201
|
Simon NG. Lower motor neurons - Counting cogs in the ALS machine. Clin Neurophysiol 2016; 127:2668-9. [PMID: 27102133 DOI: 10.1016/j.clinph.2016.03.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 03/21/2016] [Indexed: 12/12/2022]
Affiliation(s)
- Neil G Simon
- St Vincent's Clinical School, University of New South Wales, Australia.
| |
Collapse
|
202
|
|
203
|
Villoslada P. Neuroprotective therapies for multiple sclerosis and other demyelinating diseases. ACTA ACUST UNITED AC 2016. [DOI: 10.1186/s40893-016-0004-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
204
|
Edens BM, Miller N, Ma YC. Impaired Autophagy and Defective Mitochondrial Function: Converging Paths on the Road to Motor Neuron Degeneration. Front Cell Neurosci 2016; 10:44. [PMID: 26973461 PMCID: PMC4776126 DOI: 10.3389/fncel.2016.00044] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 02/08/2016] [Indexed: 12/12/2022] Open
Abstract
Selective motor neuron degeneration is a hallmark of amyotrophic lateral sclerosis (ALS). Around 10% of all cases present as familial ALS (FALS), while sporadic ALS (SALS) accounts for the remaining 90%. Diverse genetic mutations leading to FALS have been identified, but the underlying causes of SALS remain largely unknown. Despite the heterogeneous and incompletely understood etiology, different types of ALS exhibit overlapping pathology and common phenotypes, including protein aggregation and mitochondrial deficiencies. Here, we review the current understanding of mechanisms leading to motor neuron degeneration in ALS as they pertain to disrupted cellular clearance pathways, ATP biogenesis, calcium buffering and mitochondrial dynamics. Through focusing on impaired autophagic and mitochondrial functions, we highlight how the convergence of diverse cellular processes and pathways contributes to common pathology in motor neuron degeneration.
Collapse
Affiliation(s)
- Brittany M. Edens
- Departments of Pediatrics, Neurology, and Physiology, Northwestern University Feinberg School of MedicineChicago, IL, USA
- Lurie Children’s Hospital of ChicagoChicago, IL, USA
| | - Nimrod Miller
- Departments of Pediatrics, Neurology, and Physiology, Northwestern University Feinberg School of MedicineChicago, IL, USA
- Lurie Children’s Hospital of ChicagoChicago, IL, USA
| | - Yong-Chao Ma
- Departments of Pediatrics, Neurology, and Physiology, Northwestern University Feinberg School of MedicineChicago, IL, USA
- Lurie Children’s Hospital of ChicagoChicago, IL, USA
| |
Collapse
|
205
|
Shen S, Benoy V, Bergman JA, Kalin JH, Frojuello M, Vistoli G, Haeck W, Van Den Bosch L, Kozikowski AP. Bicyclic-Capped Histone Deacetylase 6 Inhibitors with Improved Activity in a Model of Axonal Charcot-Marie-Tooth Disease. ACS Chem Neurosci 2016; 7:240-58. [PMID: 26599234 DOI: 10.1021/acschemneuro.5b00286] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Charcot-Marie-Tooth (CMT) disease is a disorder of the peripheral nervous system where progressive degeneration of motor and sensory nerves leads to motor problems and sensory loss and for which no pharmacological treatment is available. Recently, it has been shown in a model for the axonal form of CMT that histone deacetylase 6 (HDAC6) can serve as a target for the development of a pharmacological therapy. Therefore, we aimed at developing new selective and activity-specific HDAC6 inhibitors with improved biochemical properties. By utilizing a bicyclic cap as the structural scaffold from which to build upon, we developed several analogues that showed improved potency compared to tubastatin A while maintaining excellent selectivity compared to HDAC1. Further screening in N2a cells examining both the acetylation of α-tubulin and histones narrowed down the library of compounds to three potent and selective HDAC6 inhibitors. In mutant HSPB1-expressing DRG neurons, serving as an in vitro model for CMT2, these inhibitors were able to restore the mitochondrial axonal transport deficits. Combining structure-based development of HDAC6 inhibitors, screening in N2a cells and in a neuronal model for CMT2F, and preliminary ADMET and pharmacokinetic profiles, resulted in the selection of compound 23d that possesses improved biochemical, functional, and druglike properties compared to tubastatin A.
Collapse
Affiliation(s)
- Sida Shen
- Drug
Discovery Program, University of Illinois at Chicago, 833 S. Wood
St., Chicago, Illinois 60612, United States
| | - Veronick Benoy
- Laboratory of Neurobiology, Vesalius Research Center (VIB) and Leuven Research Institute for Neuroscience and Disease (LIND), KU Leuven, O&N4 Herestraat 49, B-3000 Leuven, Belgium
| | - Joel A. Bergman
- Drug
Discovery Program, University of Illinois at Chicago, 833 S. Wood
St., Chicago, Illinois 60612, United States
| | - Jay H. Kalin
- Drug
Discovery Program, University of Illinois at Chicago, 833 S. Wood
St., Chicago, Illinois 60612, United States
| | - Mariana Frojuello
- Drug
Discovery Program, University of Illinois at Chicago, 833 S. Wood
St., Chicago, Illinois 60612, United States
| | - Giulio Vistoli
- Dipartimento
di Scienze Farmaceutiche, Università degli Studi di Milano, Via Mangiagalli 25, 20133 Milano, Italy
| | - Wanda Haeck
- Laboratory of Neurobiology, Vesalius Research Center (VIB) and Leuven Research Institute for Neuroscience and Disease (LIND), KU Leuven, O&N4 Herestraat 49, B-3000 Leuven, Belgium
| | - Ludo Van Den Bosch
- Laboratory of Neurobiology, Vesalius Research Center (VIB) and Leuven Research Institute for Neuroscience and Disease (LIND), KU Leuven, O&N4 Herestraat 49, B-3000 Leuven, Belgium
| | - Alan P. Kozikowski
- Drug
Discovery Program, University of Illinois at Chicago, 833 S. Wood
St., Chicago, Illinois 60612, United States
| |
Collapse
|
206
|
There's Something Wrong with my MAM; the ER-Mitochondria Axis and Neurodegenerative Diseases. Trends Neurosci 2016; 39:146-157. [PMID: 26899735 PMCID: PMC4780428 DOI: 10.1016/j.tins.2016.01.008] [Citation(s) in RCA: 333] [Impact Index Per Article: 41.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 01/19/2016] [Accepted: 01/21/2016] [Indexed: 12/18/2022]
Abstract
Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis with associated frontotemporal dementia (ALS/FTD) are major neurodegenerative diseases for which there are no cures. All are characterised by damage to several seemingly disparate cellular processes. The broad nature of this damage makes understanding pathogenic mechanisms and devising new treatments difficult. Can the different damaged functions be linked together in a common disease pathway and which damaged function should be targeted for therapy? Many functions damaged in neurodegenerative diseases are regulated by communications that mitochondria make with a specialised region of the endoplasmic reticulum (ER; mitochondria-associated ER membranes or 'MAM'). Moreover, several recent studies have shown that disturbances to ER-mitochondria contacts occur in neurodegenerative diseases. Here, we review these findings.
