN mouse mutant that is characterized by defective Reelin secretion. These findings suggest that both a deficiency in Reelin signaling and pathologic impairment of Reelin secretion may contribute to ASD risk.
Collapse
Affiliation(s)
- Dawn B Lammert
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Frank A Middleton
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Jen Pan
- The Broad Institute, Stanley Center Neurobiology, Cambridge, Massachusetts, USA
| | - Eric C Olson
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Brian W Howell
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, New York, USA
| |
Collapse
|
17
|
Boghdadi AG, Teo L, Bourne JA. The Involvement of the Myelin-Associated Inhibitors and Their Receptors in CNS Plasticity and Injury. Mol Neurobiol 2017; 55:1831-1846. [PMID: 28229330 DOI: 10.1007/s12035-017-0433-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 01/31/2017] [Indexed: 12/21/2022]
Abstract
The limited capacity for the central nervous system (CNS) to repair itself was first described over 100 years ago by Spanish neuroscientist Ramon Y. Cajal. However, the exact mechanisms underlying this failure in neuronal regeneration remain unclear and, as such, no effective therapeutics yet exist. Numerous studies have attempted to elucidate the biochemical and molecular mechanisms that inhibit neuronal repair with increasing evidence suggesting that several inhibitory factors and repulsive guidance cues active during development actually persist into adulthood and may be contributing to the inhibition of repair. For example, in the injured adult CNS, there are various inhibitory factors that impede the outgrowth of neurites from damaged neurons. One of the most potent of these neurite outgrowth inhibitors is the group of proteins known as the myelin-associated inhibitors (MAIs), present mainly on the membranes of oligodendroglia. Several studies have shown that interfering with these proteins can have positive outcomes in CNS injury models by promoting neurite outgrowth and improving functional recovery. As such, the MAIs, their receptors, and downstream effectors are valid drug targets for the treatment of CNS injury. This review will discuss the current literature on MAIs in the context of CNS development, plasticity, and injury. Molecules that interfere with the MAIs and their receptors as potential candidates for the treatment of CNS injury will additionally be introduced in the context of preclinical and clinical trials.
Collapse
Affiliation(s)
- Anthony G Boghdadi
- Australian Regenerative Medicine Institute, Monash University, 15 Innovation Walk (Building 75), Clayton, VIC, 3800, Australia
| | - Leon Teo
- Australian Regenerative Medicine Institute, Monash University, 15 Innovation Walk (Building 75), Clayton, VIC, 3800, Australia
| | - James A Bourne
- Australian Regenerative Medicine Institute, Monash University, 15 Innovation Walk (Building 75), Clayton, VIC, 3800, Australia.
| |
Collapse
|
18
|
Valle C, Carrì MT. Cysteine Modifications in the Pathogenesis of ALS. Front Mol Neurosci 2017; 10:5. [PMID: 28167899 PMCID: PMC5253364 DOI: 10.3389/fnmol.2017.00005] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 01/06/2017] [Indexed: 12/13/2022] Open
Abstract
Several proteins are found misfolded and aggregated in sporadic and genetic forms of amyotrophic lateral sclerosis (ALS). These include superoxide dismutase (SOD1), transactive response DNA-binding protein (TDP-43), fused in sarcoma/translocated in liposarcoma protein (FUS/TLS), p62, vasolin-containing protein (VCP), Ubiquilin-2 and dipeptide repeats produced by unconventional RAN-translation of the GGGGCC expansion in C9ORF72. Up to date, functional studies have not yet revealed a common mechanism for the formation of such diverse protein inclusions. Consolidated studies have demonstrated a fundamental role of cysteine residues in the aggregation process of SOD1 and TDP43, but disturbance of protein thiols homeostatic factors such as protein disulfide isomerases (PDI), glutathione, cysteine oxidation or palmitoylation might contribute to a general aberration of cysteine residues proteostasis in ALS. In this article we review the evidence that cysteine modifications may have a central role in many, if not all, forms of this disease.
Collapse
Affiliation(s)
- Cristiana Valle
- Institute for Cell Biology and Neurobiology, CNRRome, Italy
- Fondazione Santa Lucia IRCCSRome, Italy
| | - Maria Teresa Carrì
- Fondazione Santa Lucia IRCCSRome, Italy
- Department of Biology, University of Rome Tor VergataRome, Italy
| |
Collapse
|
19
|
Perri E, Parakh S, Atkin J. Protein Disulphide Isomerases: emerging roles of PDI and ERp57 in the nervous system and as therapeutic targets for ALS. Expert Opin Ther Targets 2016; 21:37-49. [PMID: 27786579 DOI: 10.1080/14728222.2016.1254197] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
INTRODUCTION There is increasing evidence that endoplasmic reticulum (ER) chaperones Protein Disulphide Isomerase (PDI) and ERp57 (endoplasmic reticulum protein 57) are protective against neurodegenerative diseases related to protein misfolding, including Amyotrophic Lateral Sclerosis (ALS). PDI and ERp57 also possess disulphide interchange activity, in which protein disulphide bonds are oxidized, reduced and isomerized, to form their native conformation. Recently, missense and intronic variants of PDI and ERp57 were associated with ALS, implying that PDI proteins are relevant to ALS pathology. Areas covered: Here, we discuss possible implications of the PDI and ERp57 variants, as well as recent studies describing previously unrecognized roles for PDI and ERp57 in the nervous system. Therapeutics based on PDI may therefore be attractive candidates for ALS. However, in addition to its protective functions, aberrant, toxic roles for PDI have recently been described. These functions need to be fully characterized before effective therapeutic strategies can be designed. Expert opinion: These disease-associated variants of PDI and ERp57 provide additional evidence for an important role for PDI proteins in ALS. However, there are many questions remaining unanswered that need to be addressed before the potential of the PDI family in relation to ALS can be fully realized.
Collapse
Affiliation(s)
- Emma Perri
- a Department of Biomedical Sciences, Faculty of Medicine and Health Sciences , Macquarie University , Sydney , Australia
| | - Sonam Parakh
- a Department of Biomedical Sciences, Faculty of Medicine and Health Sciences , Macquarie University , Sydney , Australia
| | - Julie Atkin
- a Department of Biomedical Sciences, Faculty of Medicine and Health Sciences , Macquarie University , Sydney , Australia.,b Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science , La Trobe University , Melbourne , Australia
| |
Collapse
|
20
|
Casas C, Manzano R, Vaz R, Osta R, Brites D. Synaptic Failure: Focus in an Integrative View of ALS. Brain Plast 2016; 1:159-175. [PMID: 29765840 PMCID: PMC5928542 DOI: 10.3233/bpl-140001] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
From early description by Charcot, the classification of the Amyotrophic Lateral Sclerosis (ALS) is evolving from a subtype of Motor Neuron (MN) Disease to be considered rather a multi-systemic, non-cell autonomous and complex neurodegenerative disease. In the last decade, the huge amount of knowledge acquired has shed new insights on the pathological mechanisms underlying ALS from different perspectives. However, a whole vision on the multiple dysfunctional pathways is needed with the inclusion of information often excluded in other published revisions. We propose an integrative view of ALS pathology, although centered on the synaptic failure as a converging and crucial player to the etiology of the disease. Homeostasis of input and output synaptic activity of MNs has been proved to be severely and early disrupted and to definitively contribute to microcircuitry alterations at the spinal cord. Several cells play roles in synaptic communication across the MNs network system such as interneurons, astrocytes, microglia, Schwann and skeletal muscle cells. Microglia are described as highly dynamic surveying cells of the nervous system but also as determinant contributors to the synaptic plasticity linked to neuronal activity. Several signaling axis such as TNFα/TNFR1 and CX3CR1/CX3CL1 that characterize MN-microglia cross talk contribute to synaptic scaling and maintenance, have been found altered in ALS. The presence of dystrophic and atypical microglia in late stages of ALS, with a decline in their dynamic motility and phagocytic ability, together with less synaptic and neuronal contacts disrupts the MN-microglia dialogue, decreases homeostatic regulation of neuronal activity, perturbs “on/off” signals and accelerates disease progression associated to impaired synaptic function and regeneration. Other hotspot in the ALS affected network system is the unstable neuromuscular junction (NMJ) leading to distal axonal degeneration. Reduced neuromuscular spontaneous synaptic activity in ALS mice models was also suggested to account for the selective vulnerability of MNs and decreased regenerative capability. Synaptic destabilization may as well derive from increased release of molecules by muscle cells (e.g. NogoA) and by terminal Schwann cells (e.g. semaphorin 3A) conceivably causing nerve terminal retraction and denervation, as well as inhibition of re-connection to muscle fibers. Indeed, we have overviewed the alterations on the metabolic pathways and self-regenerative capacity presented in skeletal muscle cells that contribute to muscle wasting in ALS. Finally, a detailed footpath of pathologic changes on MNs and associated dysfunctional and synaptic alterations is provided. The oriented motivation in future ALS studies as outlined in the present article will help in fruitful novel achievements on the mechanisms involved and in developing more target-driven therapies that will bring new hope in halting or delaying disease progression in ALS patients.