Collapse
|
207
|
Kanakkanthara A, Northcote PT, Miller JH. Peloruside A: a lead non-taxoid-site microtubule-stabilizing agent with potential activity against cancer, neurodegeneration, and autoimmune disease. Nat Prod Rep 2016; 33:549-61. [PMID: 26867978 DOI: 10.1039/c5np00146c] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Covering: 2000 up to 2016Peloruside A, a macrocyclic secondary metabolite from a New Zealand marine sponge, Mycale hentscheli, has shown potent antiproliferative activity in cultured cancer cells as well as inhibitory effects on tumor growth in mouse models. The compound also has promising effects against cell models of neurodegenerative and autoimmune diseases. In mechanistic studies, peloruside A shares with paclitaxel (Taxol®) the ability to stabilize microtubules by binding to β-tubulin. Peloruside A, however, occupies a unique external site on β-tubulin that does not overlap the classical taxoid site that is located on the inside of the microtubule. As such, peloruside A has been of central importance in defining a new microtubule-stabilizer binding site localized on the exterior surface of the microtubule that has led to increased interest in the design of an upscaled total synthesis of the natural product and its analogues. Here, we review advances in the biochemical and biological validation of peloruside A as an attractive therapeutic candidate for the treatment of cancer, neurodegeneration, and autoimmune disease.
Collapse
Affiliation(s)
- Arun Kanakkanthara
- Department of Pediatric and Adolescent Medicine, Mayo Clinic, 200 First Street SW, Rochester, MN, USA 55905.
| | | | | |
Collapse
|
208
|
Korsak LIT, Mitchell ME, Shepard KA, Akins MR. Regulation of neuronal gene expression by local axonal translation. CURRENT GENETIC MEDICINE REPORTS 2016; 4:16-25. [PMID: 27722035 DOI: 10.1007/s40142-016-0085-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
RNA localization is a key mechanism in the regulation of protein expression. In neurons, this includes the axonal transport of select mRNAs based on the recognition of axonal localization motifs in these RNAs by RNA binding proteins. Bioinformatic analyses of axonal RNAs suggest that selective inclusion of such localization motifs in mature mRNAs is one mechanism controlling the composition of the axonal transcriptome. The subsequent translation of axonal transcripts in response to specific stimuli provides precise spatiotemporal control of the axonal proteome. This axonal translation supports local phenomena including axon pathfinding, mitochondrial function, and synapse-specific plasticity. Axonal protein synthesis also provides transport machinery and signals for retrograde trafficking to the cell body to effect somatic changes including altering the transcriptional program. Here we review the remarkable progress made in recent years to identify and characterize these phenomena.
Collapse
Affiliation(s)
- Lulu I T Korsak
- Drexel University, PISB 312; 3245 Chestnut St, Philadelphia, PA 19104,
| | - Molly E Mitchell
- Drexel University, PISB 312; 3245 Chestnut St, Philadelphia, PA 19104,
| | | | - Michael R Akins
- Assistant Professor, Department of Biology, Department of Neurobiology & Anatomy, Drexel University, PISB 319; 3245 Chestnut St, Philadelphia, PA 19104,
| |
Collapse
|
209
|
Krieger C, Wang SJH, Yoo SH, Harden N. Adducin at the Neuromuscular Junction in Amyotrophic Lateral Sclerosis: Hanging on for Dear Life. Front Cell Neurosci 2016; 10:11. [PMID: 26858605 PMCID: PMC4731495 DOI: 10.3389/fncel.2016.00011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 01/13/2016] [Indexed: 12/11/2022] Open
Abstract
The neurological dysfunction in amyotrophic lateral sclerosis (ALS)/motor neurone disease (MND) is associated with defective nerve-muscle contacts early in the disease suggesting that perturbations of cell adhesion molecules (CAMs) linking the pre- and post-synaptic components of the neuromuscular junction (NMJ) are involved. To search for candidate proteins implicated in this degenerative process, researchers have studied the Drosophila larval NMJ and find that the cytoskeleton-associated protein, adducin, is ideally placed to regulate synaptic contacts. By controlling the levels of synaptic proteins, adducin can de-stabilize synaptic contacts. Interestingly, elevated levels of phosphorylated adducin have been reported in ALS patients and in a mouse model of the disease. Adducin is regulated by phosphorylation through protein kinase C (PKC), some isoforms of which exhibit Ca2+-dependence, raising the possibility that changes in intracellular Ca2+ might alter PKC activation and secondarily influence adducin phosphorylation. Furthermore, adducin has interactions with the alpha subunit of the Na+/K+-ATPase. Thus, the phosphorylation of adducin may secondarily influence synaptic stability at the NMJ and so influence pre- and post-synaptic integrity at the NMJ in ALS.
Collapse
Affiliation(s)
- Charles Krieger
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University Burnaby, BC, Canada
| | - Simon Ji Hau Wang
- Department of Biomedical Physiology and Kinesiology, Simon Fraser UniversityBurnaby, BC, Canada; Department of Molecular Biology and Biochemistry, Simon Fraser UniversityBurnaby, BC, Canada
| | - Soo Hyun Yoo
- Department of Biomedical Physiology and Kinesiology, Simon Fraser UniversityBurnaby, BC, Canada; Department of Molecular Biology and Biochemistry, Simon Fraser UniversityBurnaby, BC, Canada
| | - Nicholas Harden
- Department of Molecular Biology and Biochemistry, Simon Fraser University Burnaby, BC, Canada
| |
Collapse
|
210
|
Transcriptional analysis reveals distinct subtypes in amyotrophic lateral sclerosis: implications for personalized therapy. Future Med Chem 2016; 7:1335-59. [PMID: 26144267 DOI: 10.4155/fmc.15.60] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is an incurable disease, caused by the loss of the upper and lower motor neurons. The lack of therapeutic progress is mainly due to the insufficient understanding of complexity and heterogeneity underlying the pathogenic mechanisms of ALS. Recently, we analyzed whole-genome expression profiles of motor cortex of sporadic ALS patients, classifying them into two subgroups characterized by differentially expressed genes and pathways. Some of the deregulated genes encode proteins, which are primary targets of drugs currently in preclinical or clinical studies for several clinical conditions, including neurodegenerative diseases. In this review, we discuss in-depth the potential role of these candidate targets in ALS pathogenesis, highlighting their possible relevance for personalized ALS treatments.