Collapse
Affiliation(s)
- Caty Casas
- Group of Neuroplasticity and Regeneration, Institut de Neurociències and Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Barcelona, Spain
| | - Raquel Manzano
- Laboratory of Genetic Biochemistry (LAGENBIO-I3A), Aragón Institute of Health Sciences, Universidad de Zaragoza, Zaragoza, Spain
| | - Rita Vaz
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa Lisbon, Portugal; Department of Biochemistry and Human Biology, Faculdade de Farmácia, Universidade de Lisboa Lisbon, Portugal
| | - Rosario Osta
- Laboratory of Genetic Biochemistry (LAGENBIO-I3A), Aragón Institute of Health Sciences, Universidad de Zaragoza, Zaragoza, Spain
| | - Dora Brites
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa Lisbon, Portugal; Department of Biochemistry and Human Biology, Faculdade de Farmácia, Universidade de Lisboa Lisbon, Portugal
| |
Collapse
|
21
|
Hatakeyama J, Wald JH, Rafidi H, Cuevas A, Sweeney C, Carraway KL. The ER structural protein Rtn4A stabilizes and enhances signaling through the receptor tyrosine kinase ErbB3. Sci Signal 2016; 9:ra65. [PMID: 27353365 DOI: 10.1126/scisignal.aaf1604] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
ErbB3 and ErbB4 are receptor tyrosine kinases that are activated by the neuregulin (NRG) family of growth factors. These receptors govern various developmental processes, and their dysregulation contributes to several human disease states. The abundance of ErbB3 and ErbB4, and thus signaling through these receptors, is limited by the E3 ubiquitin ligase Nrdp1, which targets ErbB3 and ErbB4 for degradation. Reticulons are proteins that influence the morphology of the endoplasmic reticulum (ER) by promoting the formation of tubules, a response of cells to some stressors. We found that the ER structural protein reticulon 4A (Rtn4A, also known as Nogo-A) increased ErbB3 abundance and proliferative signaling by suppressing Nrdp1 function. Rtn4A interacted with Nrdp1 and stabilized ErbB3 in an Nrdp1-dependent manner. Rtn4A overexpression induced the redistribution of Nrdp1 from a cytosolic or perinuclear localization to ER tubules. Rtn4A knockdown in human breast tumor cells decreased ErbB3 abundance, NRG-stimulated signaling, and cellular proliferation and migration. Because proteins destined for the plasma membrane are primarily synthesized in the sheet portions of the ER, our observations suggest that Rtn4A counteracts the Nrdp1-mediated degradation of ErbB3 by sequestering the ubiquitin ligase into ER tubules. The involvement of a reticulon suggests a molecular link between ER structure and the sensitivity of cells to receptor tyrosine kinase-mediated survival signals at the cell surface.
Collapse
Affiliation(s)
- Jason Hatakeyama
- Department of Biochemistry and Molecular Medicine, and UC Davis Comprehensive Cancer Center, UC Davis School of Medicine, Sacramento, CA 95817, USA
| | - Jessica H Wald
- Department of Biochemistry and Molecular Medicine, and UC Davis Comprehensive Cancer Center, UC Davis School of Medicine, Sacramento, CA 95817, USA
| | - Hanine Rafidi
- Department of Biochemistry and Molecular Medicine, and UC Davis Comprehensive Cancer Center, UC Davis School of Medicine, Sacramento, CA 95817, USA
| | - Antonio Cuevas
- Department of Biochemistry and Molecular Medicine, and UC Davis Comprehensive Cancer Center, UC Davis School of Medicine, Sacramento, CA 95817, USA
| | - Colleen Sweeney
- Department of Biochemistry and Molecular Medicine, and UC Davis Comprehensive Cancer Center, UC Davis School of Medicine, Sacramento, CA 95817, USA
| | - Kermit L Carraway
- Department of Biochemistry and Molecular Medicine, and UC Davis Comprehensive Cancer Center, UC Davis School of Medicine, Sacramento, CA 95817, USA.
| |
Collapse
|
22
|
Eggert E, Obata T, Gerstenberger A, Gier K, Brandt T, Fernie AR, Schulze W, Kühn C. A sucrose transporter-interacting protein disulphide isomerase affects redox homeostasis and links sucrose partitioning with abiotic stress tolerance. PLANT, CELL & ENVIRONMENT 2016; 39:1366-1380. [PMID: 26670204 DOI: 10.1111/pce.12694] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 12/08/2015] [Accepted: 12/08/2015] [Indexed: 06/05/2023]
Abstract
Sucrose accumulation in leaves in response to various abiotic stresses suggests a specific role of this disaccharide for stress tolerance and adaptation. The high-affinity transporter StSUT1 undergoes substrate-induced endocytosis presenting the question as to whether altered sucrose accumulation in leaves in response to stresses is also related to enhanced endocytosis or altered activity of the sucrose transporter. StSUT1 is known to interact with several stress-inducible proteins; here we investigated whether one of the interacting candidates, StPDI1, affects its subcellular localization in response to stress: StPDI1 expression is induced by ER-stress and salt. Both proteins, StSUT1 and StPDI1, were found in the detergent resistant membrane (DRM) fraction, and this might affect internalization. Knockdown of StPDI1 expression severely affects abiotic stress tolerance of transgenic potato plants. Analysis of these plants does not reveal modified subcellular localization or endocytosis of StSUT1, but rather a disturbed redox homeostasis, reduced detoxification of reactive oxygen species and effects on primary metabolism. Parallel observations with other StSUT1-interacting proteins are discussed. The redox status in leaves seems to be linked to the sugar status in response to various stress stimuli and to play a role in stress tolerance.
Collapse
Affiliation(s)
- Erik Eggert
- Humboldt University, Institute of Biology, Department of Plant Physiology, Philippstr. 13, Building 12, 10115, Berlin, Germany
| | - Toshihiro Obata
- MPI Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Anne Gerstenberger
- Humboldt University, Institute of Biology, Department of Plant Physiology, Philippstr. 13, Building 12, 10115, Berlin, Germany
| | - Konstanze Gier
- Humboldt University, Institute of Biology, Department of Plant Physiology, Philippstr. 13, Building 12, 10115, Berlin, Germany
| | - Tobias Brandt
- Humboldt University, Institute of Biology, Department of Plant Physiology, Philippstr. 13, Building 12, 10115, Berlin, Germany
| | - Alisdair R Fernie
- MPI Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Waltraud Schulze
- MPI Molecular Plant Physiology, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
- University Hohenheim, Department of Plant Systems Biology, 70593, Stuttgart, Germany
| | - Christina Kühn
- Humboldt University, Institute of Biology, Department of Plant Physiology, Philippstr. 13, Building 12, 10115, Berlin, Germany
| |
Collapse
|
23
|
Protein folding alterations in amyotrophic lateral sclerosis. Brain Res 2016; 1648:633-649. [PMID: 27064076 DOI: 10.1016/j.brainres.2016.04.010] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 04/04/2016] [Accepted: 04/05/2016] [Indexed: 02/07/2023]
Abstract
Protein misfolding leads to the formation of aggregated proteins and protein inclusions, which are associated with synaptic loss and neuronal death in neurodegenerative diseases. Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that targets motor neurons in the brain, brainstem and spinal cord. Several proteins misfold and are associated either genetically or pathologically in ALS, including superoxide dismutase 1 (SOD1), Tar DNA binding protein-43 (TDP-43), Ubiquilin-2, p62, VCP, and dipeptide repeat proteins produced by unconventional repeat associated non-ATG translation of the repeat expansion in C9ORF72. Chaperone proteins, including heat shock proteins (Hsp׳s) and the protein disulphide isomerase (PDI) family, assist in protein folding and therefore can prevent protein misfolding, and have been implicated as being protective in ALS. In this review we provide an overview of the current literature regarding the molecular mechanisms of protein misfolding and aggregation in ALS, and the role of chaperones as potential targets for therapeutic intervention. This article is part of a Special Issue entitled SI:ER stress.
Collapse
|
24
|
Perri ER, Thomas CJ, Parakh S, Spencer DM, Atkin JD. The Unfolded Protein Response and the Role of Protein Disulfide Isomerase in Neurodegeneration. Front Cell Dev Biol 2016; 3:80. [PMID: 26779479 PMCID: PMC4705227 DOI: 10.3389/fcell.2015.00080] [Citation(s) in RCA: 87] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 12/03/2015] [Indexed: 12/11/2022] Open
Abstract
The maintenance and regulation of proteostasis is a critical function for post-mitotic neurons and its dysregulation is increasingly implicated in neurodegenerative diseases. Despite having different clinical manifestations, these disorders share similar pathology; an accumulation of misfolded proteins in neurons and subsequent disruption to cellular proteostasis. The endoplasmic reticulum (ER) is an important component of proteostasis, and when the accumulation of misfolded proteins occurs within the ER, this disturbs ER homeostasis, giving rise to ER stress. This triggers the unfolded protein response (UPR), distinct signaling pathways that whilst initially protective, are pro-apoptotic if ER stress is prolonged. ER stress is increasingly implicated in neurodegenerative diseases, and emerging evidence highlights the complexity of the UPR in these disorders, with both protective and detrimental components being described. Protein Disulfide Isomerase (PDI) is an ER chaperone induced during ER stress that is responsible for the formation of disulfide bonds in proteins. Whilst initially considered to be protective, recent studies have revealed unconventional roles for PDI in neurodegenerative diseases, distinct from its normal function in the UPR and the ER, although these mechanisms remain poorly defined. However, specific aspects of PDI function may offer the potential to be exploited therapeutically in the future. This review will focus on the evidence linking ER stress and the UPR to neurodegenerative diseases, with particular emphasis on the emerging functions ascribed to PDI in these conditions.
Collapse
Affiliation(s)
- Emma R Perri
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University Melbourne, VIC, Australia
| | - Colleen J Thomas
- Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University Melbourne, VIC, Australia
| | - Sonam Parakh
- Department of Biomedical Sciences, Faculty of Medicine and Human Science, Macquarie University Sydney, NSW, Australia
| | - Damian M Spencer
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University Melbourne, VIC, Australia
| | - Julie D Atkin
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe UniversityMelbourne, VIC, Australia; Department of Biomedical Sciences, Faculty of Medicine and Human Science, Macquarie UniversitySydney, NSW, Australia
| |
Collapse
|
25
|
Muresan V, Ladescu Muresan Z. Shared Molecular Mechanisms in Alzheimer's Disease and Amyotrophic Lateral Sclerosis: Neurofilament-Dependent Transport of sAPP, FUS, TDP-43 and SOD1, with Endoplasmic Reticulum-Like Tubules. NEURODEGENER DIS 2015; 16:55-61. [PMID: 26605911 DOI: 10.1159/000439256] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 08/07/2015] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Amyotrophic lateral sclerosis (ALS), a debilitating neurodegenerative disorder of the motor neurons, leads to the disorganization of the neurofilament (NF) cytoskeleton and - ultimately - the deterioration of the neuromuscular junction. Some familial cases of ALS are caused by mutated FUS, TDP-43 or SOD1; it is thought that the mutated proteins inflict pathology either by gain or loss of function. The proper function of the neuromuscular junction requires sAPP, a soluble proteolytic fragment of the amyloid-β precursor protein (APP) - a transmembrane protein implicated in the pathology of Alzheimer's disease (AD). Whether sAPP, FUS, TDP-43 and SOD1 are mechanistically linked in a common pathway deregulated in both AD and ALS is not known. SUMMARY We show that sAPP, TDP-43, FUS and SOD1 are transported to neurite terminals by a mechanism that involves endoplasmic reticulum (ER)-like tubules and requires peripherin NFs. The transport of these proteins, and the translocation of the ER protein reticulon 4 (Rtn4) into neurites was studied in CAD cells, a brainstem-derived neuronal cell line highly relevant to AD and ALS. We show that a significant fraction of sAPP is generated in the soma and accumulates in a juxtanuclear ER subdomain. In neurites, sAPP localizes to Rtn4-positive ER-like tubules that extend from the soma into the growth cone and colocalizes with peripherin NFs. Knocking down peripherin disrupts the NF network and diminishes the accumulation of sAPP, TDP-43, FUS, SOD1 and Rtn4 at terminals. KEY MESSAGES We propose that the impediment of a common, ER-mediated mechanism of transport of sAPP, TDP-43, FUS and SOD1, caused by a disrupted NF network, could be part of the mechanisms leading to AD and ALS.
Collapse
Affiliation(s)
- Virgil Muresan
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, N.J., USA
| | | |
Collapse
|
26
|
Rab1-dependent ER-Golgi transport dysfunction is a common pathogenic mechanism in SOD1, TDP-43 and FUS-associated ALS. Acta Neuropathol 2015; 130:679-97. [PMID: 26298469 DOI: 10.1007/s00401-015-1468-2] [Citation(s) in RCA: 87] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 08/11/2015] [Accepted: 08/12/2015] [Indexed: 12/12/2022]
Abstract
Several diverse proteins are linked genetically/pathologically to neurodegeneration in amyotrophic lateral sclerosis (ALS) including SOD1, TDP-43 and FUS. Using a variety of cellular and biochemical techniques, we demonstrate that ALS-associated mutant TDP-43, FUS and SOD1 inhibit protein transport between the endoplasmic reticulum (ER) and Golgi apparatus in neuronal cells. ER-Golgi transport was also inhibited in embryonic cortical and motor neurons obtained from a widely used animal model (SOD1(G93A) mice), validating this mechanism as an early event in disease. Each protein inhibited transport by distinct mechanisms, but each process was dependent on Rab1. Mutant TDP-43 and mutant FUS both inhibited the incorporation of secretory protein cargo into COPII vesicles as they bud from the ER, and inhibited transport from ER to the ER-Golgi intermediate (ERGIC) compartment. TDP-43 was detected on the cytoplasmic face of the ER membrane, whereas FUS was present within the ER, suggesting that transport is inhibited from the cytoplasm by mutant TDP-43, and from the ER by mutant FUS. In contrast, mutant SOD1 destabilised microtubules and inhibited transport from the ERGIC compartment to Golgi, but not from ER to ERGIC. Rab1 performs multiple roles in ER-Golgi transport, and over-expression of Rab1 restored ER-Golgi transport, and prevented ER stress, mSOD1 inclusion formation and induction of apoptosis, in cells expressing mutant TDP-43, FUS or SOD1. Rab1 also co-localised extensively with mutant TDP-43, FUS and SOD1 in neuronal cells, and Rab1 formed inclusions in motor neurons of spinal cords from sporadic ALS patients, which were positive for ubiquitinated TDP-43, implying that Rab1 is misfolded and dysfunctional in sporadic disease. These results demonstrate that ALS-mutant forms of TDP-43, FUS, and SOD1 all perturb protein transport in the early secretory pathway, between ER and Golgi compartments. These data also imply that restoring Rab1-mediated ER-Golgi transport is a novel therapeutic target in ALS.