Collapse
|
211
|
Gluska S, Chein M, Rotem N, Ionescu A, Perlson E. Tracking Quantum-Dot labeled neurotropic factors transport along primary neuronal axons in compartmental microfluidic chambers. Methods Cell Biol 2016; 131:365-87. [DOI: 10.1016/bs.mcb.2015.06.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
|
212
|
Ishibashi F, Kojima R, Taniguchi M, Kosaka A, Uetake H, Tavakoli M. The Expanded Bead Size of Corneal C-Nerve Fibers Visualized by Corneal Confocal Microscopy Is Associated with Slow Conduction Velocity of the Peripheral Nerves in Patients with Type 2 Diabetes Mellitus. J Diabetes Res 2016; 2016:3653459. [PMID: 27563679 PMCID: PMC4987467 DOI: 10.1155/2016/3653459] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2016] [Revised: 06/09/2016] [Accepted: 06/19/2016] [Indexed: 12/28/2022] Open
Abstract
This study aims to establish the corneal nerve fiber (CNF) morphological alterations in a large cohort of type 2 diabetic patients and to investigate the association between the bead size, a novel parameter representing composite of accumulated mitochondria, glycogen particles, and vesicles in CNF, and the neurophysiological dysfunctions of the peripheral nerves. 162 type 2 diabetic patients and 45 healthy control subjects were studied in detail with a battery of clinical and neurological examinations and corneal confocal microscopy. Compared with controls, patients had abnormal CNF parameters. In particular the patients had reduced density and length of CNF and beading frequency and increased bead size. Alterations in CNF parameters were significant even in patients without neuropathy. The HbA1c levels were tightly associated with the bead size, which was inversely related to the motor and sensory nerve conduction velocity (NCV) and to the distal latency period of the median nerve positively. The CNF density and length positively correlated with the NCV and amplitude. The hyperglycemia-induced expansion of beads in CNF might be a predictor of slow NCV in peripheral nerves in type 2 diabetic patients.
Collapse
Affiliation(s)
- Fukashi Ishibashi
- Ishibashi Clinic, 1-9-41-2 Kushido, Hatsukaichi, Hiroshima 738-0033, Japan
- *Fukashi Ishibashi: and
| | - Rie Kojima
- Ishibashi Clinic, 1-9-41-2 Kushido, Hatsukaichi, Hiroshima 738-0033, Japan
| | - Miki Taniguchi
- Ishibashi Clinic, 1-9-41-2 Kushido, Hatsukaichi, Hiroshima 738-0033, Japan
| | - Aiko Kosaka
- Ishibashi Clinic, 1-9-41-2 Kushido, Hatsukaichi, Hiroshima 738-0033, Japan
| | - Harumi Uetake
- Ishibashi Clinic, 1-9-41-2 Kushido, Hatsukaichi, Hiroshima 738-0033, Japan
| | - Mitra Tavakoli
- Centre for Endocrinology and Diabetes, Institute of Human Development, University of Manchester, 46 Grafton Street, Manchester M13 9NT, UK
- University of Exeter Medical School, St Luke's Campus, South Cloisters, Exeter EX1 2LU, UK
- *Mitra Tavakoli:
| |
Collapse
|
213
|
Chowdary PD, Che DL, Kaplan L, Chen O, Pu K, Bawendi M, Cui B. Nanoparticle-assisted optical tethering of endosomes reveals the cooperative function of dyneins in retrograde axonal transport. Sci Rep 2015; 5:18059. [PMID: 26656461 PMCID: PMC4674899 DOI: 10.1038/srep18059] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 10/27/2015] [Indexed: 01/01/2023] Open
Abstract
Dynein-dependent transport of organelles from the axon terminals to the cell bodies is essential to the survival and function of neurons. However, quantitative knowledge of dyneins on axonal organelles and their collective function during this long-distance transport is lacking because current technologies to do such measurements are not applicable to neurons. Here, we report a new method termed nanoparticle-assisted optical tethering of endosomes (NOTE) that made it possible to study the cooperative mechanics of dyneins on retrograde axonal endosomes in live neurons. In this method, the opposing force from an elastic tether causes the endosomes to gradually stall under load and detach with a recoil velocity proportional to the dynein forces. These recoil velocities reveal that the axonal endosomes, despite their small size, can recruit up to 7 dyneins that function as independent mechanical units stochastically sharing load, which is vital for robust retrograde axonal transport. This study shows that NOTE, which relies on controlled generation of reactive oxygen species, is a viable method to manipulate small cellular cargos that are beyond the reach of current technology.
Collapse
Affiliation(s)
- Praveen D. Chowdary
- Department of Chemistry, Stanford University, 380 Roth Way, Stanford, CA 94305, USA
| | - Daphne L. Che
- Department of Chemistry, Stanford University, 380 Roth Way, Stanford, CA 94305, USA
| | - Luke Kaplan
- Department of Chemistry, Stanford University, 380 Roth Way, Stanford, CA 94305, USA
| | - Ou Chen
- Department of Chemistry, Massachussets Institute of Technology, 77 Massachussets Ave, Cambridge, MA 02139, USA
| | - Kanyi Pu
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, N1.3, B2-05, Singapore 637459
| | - Moungi Bawendi
- Department of Chemistry, Massachussets Institute of Technology, 77 Massachussets Ave, Cambridge, MA 02139, USA
| | - Bianxiao Cui
- Department of Chemistry, Stanford University, 380 Roth Way, Stanford, CA 94305, USA
| |
Collapse
|
214
|
Song B, Liu J, Feng X, Wei L, Shao L. A review on potential neurotoxicity of titanium dioxide nanoparticles. NANOSCALE RESEARCH LETTERS 2015; 10:1042. [PMID: 26306536 PMCID: PMC4549355 DOI: 10.1186/s11671-015-1042-9] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 07/27/2015] [Indexed: 05/24/2023]
Abstract
As the rapid development of nanotechnology in the past three decades, titanium dioxide nanoparticles (TiO2 NPs), for their peculiar physicochemical properties, are widely applied in consumer products, food additives, cosmetics, drug carriers, and so on. However, little is known about their potential exposure and neurotoxic effects. Once NPs are unintentionally exposed to human beings, they could be absorbed, and then accumulated in the brain regions by passing through the blood-brain barrier (BBB) or through the nose-to-brain pathway, potentially leading to dysfunctions of central nerve system (CNS). Besides, NPs may affect the brain development of embryo by crossing the placental barrier. A few in vivo and in vitro researches have demonstrated that the morphology and function of neuronal or glial cells could be impaired by TiO2 NPs which might induce cell necrosis. Cellular components, such as mitochondrial, lysosome, and cytoskeleton, could also be influenced as well. The recognition ability, spatial memory, and learning ability of TiO2 NPs-treated rodents were significantly impaired, which meant that accumulation of TiO2 NPs in the brain could lead to neurodegeneration. However, conclusions obtained from those studies were not consistent with each other as researchers may choose different experimental parameters, including administration ways, dosage, size, and crystal structure of TiO2 NPs. Therefore, in order to fully understand the potential risks of TiO2 NPs to brain health, figure out research areas where further studies are required, and improve its bio-safety for applications in the near future, how TiO2 NPs interact with the brain is investigated in this review by summarizing the current researches on neurotoxicity induced by TiO2 NPs.
Collapse
Affiliation(s)
- Bin Song
- />Guizhou Provincial People’s Hospital, Guiyang, 550002 China
- />Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China
| | - Jia Liu
- />Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China
| | - Xiaoli Feng
- />Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China
| | - Limin Wei
- />Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China
| | - Longquan Shao
- />Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China
| |
Collapse
|
215
|
Gershoni-Emek N, Mazza A, Chein M, Gradus-Pery T, Xiang X, Li KW, Sharan R, Perlson E. Proteomic Analysis of Dynein-Interacting Proteins in Amyotrophic Lateral Sclerosis Synaptosomes Reveals Alterations in the RNA-Binding Protein Staufen1. Mol Cell Proteomics 2015; 15:506-22. [PMID: 26598648 DOI: 10.1074/mcp.m115.049965] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Indexed: 12/12/2022] Open
Abstract
Synapse disruption takes place in many neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). However, the mechanistic understanding of this process is still limited. We set out to study a possible role for dynein in synapse integrity. Cytoplasmic dynein is a multisubunit intracellular molecule responsible for diverse cellular functions, including long-distance transport of vesicles, organelles, and signaling factors toward the cell center. A less well-characterized role dynein may play is the spatial clustering and anchoring of various factors including mRNAs in distinct cellular domains such as the neuronal synapse. Here, in order to gain insight into dynein functions in synapse integrity and disruption, we performed a screen for novel dynein interactors at the synapse. Dynein immunoprecipitation from synaptic fractions of the ALS model mSOD1(G93A) and wild-type controls, followed by mass spectrometry analysis on synaptic fractions of the ALS model mSOD1(G93A) and wild-type controls, was performed. Using advanced network analysis, we identified Staufen1, an RNA-binding protein required for the transport and localization of neuronal RNAs, as a major mediator of dynein interactions via its interaction with protein phosphatase 1-beta (PP1B). Both in vitro and in vivo validation assays demonstrate the interactions of Staufen1 and PP1B with dynein, and their colocalization with synaptic markers was altered as a result of two separate ALS-linked mutations: mSOD1(G93A) and TDP43(A315T). Taken together, we suggest a model in which dynein's interaction with Staufen1 regulates mRNA localization along the axon and the synapses, and alterations in this process may correlate with synapse disruption and ALS toxicity.
Collapse
Affiliation(s)
- Noga Gershoni-Emek
- From the ‡Sagol School of Neuroscience and Department of Physiology and Pharmacology, Sackler School of Medicine and
| | - Arnon Mazza
- §Blavatnik School of Computer Science, Tel Aviv University, Israel
| | - Michael Chein
- From the ‡Sagol School of Neuroscience and Department of Physiology and Pharmacology, Sackler School of Medicine and
| | - Tal Gradus-Pery
- From the ‡Sagol School of Neuroscience and Department of Physiology and Pharmacology, Sackler School of Medicine and
| | - Xin Xiang
- ¶Department of Biochemistry and Molecular Biology, the Uniformed Services University of Health Sciences, Bethesda, MD
| | - Ka Wan Li
- ‖Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU University, Amsterdam, the Netherlands
| | - Roded Sharan
- §Blavatnik School of Computer Science, Tel Aviv University, Israel
| | - Eran Perlson
- From the ‡Sagol School of Neuroscience and Department of Physiology and Pharmacology, Sackler School of Medicine and
| |
Collapse
|
216
|
Kaus A, Sareen D. ALS Patient Stem Cells for Unveiling Disease Signatures of Motoneuron Susceptibility: Perspectives on the Deadly Mitochondria, ER Stress and Calcium Triad. Front Cell Neurosci 2015; 9:448. [PMID: 26635528 PMCID: PMC4652136 DOI: 10.3389/fncel.2015.00448] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 11/02/2015] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a largely sporadic progressive neurodegenerative disease affecting upper and lower motoneurons (MNs) whose specific etiology is incompletely understood. Mutations in superoxide dismutase-1 (SOD1), TAR DNA-binding protein 43 (TARDBP/TDP-43) and C9orf72, have been identified in subsets of familial and sporadic patients. Key associated molecular and neuropathological features include ubiquitinated TDP-43 inclusions, stress granules, aggregated dipeptide proteins from mutant C9orf72 transcripts, altered mitochondrial ultrastructure, dysregulated calcium homeostasis, oxidative and endoplasmic reticulum (ER) stress, and an unfolded protein response (UPR). Such impairments have been documented in ALS animal models; however, whether these mechanisms are initiating factors or later consequential events leading to MN vulnerability in ALS patients is debatable. Human induced pluripotent stem cells (iPSCs) are a valuable tool that could resolve this “chicken or egg” causality dilemma. Relevant systems for probing pathophysiologically affected cells from large numbers of ALS patients and discovering phenotypic disease signatures of early MN susceptibility are described. Performing unbiased ‘OMICS and high-throughput screening in relevant neural cells from a cohort of ALS patient iPSCs, and rescuing mitochondrial and ER stress impairments, can identify targeted therapeutics for increasing MN longevity in ALS.
Collapse
Affiliation(s)
- Anjoscha Kaus
- Board of Governors-Regenerative Medicine Institute, Cedars-Sinai Medical Center Los Angeles, CA, USA ; Department of Biomedical Sciences, Cedars-Sinai Medical Center Los Angeles, CA, USA
| | - Dhruv Sareen
- Board of Governors-Regenerative Medicine Institute, Cedars-Sinai Medical Center Los Angeles, CA, USA ; Department of Biomedical Sciences, Cedars-Sinai Medical Center Los Angeles, CA, USA ; iPSC Core, The David and Janet Polak Stem Cell Laboratory, Cedars-Sinai Medical Center Los Angeles, CA, USA
| |
Collapse
|
217
|
Adalbert R, Coleman MP. Review: Axon pathology in age-related neurodegenerative disorders. Neuropathol Appl Neurobiol 2015; 39:90-108. [PMID: 23046254 DOI: 10.1111/j.1365-2990.2012.01308.x] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2012] [Accepted: 09/24/2012] [Indexed: 12/12/2022]
Abstract
'Dying back' axon degeneration is a prominent feature of many age-related neurodegenerative disorders and is widespread in normal ageing. Although the mechanisms of disease- and age-related losses may differ, both contribute to symptoms. Here, we review recent advances in understanding axon pathology in age-related neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis and glaucoma. In particular, we highlight the importance of axonal transport, autophagy, traumatic brain injury and mitochondrial quality control. We then place these disease mechanisms in the context of changes to axons and dendrites that occur during normal ageing. We discuss what makes ageing such an important risk factor for many neurodegenerative disorders and conclude that the processes of normal ageing and disease combine at the molecular, cellular or systems levels in a range of disorders to produce symptoms. Pathology identical to disease also occurs at the cellular level in most elderly individuals. Thus, normal ageing and age-related disease are inextricably linked and the term 'healthy ageing' downplays the important contributions of cellular pathology. For a full understanding of normal ageing or age-related disease we must study both processes.
Collapse
Affiliation(s)
- R Adalbert
- Signalling Programme, The Babraham Institute, Babraham, Cambridge, UK
| | - M P Coleman
- Signalling Programme, The Babraham Institute, Babraham, Cambridge, UK
| |
Collapse
|
218
|
Miller KE, Liu XA, Puthanveettil SV. Automated measurement of fast mitochondrial transport in neurons. Front Cell Neurosci 2015; 9:435. [PMID: 26578890 PMCID: PMC4630299 DOI: 10.3389/fncel.2015.00435] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 10/16/2015] [Indexed: 01/20/2023] Open
Abstract
There is growing recognition that fast mitochondrial transport in neurons is disrupted in multiple neurological diseases and psychiatric disorders. However, a major constraint in identifying novel therapeutics based on mitochondrial transport is that the large-scale analysis of fast transport is time consuming. Here we describe methodologies for the automated analysis of fast mitochondrial transport from data acquired using a robotic microscope. We focused on addressing questions of measurement precision, speed, reliably, workflow ease, statistical processing, and presentation. We used optical flow and particle tracking algorithms, implemented in ImageJ, to measure mitochondrial movement in primary cultured cortical and hippocampal neurons. With it, we are able to generate complete descriptions of movement profiles in an automated fashion of hundreds of thousands of mitochondria with a processing time of approximately one hour. We describe the calibration of the parameters of the tracking algorithms and demonstrate that they are capable of measuring the fast transport of a single mitochondrion. We then show that the methods are capable of reliably measuring the inhibition of fast mitochondria transport induced by the disruption of microtubules with the drug nocodazole in both hippocampal and cortical neurons. This work lays the foundation for future large-scale screens designed to identify compounds that modulate mitochondrial motility.