Collapse
|
27
|
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
|
28
|
Radoshevich L, Impens F, Ribet D, Quereda JJ, Nam Tham T, Nahori MA, Bierne H, Dussurget O, Pizarro-Cerdá J, Knobeloch KP, Cossart P. ISG15 counteracts Listeria monocytogenes infection. eLife 2015; 4. [PMID: 26259872 PMCID: PMC4530601 DOI: 10.7554/elife.06848] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 07/15/2015] [Indexed: 12/12/2022] Open
Abstract
ISG15 is an interferon-stimulated, linear di-ubiquitin-like protein, with anti-viral activity. The role of ISG15 during bacterial infection remains elusive. We show that ISG15 expression in nonphagocytic cells is dramatically induced upon Listeria infection. Surprisingly this induction can be type I interferon independent and depends on the cytosolic surveillance pathway, which senses bacterial DNA and signals through STING, TBK1, IRF3 and IRF7. Most importantly, we observed that ISG15 expression restricts Listeria infection in vitro and in vivo. We made use of stable isotope labeling in tissue culture (SILAC) to identify ISGylated proteins that could be responsible for the protective effect. Strikingly, infection or overexpression of ISG15 leads to ISGylation of ER and Golgi proteins, which correlates with increased secretion of cytokines known to counteract infection. Together, our data reveal a previously uncharacterized ISG15-dependent restriction of Listeria infection, reinforcing the view that ISG15 is a key component of the innate immune response. DOI:http://dx.doi.org/10.7554/eLife.06848.001 Listeria monocytogenes is a bacterium that can cause serious food poisoning in humans. Infections with this bacterium can be particularly dangerous to young children, pregnant women, the elderly, and individuals with weakened immune systems because they are more susceptible to developing serious complications that can sometimes lead to death. The bacteria infect cells in the lining of the human gut. Cells that detect the bacteria respond by producing proteins called interferons and other signaling proteins that activate the body's immune system to fight the infection. One of the genes that the interferons activate encodes a protein called ISG15, which helps to defend the body against viruses. However, it is not clear what role ISG15 plays in fighting bacterial infections. Here, Radoshevich et al. studied the role of ISG15 in human cells exposed to L. monocytogenes. The experiments show that ISG15 levels increase in the cells, but that the initial increase does not depend on Interferon proteins. Instead, ISG15 production is triggered by an alternative pathway called the cytosolic surveillance pathway, which is activated by the presence of bacterial DNA inside the cell. Further experiments found that ISG15 can counteract the infections of L. monocytogenes both in cells grown in cultures and in living mice. ISG15 modifies other proteins in the cell to promote the release of proteins called cytokines that help the body to eliminate the bacteria. Radoshevich et al.'s findings reveal a new role for ISG15 in fighting bacterial infections. A future challenge will be to understand the molecular details of how ISG15 triggers the release of cytokines. DOI:http://dx.doi.org/10.7554/eLife.06848.002
Collapse
Affiliation(s)
| | | | | | | | | | | | - Hélène Bierne
- Institut National de la Recherche Agronomique, UMR1319, Micalis, AgroParisTech, Jouy-en-Josas, France
| | | | | | - Klaus-Peter Knobeloch
- Molecular Genetics Group, Neuropathologie, Universitätsklinikum Freiburg, Freiburg, Germany
| | | |
Collapse
|
29
|
Parakh S, Atkin JD. Novel roles for protein disulphide isomerase in disease states: a double edged sword? Front Cell Dev Biol 2015; 3:30. [PMID: 26052512 PMCID: PMC4439577 DOI: 10.3389/fcell.2015.00030] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 04/28/2015] [Indexed: 12/14/2022] Open
Abstract
Protein disulphide isomerase (PDI) is a multifunctional redox chaperone of the endoplasmic reticulum (ER). Since it was first discovered 40 years ago the functions ascribed to PDI have evolved significantly and recent studies have recognized its distinct functions, with adverse as well as protective effects in disease. Furthermore, post translational modifications of PDI abrogate its normal functional roles in specific disease states. This review focusses on recent studies that have identified novel functions for PDI relevant to specific diseases.
Collapse
Affiliation(s)
- Sonam Parakh
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University Sydney, NSW, Australia
| | - Julie D Atkin
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Macquarie University Sydney, NSW, Australia ; Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University Bundoora, VIC, Australia
| |
Collapse
|
30
|
Kimura T, Endo S, Inui M, Saitoh SI, Miyake K, Takai T. Endoplasmic Protein Nogo-B (RTN4-B) Interacts with GRAMD4 and Regulates TLR9-Mediated Innate Immune Responses. THE JOURNAL OF IMMUNOLOGY 2015; 194:5426-36. [PMID: 25917084 DOI: 10.4049/jimmunol.1402006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 03/05/2015] [Indexed: 12/18/2022]
Abstract
TLRs are distributed in their characteristic cellular or subcellular compartments to efficiently recognize specific ligands and to initiate intracellular signaling. Whereas TLRs recognizing pathogen-associated lipids or proteins are localized to the cell surface, nucleic acid-sensing TLRs are expressed in endosomes and lysosomes. Several endoplasmic reticulum (ER)-resident proteins are known to regulate the trafficking of TLRs to the specific cellular compartments, thus playing important roles in the initiation of innate immune responses. In this study, we show that an ER-resident protein, Nogo-B (or RTN4-B), is necessary for immune responses triggered by nucleic acid-sensing TLRs, and that a newly identified Nogo-B-binding protein (glucosyltransferases, Rab-like GTPase activators and myotubularins [GRAM] domain containing 4 [GRAMD4]) negatively regulates the responses. Production of inflammatory cytokines in vitro by macrophages stimulated with CpG-B oligonucleotides or polyinosinic:polycytidylic acid was attenuated in the absence of Nogo-B, which was also confirmed in serum samples from Nogo-deficient mice injected with polyinosinic:polycytidylic acid. Although a deficiency of Nogo-B did not change the incorporation or delivery of CpG to endosomes, the localization of TLR9 to endolysosomes was found to be impaired. We identified GRAMD4 as a downmodulator for TLR9 response with a Nogo-B binding ability in ER, because our knockdown and overexpression experiments indicated that GRAMD4 suppresses the TLR9 response and knockdown of Gramd4 strongly enhanced the response in the absence of Nogo-B. Our findings indicate a critical role of Nogo-B and GRAMD4 in trafficking of TLR9.
Collapse
Affiliation(s)
- Toshifumi Kimura
- Department of Experimental Immunology, Institute of Development, Aging and Cancer, Tohoku University, Sendai 980-8575, Japan; and
| | - Shota Endo
- Department of Experimental Immunology, Institute of Development, Aging and Cancer, Tohoku University, Sendai 980-8575, Japan; and
| | - Masanori Inui
- Department of Experimental Immunology, Institute of Development, Aging and Cancer, Tohoku University, Sendai 980-8575, Japan; and
| | - Shin-Ichiroh Saitoh
- Division of Innate Immunity, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan
| | - Kensuke Miyake
- Division of Innate Immunity, Department of Microbiology and Immunology, Institute of Medical Science, University of Tokyo, Tokyo 108-8639, Japan
| | - Toshiyuki Takai
- Department of Experimental Immunology, Institute of Development, Aging and Cancer, Tohoku University, Sendai 980-8575, Japan; and
| |
Collapse
|
31
|
Conway ME, Harris M. S-nitrosylation of the thioredoxin-like domains of protein disulfide isomerase and its role in neurodegenerative conditions. Front Chem 2015; 3:27. [PMID: 25932462 PMCID: PMC4399332 DOI: 10.3389/fchem.2015.00027] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 03/30/2015] [Indexed: 12/14/2022] Open
Abstract
Correct protein folding and inhibition of protein aggregation is facilitated by a cellular “quality control system” that engages a network of protein interactions including molecular chaperones and the ubiquitin proteasome system. Key chaperones involved in these regulatory mechanisms are the protein disulfide isomerases (PDI) and their homologs, predominantly expressed in the endoplasmic reticulum of most tissues. Redox changes that disrupt ER homeostasis can lead to modification of these enzymes or chaperones with the loss of their proposed neuroprotective role resulting in an increase in protein misfolding. Misfolded protein aggregates have been observed in several disease states and are considered to play a pivotal role in the pathogenesis of neurodegenerative conditions such as Alzheimer's disease, Parkinson's disease, and Amyotrophic Lateral sclerosis. This review will focus on the importance of the thioredoxin-like CGHC active site of PDI and how our understanding of this structural motif will play a key role in unraveling the pathogenic mechanisms that underpin these neurodegenerative conditions.