Collapse
Affiliation(s)
- Kyle E Miller
- Department of Integrative Biology, Michigan State University East Lansing, MI, USA
| | - Xin-An Liu
- Department of Neuroscience, The Scripps Research Institute, Scripps Florida Jupiter, FL, USA
| | | |
Collapse
|
219
|
Che DL, Chowdary PD, Cui B. A close look at axonal transport: Cargos slow down when crossing stationary organelles. Neurosci Lett 2015; 610:110-6. [PMID: 26528790 DOI: 10.1016/j.neulet.2015.10.066] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 10/23/2015] [Accepted: 10/26/2015] [Indexed: 01/11/2023]
Abstract
The bidirectional transport of cargos along the thin axon is fundamental for the structure, function and survival of neurons. Defective axonal transport has been linked to the mechanism of neurodegenerative diseases. In this paper, we study the effect of the local axonal environment to cargo transport behavior in neurons. Using dual-color fluorescence imaging in microfluidic neuronal devices, we quantify the transport dynamics of cargos when crossing stationary organelles such as non-moving endosomes and stationary mitochondria in the axon. We show that the axonal cargos tend to slow down, or pause transiently within the vicinity of stationary organelles. The slow-down effect is observed in both retrograde and anterograde transport directions of three different cargos (TrkA, lysosomes and TrkB). Our results agree with the hypothesis that bulky axonal structures can pose as steric hindrance for axonal transport. However, the results do not rule out the possibility that cellular mechanisms causing stationary organelles are also responsible for the delay in moving cargos at the same locations.
Collapse
Affiliation(s)
- Daphne L Che
- Department of Chemistry, Stanford University, Stanford, CA 94305, United States
| | - Praveen D Chowdary
- Department of Chemistry, Stanford University, Stanford, CA 94305, United States
| | - Bianxiao Cui
- Department of Chemistry, Stanford University, Stanford, CA 94305, United States.
| |
Collapse
|
220
|
Proteomics in Traditional Chinese Medicine with an Emphasis on Alzheimer's Disease. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:393510. [PMID: 26557146 PMCID: PMC4628675 DOI: 10.1155/2015/393510] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Accepted: 07/27/2015] [Indexed: 12/12/2022]
Abstract
In recent years, there has been an increasing worldwide interest in traditional Chinese medicine (TCM). This increasing demand for TCM needs to be accompanied by a deeper understanding of the mechanisms of action of TCM-based therapy. However, TCM is often described as a concept of Chinese philosophy, which is incomprehensible for Western medical society, thereby creating a gap between TCM and Western medicine (WM). In order to meet this challenge, TCM research has applied proteomics technologies for exploring the mechanisms of action of TCM treatment. Proteomics enables TCM researchers to oversee various pathways that are affected by treatment, as well as the dynamics of their interactions with one another. This review discusses the utility of comparative proteomics to better understand how TCM treatment may be used as a complementary therapy for Alzheimer's disease (AD). Additionally, we review the data from comparative AD-related TCM proteomics studies and establish the relevance of the data with available AD hypotheses, most notably regarding the ubiquitin proteasome system (UPS).
Collapse
|
221
|
Li H, Custer SK, Gilson T, Hao LT, Beattie CE, Androphy EJ. α-COP binding to the survival motor neuron protein SMN is required for neuronal process outgrowth. Hum Mol Genet 2015; 24:7295-307. [PMID: 26464491 DOI: 10.1093/hmg/ddv428] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Accepted: 10/06/2015] [Indexed: 01/30/2023] Open
Abstract
Spinal muscular atrophy (SMA), a heritable neurodegenerative disease, results from insufficient levels of the survival motor neuron (SMN) protein. α-COP binds to SMN, linking the COPI vesicular transport pathway to SMA. Reduced levels of α-COP restricted development of neuronal processes in NSC-34 cells and primary cortical neurons. Remarkably, heterologous expression of human α-COP restored normal neurite length and morphology in SMN-depleted NSC-34 cells in vitro and zebrafish motor neurons in vivo. We identified single amino acid mutants of α-COP that selectively abrogate SMN binding, retain COPI-mediated Golgi-ER trafficking functionality, but were unable to support neurite outgrowth in cellular and zebrafish models of SMA. Taken together, these demonstrate the functional role of COPI association with the SMN protein in neuronal development.
Collapse
Affiliation(s)
- Hongxia Li
- Department of Dermatology, Indiana University School of Medicine, Indianapolis, IN 46202, USA and
| | - Sara K Custer
- Department of Dermatology, Indiana University School of Medicine, Indianapolis, IN 46202, USA and
| | - Timra Gilson
- Department of Dermatology, Indiana University School of Medicine, Indianapolis, IN 46202, USA and
| | - Le Thi Hao
- Department of Neuroscience, The Ohio State University, Columbus, OH 43210, USA
| | - Christine E Beattie
- Department of Neuroscience, The Ohio State University, Columbus, OH 43210, USA
| | - Elliot J Androphy
- Department of Dermatology, Indiana University School of Medicine, Indianapolis, IN 46202, USA and
| |
Collapse
|
222
|
Rodríguez-Martín T, Pooler AM, Lau DHW, Mórotz GM, De Vos KJ, Gilley J, Coleman MP, Hanger DP. Reduced number of axonal mitochondria and tau hypophosphorylation in mouse P301L tau knockin neurons. Neurobiol Dis 2015; 85:1-10. [PMID: 26459111 PMCID: PMC4684147 DOI: 10.1016/j.nbd.2015.10.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 09/28/2015] [Accepted: 10/08/2015] [Indexed: 12/12/2022] Open
Abstract
Expression of the frontotemporal dementia-related tau mutation, P301L, at physiological levels in adult mouse brain (KI-P301L mice) results in overt hypophosphorylation of tau and age-dependent alterations in axonal mitochondrial transport in peripheral nerves. To determine the effects of P301L tau expression in the central nervous system, we examined the kinetics of mitochondrial axonal transport and tau phosphorylation in primary cortical neurons from P301L knock-in (KI-P301L) mice. We observed a significant 50% reduction in the number of mitochondria in the axons of cortical neurons cultured from KI-P301L mice compared to wild-type neurons. Expression of murine P301L tau did not change the speed, direction of travel or likelihood of movement of mitochondria. Notably, the angle that defines the orientation of the mitochondria in the axon, and the volume of individual moving mitochondria, were significantly increased in neurons expressing P301L tau. We found that murine tau phosphorylation in KI-P301L mouse neurons was diminished and the ability of P301L tau to bind to microtubules was also reduced compared to tau in wild-type neurons. The P301L mutation did not influence the ability of murine tau to associate with membranes in cortical neurons or in adult mouse brain. We conclude that P301L tau is associated with mitochondrial changes and causes an early reduction in murine tau phosphorylation in neurons coupled with impaired microtubule binding of tau. These results support the association of mutant tau with detrimental effects on mitochondria and will be of significance for the pathogenesis of tauopathies. Expression of P301L tau reduces the number of axonal mitochondria in mice. Motile mitochondria exhibit increased volume in axons of neurons with P301L tau. P301L tau expressed in knockin mice is hypophosphorylated. The P301L tau mutation impairs microtubule binding but does not affect tau membrane localization.