Collapse
Affiliation(s)
- Myra E Conway
- Department of Applied Sciences, University of the West of England Bristol, UK
| | - Matthew Harris
- Department of Applied Sciences, University of the West of England Bristol, UK
| |
Collapse
|
32
|
Welte C, Engel S, Stuermer CAO. Upregulation of the zebrafish Nogo-A homologue, Rtn4b, in retinal ganglion cells is functionally involved in axon regeneration. Neural Dev 2015; 10:6. [PMID: 25888884 PMCID: PMC4374419 DOI: 10.1186/s13064-015-0034-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 03/04/2015] [Indexed: 11/10/2022] Open
Abstract
Background In contrast to mammals, zebrafish successfully regenerate retinal ganglion cell (RGC) axons after optic nerve section (ONS). This difference is explained on the one hand by neurite growth inhibitors in mammals (including Nogo-A), as opposed to growth-promoting glial cells in the fish visual pathway, and on the other hand by the neuron-intrinsic properties allowing the upregulation of growth-associated proteins in fish RGCs but not in mammals. Results Here, we report that Rtn4b, the zebrafish homologue of mammalian Nogo-A/RTN4-A, is upregulated in axotomized zebrafish RGCs and is primarily associated with the endoplasmic reticulum (ER). Rtn4b functions as a neuron-intrinsic determinant for axon regeneration, as was shown by downregulating Rtn4b through retrogradely transported morpholinos (MOs), applied to the optic nerve at the time of ONS. MO1 and MO2 reduced the number of axons from retina explants in a concentration-dependent manner. With MO1, the reduction was 55% (70 μM MO1) and 74% (140 μM MO1), respectively, with MO2: 59% (70 μM MO2) and 73% (140 μM MO2), respectively (compared to the control MO-treated side). Moreover, regenerating axons 7d after ONS and MO1 or MO2 application were labeled by Alexa488, applied distal to the first lesion. The number of Alexa488 labeled RGCs, containing the Rtn4b MO1 or MO2, was reduced by 54% and 62%, respectively, over control MO. Conclusions Thus, Rtn4b is an important neuron-intrinsic component and required for the success of axon regeneration in the zebrafish visual system. The spontaneous lesion-induced upregulation of Rtn4b in fish correlates with an increase in ER, soma size, biosynthetic activity, and thus growth and predicts that mammalian neurons require the same upregulation in order to successfully regenerate RGC axons.
Collapse
Affiliation(s)
- Cornelia Welte
- Department of Biology, University of Konstanz, Universitätsstraße 10, 78457, Konstanz, Germany.
| | - Sarah Engel
- Department of Biology, University of Konstanz, Universitätsstraße 10, 78457, Konstanz, Germany.
| | - Claudia A O Stuermer
- Department of Biology, University of Konstanz, Universitätsstraße 10, 78457, Konstanz, Germany.
| |
Collapse
|
33
|
Dai X, Sun Z, Liang R, Li Y, Luo H, Huang Y, Chen M, Su Z, Xiao F. Recombinant Nogo-66 via soluble expression with SUMO fusion in Escherichia coli inhibits neurite outgrowth in vitro. Appl Microbiol Biotechnol 2015; 99:5997-6007. [PMID: 25758955 DOI: 10.1007/s00253-015-6477-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 02/10/2015] [Accepted: 02/12/2015] [Indexed: 11/28/2022]
Abstract
Nogo-66, a hydrophilic loop of 66 amino acids flank two hydrophobic domains of the Nogo-A C terminus, interacts with the Nogo-66 receptor (NgR) to exert numerous functions in the central nervous system (CNS). Nogo-66 has important roles in aspects of neuronal development, including cell migration, axon guidance, fasciculation, and dendritic branching, and in aspects of CNS plasticity, including oligodendrocyte differentiation and myelination. Here, the small ubiquitin-related modifier (SUMO) was fused to the target gene, Nogo-66, and the construct was expressed in Escherichia coli (E. coli). Under the optimal fermentation conditions, the soluble expression level of the fusion protein was 33 % of the total supernatant protein. After cleaving the fusion proteins with SUMO protease and purifying them by Ni-NTA affinity chromatography, the yield and purity of recombinant Nogo-66 obtained by 10-L scale fermentation were 23 ± 1.5 mg/L and greater than 93 %, respectively. The authenticity of the recombinant Nogo-66 was confirmed by an electrospray ionization-mass spectrometry analysis. The functional analyses indicated that the recombinant Nogo-66 was capable of binding the NgR specifically. The immunofluorescence results showed that the recombinant Nogo-66 could significantly inhibit neurite outgrowth of rat pheochromocytoma (PC12) cells stimulated by nerve growth factor and cerebellar granule cells (CGCs). Furthermore, Nogo-66 inhibited neurite outgrowth by increasing the level of phosphorylated Rho-associated coiled-coil-containing protein kinase 2 (ROCK2), collapsin response mediator protein 2 (CRMP2), and myosin light chain (MLC). This study provided a feasible and convenient production method for generating sufficient recombinant Nogo-66 for experimental and clinical applications.
Collapse
Affiliation(s)
- Xiaoyong Dai
- Guangdong Provincial Key Laboratory of Bioengineering Medicine, Jinan University, Guangzhou, 510632, People's Republic of China
| | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Aronica E, Baas F, Iyer A, ten Asbroek AL, Morello G, Cavallaro S. Molecular classification of amyotrophic lateral sclerosis by unsupervised clustering of gene expression in motor cortex. Neurobiol Dis 2015; 74:359-76. [DOI: 10.1016/j.nbd.2014.12.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 11/12/2014] [Accepted: 12/02/2014] [Indexed: 12/15/2022] Open
|
35
|
Hübner CA, Kurth I. Membrane-shaping disorders: a common pathway in axon degeneration. ACTA ACUST UNITED AC 2014; 137:3109-21. [PMID: 25281866 DOI: 10.1093/brain/awu287] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Neurons with long projections are particularly liable to damage, which is reflected by a large group of hereditary neurodegenerative disorders that primarily affect these neurons. In the group of hereditary spastic paraplegias motor axons of the central nervous system degenerate, while distal pure motor neuropathies, Charcot-Marie-Tooth disorders and the group of hereditary sensory and autonomic neuropathies are characterized by degeneration of peripheral nerve fibres. Because the underlying pathologies share many parallels, the disorders are also referred to as axonopathies. A large number of genes has been associated with axonopathies and one of the emerging subgroups encodes membrane-shaping proteins with a central reticulon homology domain. Association of these proteins with lipid bilayers induces positive membrane curvature and influences the architecture of cellular organelles. Membrane-shaping proteins closely cooperate and directly interact with each other, but their structural features and localization to distinct subdomains of organelles suggests mutually exclusive roles. In some individuals a mutation in a shaping protein can result in upper motor neuron dysfunction, whereas in other patients it can lead to a degeneration of peripheral neurons. This suggests that membrane-shaping disorders might be considered as a continuous disease-spectrum of the axon.
Collapse
Affiliation(s)
- Christian A Hübner
- Institute of Human Genetics, Jena University Hospital, 07743 Jena, Germany
| | - Ingo Kurth
- Institute of Human Genetics, Jena University Hospital, 07743 Jena, Germany
| |
Collapse
|
36
|
Wu XF, Wang AF, Chen L, Huang EP, Xie WB, Liu C, Huang WY, Chen CX, Qiu PM, Wang HJ. S-Nitrosylating protein disulphide isomerase mediates α-synuclein aggregation caused by methamphetamine exposure in PC12 cells. Toxicol Lett 2014; 230:19-27. [PMID: 25090657 DOI: 10.1016/j.toxlet.2014.07.026] [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: 05/02/2014] [Revised: 07/08/2014] [Accepted: 07/24/2014] [Indexed: 12/21/2022]
Abstract
Methamphetamine (METH) belongs to Amphetamine-type stimulants, METH abusers are at high risk of neurodegenerative disorders, including Parkinson's disease (PD). However, there are still no effective treatments to METH-induced neurodegeneration because its mechanism remains unknown. In order to investigate METH's neurotoxic mechanism, we established an in vitro PD pathology model by exposing PC12 cells to METH. We found the expression of nitric oxide synthase (NOS), nitric oxide (NO) and α-synuclein (α-syn) was significantly increased after METH treatment for 24h, in addition, the aggregattion of α-syn and the S-nitrosylation of protein disulphideisomerase(PDI) were also obviously enhanced. When we exposed PC12 cells to the NOS inhibitor N-nitro-L-arginine(L-NNA) with METH together, the L-NNA obviously inhibited these changes induced by METH. While when we exposed PC12 cells to the precursor of NO L-Arginine together with METH, the L-Arginine resulted in the opposite effect compared to L-NNA. And when we knocked down the PDI gene, the L-NNA did not have this effect. Therefore, PDI plays a significant role in neurological disorders related to α-syn aggregation, and it suggests that PDI could be as a potential target to prevent METH-induced neurodegeneration.