Collapse
Affiliation(s)
- Teresa Rodríguez-Martín
- King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, London, SE5 9NU, UK.
| | - Amy M Pooler
- King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, London, SE5 9NU, UK.
| | - Dawn H W Lau
- King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, London, SE5 9NU, UK.
| | - Gábor M Mórotz
- King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, London, SE5 9NU, UK.
| | - Kurt J De Vos
- King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, London, SE5 9NU, UK.
| | - Jonathan Gilley
- Signalling Programme, The Babraham Institute, Cambridge CB22 3AT, UK.
| | - Michael P Coleman
- Signalling Programme, The Babraham Institute, Cambridge CB22 3AT, UK.
| | - Diane P Hanger
- King's College London, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Department of Basic and Clinical Neuroscience, London, SE5 9NU, UK.
| |
Collapse
|
223
|
Allen SP, Duffy LM, Shaw PJ, Grierson AJ. Altered age-related changes in bioenergetic properties and mitochondrial morphology in fibroblasts from sporadic amyotrophic lateral sclerosis patients. Neurobiol Aging 2015; 36:2893-903. [DOI: 10.1016/j.neurobiolaging.2015.07.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 06/19/2015] [Accepted: 07/01/2015] [Indexed: 12/11/2022]
|
224
|
Arias CI, Siri SO, Conde C. Involvement of SARA in Axon and Dendrite Growth. PLoS One 2015; 10:e0138792. [PMID: 26405814 PMCID: PMC4583221 DOI: 10.1371/journal.pone.0138792] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 09/03/2015] [Indexed: 11/19/2022] Open
Abstract
SARA (Smad Anchor for Receptor Activation) plays a crucial role in Rab5-mediated endocytosis in cell lines localizing to early endosomes where it regulates morphology and function. Here, we analyzed the role of SARA during neuronal development and tested whether it functions as a regulator of endocytic trafficking of selected axonal and membrane proteins. Suppression of SARA perturbs the appearance of juxtanuclear endocytic recycling compartments and the neurons show long axons with large growth cones. Furthermore, surface distribution of the cell adhesion molecule L1 in axons and the fusion of vesicles containing transferring receptor (TfR) in dendrites were increased in neurons where SARA was silenced. Conversely, SARA overexpression generated large early endosomes and reduced neurite outgrowth. Taken together, our findings suggest a significant contribution of SARA to key aspects of neuronal development, including neurite formation.
Collapse
Affiliation(s)
| | - Sebastián Omar Siri
- Laboratorio Neurobiología, INIMEC-CONICET, Córdoba, Argentina
- Universidad Nacional de Córdoba, Córdoba, Argentina
- Instituto Universitario de Ciencias Biomédicas de Córdoba, Córdoba, Argentina
| | - Cecilia Conde
- Laboratorio Neurobiología, INIMEC-CONICET, Córdoba, Argentina
- Universidad Nacional de Córdoba, Córdoba, Argentina
- Instituto Universitario de Ciencias Biomédicas de Córdoba, Córdoba, Argentina
| |
Collapse
|
225
|
Dubey J, Ratnakaran N, Koushika SP. Neurodegeneration and microtubule dynamics: death by a thousand cuts. Front Cell Neurosci 2015; 9:343. [PMID: 26441521 PMCID: PMC4563776 DOI: 10.3389/fncel.2015.00343] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Accepted: 08/18/2015] [Indexed: 12/11/2022] Open
Abstract
Microtubules form important cytoskeletal structures that play a role in establishing and maintaining neuronal polarity, regulating neuronal morphology, transporting cargo, and scaffolding signaling molecules to form signaling hubs. Within a neuronal cell, microtubules are found to have variable lengths and can be both stable and dynamic. Microtubule associated proteins, post-translational modifications of tubulin subunits, microtubule severing enzymes, and signaling molecules are all known to influence both stable and dynamic pools of microtubules. Microtubule dynamics, the process of interconversion between stable and dynamic pools, and the proportions of these two pools have the potential to influence a wide variety of cellular processes. Reduced microtubule stability has been observed in several neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), Amyotrophic Lateral Sclerosis (ALS), and tauopathies like Progressive Supranuclear Palsy. Hyperstable microtubules, as seen in Hereditary Spastic Paraplegia (HSP), also lead to neurodegeneration. Therefore, the ratio of stable and dynamic microtubules is likely to be important for neuronal function and perturbation in microtubule dynamics might contribute to disease progression.
Collapse
Affiliation(s)
- Jyoti Dubey
- Department of Biological Sciences, Tata Institute of Fundamental Research Mumbai, India ; InStem Bangalore, India
| | - Neena Ratnakaran
- Department of Biological Sciences, Tata Institute of Fundamental Research Mumbai, India
| | - Sandhya P Koushika
- Department of Biological Sciences, Tata Institute of Fundamental Research Mumbai, India
| |
Collapse
|
226
|
Beck K, Ehmann N, Andlauer TFM, Ljaschenko D, Strecker K, Fischer M, Kittel RJ, Raabe T. Loss of the Coffin-Lowry syndrome-associated gene RSK2 alters ERK activity, synaptic function and axonal transport in Drosophila motoneurons. Dis Model Mech 2015; 8:1389-400. [PMID: 26398944 PMCID: PMC4631788 DOI: 10.1242/dmm.021246] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 08/27/2015] [Indexed: 01/06/2023] Open
Abstract
Plastic changes in synaptic properties are considered as fundamental for adaptive behaviors. Extracellular-signal-regulated kinase (ERK)-mediated signaling has been implicated in regulation of synaptic plasticity. Ribosomal S6 kinase 2 (RSK2) acts as a regulator and downstream effector of ERK. In the brain, RSK2 is predominantly expressed in regions required for learning and memory. Loss-of-function mutations in human RSK2 cause Coffin-Lowry syndrome, which is characterized by severe mental retardation and low IQ scores in affected males. Knockout of RSK2 in mice or the RSK ortholog in Drosophila results in a variety of learning and memory defects. However, overall brain structure in these animals is not affected, leaving open the question of the pathophysiological consequences. Using the fly neuromuscular system as a model for excitatory glutamatergic synapses, we show that removal of RSK function causes distinct defects in motoneurons and at the neuromuscular junction. Based on histochemical and electrophysiological analyses, we conclude that RSK is required for normal synaptic morphology and function. Furthermore, loss of RSK function interferes with ERK signaling at different levels. Elevated ERK activity was evident in the somata of motoneurons, whereas decreased ERK activity was observed in axons and the presynapse. In addition, we uncovered a novel function of RSK in anterograde axonal transport. Our results emphasize the importance of fine-tuning ERK activity in neuronal processes underlying higher brain functions. In this context, RSK acts as a modulator of ERK signaling.