Collapse
Affiliation(s)
- Xiao-Fang Wu
- Department of Forensic Medicine, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province 510515, PR China.
| | - Ai-Feng Wang
- Department of Forensic Medicine, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province 510515, PR China
| | - Ling Chen
- Department of Forensic Medicine, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province 510515, PR China
| | - En-Ping Huang
- Department of Forensic Medicine, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province 510515, PR China
| | - Wei-Bing Xie
- Department of Forensic Medicine, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province 510515, PR China
| | - Chao Liu
- Guangzhou Forensic Science Institute, Guangzhou, Guangdong Province 510030, PR China
| | - Wei-Ye Huang
- Department of Forensic Medicine, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province 510515, PR China
| | - Chuan-Xiang Chen
- Department of Forensic Medicine, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province 510515, PR China
| | - Ping-Ming Qiu
- Department of Forensic Medicine, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province 510515, PR China.
| | - Hui-Jun Wang
- Department of Forensic Medicine, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong Province 510515, PR China.
| |
Collapse
|
37
|
Atkin JD, Farg MA, Soo KY, Walker AK, Halloran M, Turner BJ, Nagley P, Horne MK. Mutant SOD1 inhibits ER-Golgi transport in amyotrophic lateral sclerosis. J Neurochem 2014; 129:190-204. [PMID: 24134191 DOI: 10.1111/jnc.12493] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 09/16/2013] [Accepted: 10/15/2013] [Indexed: 12/16/2022]
Abstract
Cu/Zn-superoxide dismutase is misfolded in familial and sporadic amyotrophic lateral sclerosis, but it is not clear how this triggers endoplasmic reticulum (ER) stress or other pathogenic processes. Here, we demonstrate that mutant SOD1 (mSOD1) is predominantly found in the cytoplasm in neuronal cells. Furthermore, we show that mSOD1 inhibits secretory protein transport from the ER to Golgi apparatus. ER-Golgi transport is linked to ER stress, Golgi fragmentation and axonal transport and we also show that inhibition of ER-Golgi trafficking preceded ER stress, Golgi fragmentation, protein aggregation and apoptosis in cells expressing mSOD1. Restoration of ER-Golgi transport by over-expression of coatomer coat protein II subunit Sar1 protected against inclusion formation and apoptosis, thus linking dysfunction in ER-Golgi transport to cellular pathology. These findings thus link several cellular events in amyotrophic lateral sclerosis into a single mechanism occurring early in mSOD1 expressing cells.
Collapse
Affiliation(s)
- Julie D Atkin
- Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Melbourne, Australia; Department of Florey Neuroscience, University of Melbourne, Parkville, Melbourne, Australia
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Protein disulfide isomerase: a promising target for cancer therapy. Drug Discov Today 2014; 19:222-40. [DOI: 10.1016/j.drudis.2013.10.017] [Citation(s) in RCA: 168] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 09/12/2013] [Accepted: 10/22/2013] [Indexed: 12/15/2022]
|
39
|
Arl6IP1 has the ability to shape the mammalian ER membrane in a reticulon-like fashion. Biochem J 2014; 458:69-79. [DOI: 10.1042/bj20131186] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The present study characterizes Arl6IP1, an anti-apoptotic regulator, in the context of a protein harbouring the reticulon-homology domain. We demonstrate that Arl6IP1 has the ability to bind to atlastin and shape the ER tubules in a reticulon-like fashion.
Collapse
|
40
|
Grek C, Townsend D. Protein Disulfide Isomerase Superfamily in Disease and the Regulation of Apoptosis. ENDOPLASMIC RETICULUM STRESS IN DISEASES 2014; 1:4-17. [PMID: 25309899 PMCID: PMC4192724 DOI: 10.2478/ersc-2013-0001] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cellular homeostasis requires the balance of a multitude of signaling cascades that are contingent upon the essential proteins being properly synthesized, folded and delivered to appropriate subcellular locations. In eukaryotic cells the endoplasmic reticulum (ER) is a specialized organelle that is the central site of synthesis and folding of secretory, membrane and a number of organelletargeted proteins. The integrity of protein folding is enabled by the presence of ATP, Ca++, molecular chaperones, as well as an oxidizing redox environment. The imbalance between the load and capacity of protein folding results in a cellular condition known as ER stress. Failure of these pathways to restore ER homeostasis results in the activation of apoptotic pathways. Protein disulfide isomerases (PDI) compose a superfamily of oxidoreductases that have diverse sequences and are localized in the ER, nucleus, cytosol, mitochondria and cell membrane. The PDI superfamily has multiple functions including, acting as molecular chaperones, protein-binding partners, and hormone reservoirs. Recently, PDI family members have been implicated in the regulation of apoptotic signaling events. The complexities underlying the molecular mechanisms that define the switch from pro-survival to pro-death response are evidenced by recent studies that reveal the roles of specific chaperone proteins as integration points in signaling pathways that determine cell fate. The following review discusses the dual role of PDI in cell death and survival during ER stress.
Collapse
Affiliation(s)
- C. Grek
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics
| | - D.M. Townsend
- Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC 29425
| |
Collapse
|
41
|
González C, Couve A. The axonal endoplasmic reticulum and protein trafficking: Cellular bootlegging south of the soma. Semin Cell Dev Biol 2013; 27:23-31. [PMID: 24361785 DOI: 10.1016/j.semcdb.2013.12.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 11/18/2013] [Accepted: 12/05/2013] [Indexed: 12/26/2022]
Abstract
Neurons are responsible for the generation and propagation of electrical impulses, which constitute the central mechanism of information transfer between the nervous system and internal or external environments. Neurons are large and polarized cells with dendrites and axons constituting their major functional domains. Axons are thin and extremely long specializations that mediate the conduction of these electrical impulses. Regulation of the axonal proteome is fundamental to generate and maintain neural function. Although classical mechanisms of protein transport have been around for decades, a variety newly identified mechanisms to control the abundance of axonal proteins have appeared in recent years. Here we briefly describe the classical models of axonal transport and compare them to the emerging concepts of axonal biosynthesis centered on the endoplasmic reticulum. We review the structure of the axonal endoplasmic reticulum, and its role in diffusion and trafficking of axonal proteins. We also analyze the contribution of other secretory organelles to axonal trafficking and evaluate the potential consequences of axonal endoplasmic reticulum malfunction in neuropathology.
Collapse
Affiliation(s)
- Carolina González
- Program of Physiology and Biophysics, Institute of Biomedical Sciences (ICBM) and Biomedical Neuroscience Institute (BNI), Faculty of Medicine, Universidad de Chile, Santiago, Chile
| | - Andrés Couve
- Program of Physiology and Biophysics, Institute of Biomedical Sciences (ICBM) and Biomedical Neuroscience Institute (BNI), Faculty of Medicine, Universidad de Chile, Santiago, Chile.
| |
Collapse
|
42
|
Walker AK, Soo KY, Sundaramoorthy V, Parakh S, Ma Y, Farg MA, Wallace RH, Crouch PJ, Turner BJ, Horne MK, Atkin JD. ALS-associated TDP-43 induces endoplasmic reticulum stress, which drives cytoplasmic TDP-43 accumulation and stress granule formation. PLoS One 2013; 8:e81170. [PMID: 24312274 PMCID: PMC3843686 DOI: 10.1371/journal.pone.0081170] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 10/09/2013] [Indexed: 12/12/2022] Open
Abstract
In amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration, TAR DNA binding protein 43 (TDP-43) accumulates in the cytoplasm of affected neurons and glia, where it associates with stress granules (SGs) and forms large inclusions. SGs form in response to cellular stress, including endoplasmic reticulum (ER) stress, which is induced in both familial and sporadic forms of ALS. Here we demonstrate that pharmacological induction of ER stress causes TDP-43 to accumulate in the cytoplasm, where TDP-43 also associates with SGs. Furthermore, treatment with salubrinal, an inhibitor of dephosphorylation of eukaryotic initiation factor 2-α, a key modulator of ER stress, potentiates ER stress-mediated SG formation. Inclusions of C-terminal fragment TDP-43, reminiscent of disease-pathology, form in close association with ER and Golgi compartments, further indicating the involvement of ER dysfunction in TDP-43-associated disease. Consistent with this notion, over-expression of ALS-linked mutant TDP-43, and to a lesser extent wildtype TDP-43, triggers several ER stress pathways in neuroblastoma cells. Similarly, we found an interaction between the ER chaperone protein disulphide isomerase and TDP-43 in transfected cell lysates and in the spinal cords of mutant A315T TDP-43 transgenic mice. This study provides evidence for ER stress as a pathogenic pathway in TDP-43-mediated disease.
Collapse
Affiliation(s)
- Adam K. Walker
- Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria, Australia
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Kai Y. Soo
- Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria, Australia
| | - Vinod Sundaramoorthy
- Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria, Australia
| | - Sonam Parakh
- Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria, Australia
| | - Yi Ma
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Manal A. Farg
- Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria, Australia
| | - Robyn H. Wallace
- Queensland Brain Institute and School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
| | - Peter J. Crouch
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
- Department of Pathology, The University of Melbourne, Parkville, Victoria, Australia
| | - Bradley J. Turner
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
| | - Malcolm K. Horne
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
- Florey Department of Neuroscience and Mental Health, Faculty of Medicine, Dentistry & Health Sciences, The University of Melbourne, Parkville, Victoria, Australia
- Saint Vincent's Hospital, Fitzroy, Victoria, Australia
| | - Julie D. Atkin
- Department of Biochemistry, La Trobe Institute for Molecular Science, La Trobe University, Bundoora, Victoria, Australia
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia
- * E-mail:
| |
Collapse
|
43
|
Nogo-A couples with Apg-1 through interaction and co-ordinate expression under hypoxic and oxidative stress. Biochem J 2013; 455:217-27. [PMID: 23909438 PMCID: PMC3806365 DOI: 10.1042/bj20130579] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Nogo-A is the largest isoform of the Nogo/RTN4 (reticulon 4) proteins and has been characterized as a major myelin-associated inhibitor of regenerative nerve growth in the adult CNS (central nervous system). Apart from the myelin sheath, Nogo-A is expressed at high levels in principal neurons of the CNS. The specificity of Nogo-A resides in its central domain, NiG. We identified Apg-1, a member of the stress-induced Hsp110 (heat-shock protein of 110 kDa) family, as a novel interactor of NiG/Nogo-A. The interaction is selective because Apg-1 interacts with Nogo-A/RTN4-A, but not with RTN1-A, the closest paralogue of Nogo-A. Conversely, Nogo-A binds to Apg-1, but not to Apg-2 or Hsp105, two other members of the Hsp110 family. We characterized the Nogo-A–Apg-1 interaction by affinity precipitation, co-immunoprecipitation and proximity ligation assay, using primary hippocampal neurons derived from Nogo-deficient mice. Under conditions of hypoxic and oxidative stress we found that Nogo-A and Apg-1 were tightly co-regulated in hippocampal neurons. Although both proteins were up-regulated under hypoxic conditions, their expression levels were reduced upon the addition of hydrogen peroxide. Taken together, we suggest that Nogo-A is closely involved in the neuronal response to hypoxic and oxidative stress, an observation that may be of relevance not only in stroke-induced ischaemia, but also in neuroblastoma formation. The nerve growth inhibitor Nogo-A selectively binds to the heat-shock protein Apg-1 and the expression levels of these two interactors are co-regulated under different forms of stress in neurons.
Collapse
|
44
|
Halloran M, Parakh S, Atkin JD. The role of s-nitrosylation and s-glutathionylation of protein disulphide isomerase in protein misfolding and neurodegeneration. Int J Cell Biol 2013; 2013:797914. [PMID: 24348565 PMCID: PMC3852308 DOI: 10.1155/2013/797914] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 08/19/2013] [Accepted: 09/02/2013] [Indexed: 12/13/2022] Open
Abstract
Neurodegenerative diseases involve the progressive loss of neurons, and a pathological hallmark is the presence of abnormal inclusions containing misfolded proteins. Although the precise molecular mechanisms triggering neurodegeneration remain unclear, endoplasmic reticulum (ER) stress, elevated oxidative and nitrosative stress, and protein misfolding are important features in pathogenesis. Protein disulphide isomerase (PDI) is the prototype of a family of molecular chaperones and foldases upregulated during ER stress that are increasingly implicated in neurodegenerative diseases. PDI catalyzes the rearrangement and formation of disulphide bonds, thus facilitating protein folding, and in neurodegeneration may act to ameliorate the burden of protein misfolding. However, an aberrant posttranslational modification of PDI, S-nitrosylation, inhibits its protective function in these conditions. S-nitrosylation is a redox-mediated modification that regulates protein function by covalent addition of nitric oxide- (NO-) containing groups to cysteine residues. Here, we discuss the evidence for abnormal S-nitrosylation of PDI (SNO-PDI) in neurodegeneration and how this may be linked to another aberrant modification of PDI, S-glutathionylation. Understanding the role of aberrant S-nitrosylation/S-glutathionylation of PDI in the pathogenesis of neurodegenerative diseases may provide insights into novel therapeutic interventions in the future.
Collapse
Affiliation(s)
- M. Halloran
- Department of Neuroscience in the School of Psychological Science, La Trobe University, Bundoora, VIC 3086, Australia
| | - S. Parakh
- Department of Biochemistry, La Trobe University, Bundoora, VIC 3086, Australia
| | - J. D. Atkin
- Department of Biochemistry, La Trobe University, Bundoora, VIC 3086, Australia
| |
Collapse
|
45
|
Chiurchiù V, Maccarrone M, Orlacchio A. The role of reticulons in neurodegenerative diseases. Neuromolecular Med 2013; 16:3-15. [PMID: 24218324 PMCID: PMC3918113 DOI: 10.1007/s12017-013-8271-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 10/23/2013] [Indexed: 01/08/2023]
Abstract
Reticulons (RTNs) are a group of membrane-associated proteins mainly responsible for shaping the tubular endoplasmic reticulum network, membrane trafficking, inhibition of axonal growth, and apoptosis. These proteins share a common sequence feature, the reticulon homology domain, which consists of paired hydrophobic stretches that are believed to induce membrane curvature by acting as a wedge in bilayer membranes. RTNs are ubiquitously expressed in all tissues, but each RTN member exhibits a unique expression pattern that prefers certain tissues or even cell types. Recently, accumulated evidence has suggested additional and unexpected roles for RTNs, including those on DNA binding, autophagy, and several inflammatory-related functions. These manifold actions of RTNs account for their ever-growing recognition of their involvement in neurodegenerative diseases like Alzheimer's disease, amyotrophic lateral sclerosis, multiple sclerosis, as well as hereditary spastic paraplegia. This review summarizes the latest discoveries on RTNs in human pathophysiology, and the engagement of these in neurodegeneration, along with the implications of these findings for a better understanding of the molecular events triggered by RTNs and their potential exploitation as next-generation therapeutics.