Collapse
Affiliation(s)
- Katherina Beck
- University of Würzburg, Institute of Medical Radiation and Cell Research, Versbacherstraße 5, Würzburg D-97078, Germany
| | - Nadine Ehmann
- University of Würzburg, Institute of Physiology, Department of Neurophysiology, Röntgenring 9, Würzburg D-97070, Germany
| | - Till F M Andlauer
- University of Würzburg, Rudolf Virchow Center, DFG Research Center for Experimental Biomedicine, Josef-Schneider-Straße 2, Würzburg D-97080, Germany Freie Universität Berlin, Institute of Biology, Takusstraße 6, Berlin D-14195, Germany Max Planck Institute of Colloidals and Interfaces, Am Mühlenberg 1, Potsdam D-14476, Germany
| | - Dmitrij Ljaschenko
- University of Würzburg, Institute of Physiology, Department of Neurophysiology, Röntgenring 9, Würzburg D-97070, Germany
| | - Katrin Strecker
- University of Würzburg, Institute of Medical Radiation and Cell Research, Versbacherstraße 5, Würzburg D-97078, Germany
| | - Matthias Fischer
- University Hospital Würzburg, Department of Psychiatry, Psychosomatics and Psychotherapy, Füchsleinstraße 15, Würzburg 97080, Germany
| | - Robert J Kittel
- University of Würzburg, Institute of Physiology, Department of Neurophysiology, Röntgenring 9, Würzburg D-97070, Germany
| | - Thomas Raabe
- University of Würzburg, Institute of Medical Radiation and Cell Research, Versbacherstraße 5, Würzburg D-97078, Germany
| |
Collapse
|
227
|
Edwards SL, Morrison LM, Yorks RM, Hoover CM, Boominathan S, Miller KG. UNC-16 (JIP3) Acts Through Synapse-Assembly Proteins to Inhibit the Active Transport of Cell Soma Organelles to Caenorhabditis elegans Motor Neuron Axons. Genetics 2015; 201:117-41. [PMID: 26354976 PMCID: PMC4566257 DOI: 10.1534/genetics.115.177345] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 06/24/2015] [Indexed: 12/31/2022] Open
Abstract
The conserved protein UNC-16 (JIP3) inhibits the active transport of some cell soma organelles, such as lysosomes, early endosomes, and Golgi, to the synaptic region of axons. However, little is known about UNC-16's organelle transport regulatory function, which is distinct from its Kinesin-1 adaptor function. We used an unc-16 suppressor screen in Caenorhabditis elegans to discover that UNC-16 acts through CDK-5 (Cdk5) and two conserved synapse assembly proteins: SAD-1 (SAD-A Kinase), and SYD-2 (Liprin-α). Genetic analysis of all combinations of double and triple mutants in unc-16(+) and unc-16(-) backgrounds showed that the three proteins (CDK-5, SAD-1, and SYD-2) are all part of the same organelle transport regulatory system, which we named the CSS system based on its founder proteins. Further genetic analysis revealed roles for SYD-1 (another synapse assembly protein) and STRADα (a SAD-1-interacting protein) in the CSS system. In an unc-16(-) background, loss of the CSS system improved the sluggish locomotion of unc-16 mutants, inhibited axonal lysosome accumulation, and led to the dynein-dependent accumulation of lysosomes in dendrites. Time-lapse imaging of lysosomes in CSS system mutants in unc-16(+) and unc-16(-) backgrounds revealed active transport defects consistent with the steady-state distributions of lysosomes. UNC-16 also uses the CSS system to regulate the distribution of early endosomes in neurons and, to a lesser extent, Golgi. The data reveal a new and unprecedented role for synapse assembly proteins, acting as part of the newly defined CSS system, in mediating UNC-16's organelle transport regulatory function.
Collapse
Affiliation(s)
- Stacey L Edwards
- Genetic Models of Disease Laboratory, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104
| | - Logan M Morrison
- Genetic Models of Disease Laboratory, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104
| | - Rosalina M Yorks
- Genetic Models of Disease Laboratory, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104
| | - Christopher M Hoover
- Genetic Models of Disease Laboratory, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104
| | - Soorajnath Boominathan
- Genetic Models of Disease Laboratory, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104
| | - Kenneth G Miller
- Genetic Models of Disease Laboratory, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma 73104
| |
Collapse
|
228
|
Stratmann K, Heinsen H, Korf HW, Del Turco D, Ghebremedhin E, Seidel K, Bouzrou M, Grinberg LT, Bohl J, Wharton SB, den Dunnen W, Rüb U. Precortical Phase of Alzheimer's Disease (AD)-Related Tau Cytoskeletal Pathology. Brain Pathol 2015; 26:371-86. [PMID: 26193084 DOI: 10.1111/bpa.12289] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 07/13/2015] [Indexed: 01/01/2023] Open
Abstract
Alzheimer's disease (AD) represents the most frequent progressive neuropsychiatric disorder worldwide leading to dementia. We systematically investigated the presence and extent of the AD-related cytoskeletal pathology in serial thick tissue sections through all subcortical brain nuclei that send efferent projections to the transentorhinal and entorhinal regions in three individuals with Braak and Braak AD stage 0 cortical cytoskeletal pathology and fourteen individuals with Braak and Braak AD stage I cortical cytoskeletal pathology by means of immunostainings with the anti-tau antibody AT8. These investigations revealed consistent AT8 immunoreactive tau cytoskeletal pathology in a subset of these subcortical nuclei in the Braak and Braak AD stage 0 individuals and in all of these subcortical nuclei in the Braak and Braak AD stage I individuals. The widespread affection of the subcortical nuclei in Braak and Braak AD stage I shows that the extent of the early subcortical tau cytoskeletal pathology has been considerably underestimated previously. In addition, our novel findings support the concept that subcortical nuclei become already affected during an early 'pre-cortical' evolutional phase before the first AD-related cytoskeletal changes occur in the mediobasal temporal lobe (i.e. allocortical transentorhinal and entorhinal regions). The very early involved subcortical brain regions may represent the origin of the AD-related tau cytoskeletal pathology, from where the neuronal cytoskeletal pathology takes an ascending course toward the secondarily affected allocortex and spreads transneuronally along anatomical pathways in predictable sequences.