Collapse
Affiliation(s)
- Valerio Chiurchiù
- Laboratorio di Neurochimica dei Lipidi, Centro Europeo di Ricerca sul Cervello (CERC) - Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Santa Lucia, Rome, Italy
| | | | | |
Collapse
|
46
|
Goyal U, Blackstone C. Untangling the web: mechanisms underlying ER network formation. BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1833:2492-8. [PMID: 23602970 PMCID: PMC3729797 DOI: 10.1016/j.bbamcr.2013.04.009] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Revised: 04/04/2013] [Accepted: 04/08/2013] [Indexed: 12/16/2022]
Abstract
The ER is a continuous membrane system consisting of the nuclear envelope, flat sheets often studded with ribosomes, and a polygonal network of highly-curved tubules extending throughout the cell. Although protein and lipid biosynthesis, protein modification, vesicular transport, Ca(2+)dynamics, and protein quality control have been investigated in great detail, mechanisms that generate the distinctive architecture of the ER have been uncovered only recently. Several protein families including the reticulons and REEPs/DP1/Yop1p harbor hydrophobic hairpin domains that shape high-curvature ER tubules and mediate intramembrane protein interactions. Members of the atlastin/RHD3/Sey1p family of dynamin-related GTPases interact with the ER-shaping proteins and mediate the formation of three-way junctions responsible for the polygonal structure of the tubular ER network, with Lunapark proteins acting antagonistically. Additional classes of tubular ER proteins including some REEPs and the M1 spastin ATPase interact with the microtubule cytoskeleton. Flat ER sheets possess a different complement of proteins such as p180, CLIMP-63 and kinectin implicated in shaping, cisternal stacking and cytoskeletal interactions. The ER is also in constant motion, and numerous signaling pathways as well as interactions among cytoskeletal elements, the plasma membrane, and organelles cooperate to position and shape the ER dynamically. Finally, many proteins involved in shaping the ER network are mutated in the most common forms of hereditary spastic paraplegia, indicating a particular importance for proper ER morphology and distribution in large, highly-polarized cells such as neurons. This article is part of a Special Issue entitled: Functional and structural diversity of endoplasmic reticulum.
Collapse
Affiliation(s)
- Uma Goyal
- Cell Biology Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Craig Blackstone
- Cell Biology Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| |
Collapse
|
47
|
Potential effect of S-nitrosylated protein disulfide isomerase on mutant SOD1 aggregation and neuronal cell death in amyotrophic lateral sclerosis. Mol Neurobiol 2013; 49:796-807. [PMID: 24091828 DOI: 10.1007/s12035-013-8562-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Accepted: 09/22/2013] [Indexed: 12/11/2022]
Abstract
Aggregation of misfolded protein and resultant intracellular inclusion body formation are common hallmarks of mutant superoxide dismutase (mSOD1)-linked familial amyotrophic lateral sclerosis (FALS) and have been associated with the selective neuronal death. Protein disulfide isomerase (PDI) represents a family of enzymatic chaperones that can fold nascent and aberrant proteins in the endoplasmic reticulum (ER) lumen. Recently, our group found that S-nitrosylated PDI could contribute to protein misfolding and subsequent neuronal cell death. However, the exact role of PDI in the pathogenesis of ALS remains unclear. In this study, we propose that PDI attenuates aggregation of mutant/misfolded SOD1 and resultant neurotoxicity associated with ER stress. ER stress resulting in PDI dysfunction therefore provides a mechanistic link between deficits in molecular chaperones, accumulation of misfolded proteins, and neuronal death in neurodegenerative diseases. In contrast, S-nitrosylation of PDI inhibits its activity, increases mSOD1 aggregation, and increases neuronal cell death. Specifically, our data show that S-nitrosylation abrogates PDI-mediated attenuation of neuronal cell death triggered by thapsigargin. Biotin switch assays demonstrate S-nitrosylated PDI both in the spinal cords of SOD1 (G93A) mice and human patients with sporadic ALS. Therefore, denitrosylation of PDI may have therapeutic implications. Taken together, our results suggest a novel strategy involving PDI as a therapy to prevent mSOD1 aggregation and neuronal degeneration. Moreover, the data demonstrate that inactivation of PDI by S-nitrosylation occurs in both mSOD1-linked and sporadic forms of ALS in humans as well as mice.
Collapse
|
48
|
Protrudin binds atlastins and endoplasmic reticulum-shaping proteins and regulates network formation. Proc Natl Acad Sci U S A 2013; 110:14954-9. [PMID: 23969831 DOI: 10.1073/pnas.1307391110] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Hereditary spastic paraplegias are inherited neurological disorders characterized by progressive lower-limb spasticity and weakness. Although more than 50 genetic loci are known [spastic gait (SPG)1 to -57], over half of hereditary spastic paraplegia cases are caused by pathogenic mutations in four genes encoding proteins that function in tubular endoplasmic reticulum (ER) network formation: atlastin-1 (SPG3A), spastin (SPG4), reticulon 2 (SPG12), and receptor expression-enhancing protein 1 (SPG31). Here, we show that the SPG33 protein protrudin contains hydrophobic, intramembrane hairpin domains, interacts with tubular ER proteins, and functions in ER morphogenesis by regulating the sheet-to-tubule balance and possibly the density of tubule interconnections. Protrudin also interacts with KIF5 and harbors a Rab-binding domain, a noncanonical FYVE (Fab-1, YGL023, Vps27, and EEA1) domain, and a two phenylalanines in an acidic tract (FFAT) domain and, thus, may also function in the distribution of ER tubules via ER contacts with the plasma membrane or other organelles.
Collapse
|
49
|
Crosstalk between Endoplasmic Reticulum Stress and Protein Misfolding in Neurodegenerative Diseases. ACTA ACUST UNITED AC 2013. [DOI: 10.1155/2013/256404] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Under physiological conditions, the endoplasmic reticulum (ER) is a central subcellular compartment for protein quality control in the secretory pathway that prevents protein misfolding and aggregation. Instrumental in protein quality control in the ER is the unfolded protein response (UPR), which is activated upon ER stress to reestablish homeostasis through a sophisticated transcriptionally and translationally regulated signaling network. However, this response can lead to apoptosis if the stress cannot be alleviated. The presence of abnormal protein aggregates containing specific misfolded proteins is recognized as the basis of numerous human conformational disorders, including neurodegenerative diseases. Here, I will highlight the overwhelming evidence that the presence of specific aberrant proteins in Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), prion diseases, and Amyotrophic Lateral Sclerosis (ALS) is intimately associated with perturbations in the ER protein quality control machinery that become incompetent to restore protein homeostasis and shift adaptive programs toward the induction of apoptotic signaling to eliminate irreversibly damaged neurons. Increasing our understanding about the deadly crosstalk between ER dysfunction and protein misfolding in these neurodegenerative diseases may stimulate the development of novel therapeutic strategies able to support neuronal survival and ameliorate disease progression.
Collapse
|
50
|
Kwok CT, Morris AG, Frampton J, Smith B, Shaw CE, de Belleroche J. Association studies indicate that protein disulfide isomerase is a risk factor in amyotrophic lateral sclerosis. Free Radic Biol Med 2013; 58:81-6. [PMID: 23337974 DOI: 10.1016/j.freeradbiomed.2013.01.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Revised: 11/27/2012] [Accepted: 01/03/2013] [Indexed: 11/28/2022]
Abstract
Protein disulfide isomerase (PDI) plays an important role in the endoplasmic reticulum (ER) by facilitating the exchange of disulfide bonds and, together with other ER stress proteins, is induced in amyotrophic lateral sclerosis (ALS). However, genetic polymorphisms in the P4HB gene, which encodes PDI, have not been thoroughly investigated in ALS cases. In this study, we determined whether single-nucleotide polymorphisms (SNPs) in the P4HB gene were associated with familial ALS (FALS) and sporadic ALS (SALS). We report significant genotypic associations for two SNPs in P4HB with FALS, rs876016 (P=0.0198) and rs2070872 (P=0.0046), all values being FDR corrected. Significant allelic associations were also obtained for rs876016 with FALS (P=0.0155) and ALS (FALS and SALS) (P=0.0148). Four SNP haplotypes, which included two additional flanking SNPs, rs876017 and rs8324, were examined and rare haplotypes were found to be more common in ALS cases compared to controls. Seven haplotypes were significantly associated with FALS and one haplotype was significantly associated with SALS. One rare haplotype, which was present in controls, was overrepresented in a group of SOD1-positive FALS cases. Reduced survival was observed in FALS cases possessing at least one copy of the minor allele of rs2070872 (P=0.0059) and rs8324 (P=0.0167) and in individuals lacking the homozygous AAAC/AAAC diplotype (P=0.011). The results suggest that P4HB is a modifier gene in ALS susceptibility and may represent a potential therapeutic target for ALS.
Collapse
Affiliation(s)
- Chun Tak Kwok
- Neurogenetics Group, Division of Brain Sciences, Faculty of Medicine, Imperial College London, London W12 0NN, UK
| | | | | | | | | | | |
Collapse
|