Collapse
Affiliation(s)
- Katharina Stratmann
- Dr. Senckenbergisches Chronomedizinisches Institut, Goethe University, Frankfurt/Main, Germany
| | - Helmut Heinsen
- Morphological Brain Research Unit, Psychiatric Clinic, Julius Maximilians University Würzburg, Würzburg, Germany
| | - Horst-Werner Korf
- Dr. Senckenbergisches Chronomedizinisches Institut, Goethe University, Frankfurt/Main, Germany
| | - Domenico Del Turco
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University, Frankfurt/Main, Germany
| | - Estifanos Ghebremedhin
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University, Frankfurt/Main, Germany
| | - Kay Seidel
- Dr. Senckenbergisches Chronomedizinisches Institut, Goethe University, Frankfurt/Main, Germany
| | - Mohamed Bouzrou
- Dr. Senckenbergisches Chronomedizinisches Institut, Goethe University, Frankfurt/Main, Germany
| | - Lea T Grinberg
- Department of Neurology, Memory and Aging Center, University of California at San Francisco, San Francisco, CA.,Department of Pathology, University of Sao Paulo Medical School, Sao Paulo, Brazil
| | - Jürgen Bohl
- Neuropathology Division, University Clinic of Mainz, Mainz, Germany
| | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Wilfred den Dunnen
- Department of Pathology and Medical Biology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Udo Rüb
- Dr. Senckenbergisches Chronomedizinisches Institut, Goethe University, Frankfurt/Main, Germany
| |
Collapse
|
229
|
Scharrel L, Ma R, Schneider R, Jülicher F, Diez S. Multimotor transport in a system of active and inactive kinesin-1 motors. Biophys J 2015; 107:365-372. [PMID: 25028878 DOI: 10.1016/j.bpj.2014.06.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 05/28/2014] [Accepted: 06/03/2014] [Indexed: 10/25/2022] Open
Abstract
Long-range directional transport in cells is facilitated by microtubule-based motor proteins. One example is transport in a nerve cell, where small groups of motor proteins, such as kinesins and cytoplasmic dynein, work together to ensure the supply and clearance of cellular material along the axon. Defects in axonal transport have been linked to Alzheimer's and other neurodegenerative diseases. However, it is not known in detail how multimotor-based cargo transport is impaired if a fraction of the motors are defective. To mimic impaired multimotor transport in vitro, we performed gliding motility assays with varying fractions of active kinesin-1 motors and inactive kinesin-1 motor mutants. We found that impaired transport manifests in multiple motility regimes: 1), a fast-motility regime characterized by gliding at velocities close to the single-molecule velocity of the active motors; 2), a slow-motility regime characterized by gliding at close-to zero velocity or full stopping; and 3), a regime in which fast and slow motilities coexist. Notably, the transition from the fast to the slow regime occurred sharply at a threshold fraction of active motors. Based on single-motor parameters, we developed a stochastic model and a mean-field theoretical description that explain our experimental findings. Our results demonstrate that impaired multimotor transport mostly occurs in an either/or fashion: depending on the ratio of active to inactive motors, transport is either performed at close to full speed or is out of action.
Collapse
Affiliation(s)
- Lara Scharrel
- B CUBE - Center for Molecular Bioengineering, Technische Universität Dresden, Dresden, Germany; Max Planck Institute of Cell Biology and Genetics, Dresden, Germany
| | - Rui Ma
- Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
| | - René Schneider
- B CUBE - Center for Molecular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Frank Jülicher
- Max Planck Institute for the Physics of Complex Systems, Dresden, Germany.
| | - Stefan Diez
- B CUBE - Center for Molecular Bioengineering, Technische Universität Dresden, Dresden, Germany; Max Planck Institute of Cell Biology and Genetics, Dresden, Germany.
| |
Collapse
|
230
|
Abstract
Neurons are extremely polarized cells. Axon lengths often exceed the dimension of the neuronal cell body by several orders of magnitude. These extreme axonal lengths imply that neurons have mastered efficient mechanisms for long distance signaling between soma and synaptic terminal. These elaborate mechanisms are required for neuronal development and maintenance of the nervous system. Neurons can fine-tune long distance signaling through calcium wave propagation and bidirectional transport of proteins, vesicles, and mRNAs along microtubules. The signal transmission over extreme lengths also ensures that information about axon injury is communicated to the soma and allows for repair mechanisms to be engaged. This review focuses on the different mechanisms employed by neurons to signal over long axonal distances and how signals are interpreted in the soma, with an emphasis on proteomic studies. We also discuss how proteomic approaches could help further deciphering the signaling mechanisms operating over long distance in axons.
Collapse
Affiliation(s)
- Atsushi Saito
- From the ‡Department of Anatomy and Neurobiology, Washington University in St Louis, School of Medicine, St Louis, 63110, Missouri
| | - Valeria Cavalli
- From the ‡Department of Anatomy and Neurobiology, Washington University in St Louis, School of Medicine, St Louis, 63110, Missouri.
| |
Collapse
|
231
|
Aleng NA, Sung YY, MacRae TH, Abd Wahid ME. Non-Lethal Heat Shock of the Asian Green Mussel, Perna viridis, Promotes Hsp70 Synthesis, Induces Thermotolerance and Protects Against Vibrio Infection. PLoS One 2015; 10:e0135603. [PMID: 26288319 PMCID: PMC4546054 DOI: 10.1371/journal.pone.0135603] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Accepted: 07/24/2015] [Indexed: 11/25/2022] Open
Abstract
Mild heat stress promotes thermotolerance and protection against several different stresses in aquatic animals, consequences correlated with the accumulation of heat shock protein 70 (Hsp70). The purpose of this study was to determine if non-lethal heat shock (NLHS) of the Asian green mussel, Perna viridis, an aquatic species of commercial value, promoted the production of Hsp70 and enhanced its resistance to stresses. Initially, the LT50 and LHT for P. viridis were determined to be 42°C and 44°C, respectively, with no heat shock induced death of mussels at 40°C or less. Immunoprobing of western blots revealed augmentation of constitutive (PvHsp70-1) and inducible (PvHsp70-2) Hsp70 in tissue from adductor muscle, foot, gill and mantel of P. viridis exposed to 38°C for 30 min followed by 6 h recovery, NLHS conditions for this organism. Characterization by liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed that PvHsp70-1 and PvHsp70-2 respectively corresponded most closely to Hsp70 from P. viridis and Mytilus galloprovincialis. Priming of adult mussels with NLHS promoted thermotolerance and increased resistance to V. alginolyticus. The induction of Hsp70 in parallel with enhanced thermotolerance and improved protection against V. alginolyticus, suggests Hsp70 functions in P. viridis as a molecular chaperone and as a stimulator of the immune system.
Collapse
Affiliation(s)
- Nor Afiqah Aleng
- Institute of Marine Biotechnology, Universiti Malaysia Terengganu (UMT), 21030, Kuala Terengganu, Malaysia
| | - Yeong Yik Sung
- Institute of Marine Biotechnology, Universiti Malaysia Terengganu (UMT), 21030, Kuala Terengganu, Malaysia
- School of Fisheries and Aquaculture Sciences, Universiti Malaysia Terengganu (UMT), 21030, Kuala Terengganu, Malaysia
- * E-mail: (YYS); (MEAW)
| | - Thomas H. MacRae
- Department of Biology, Dalhousie University, Halifax, NS, B3H 4R2, Canada
| | - Mohd Effendy Abd Wahid
- Institute of Marine Biotechnology, Universiti Malaysia Terengganu (UMT), 21030, Kuala Terengganu, Malaysia
- School of Fisheries and Aquaculture Sciences, Universiti Malaysia Terengganu (UMT), 21030, Kuala Terengganu, Malaysia
- * E-mail: (YYS); (MEAW)
| |
Collapse
|
232
|
A Stochastic Multiscale Model That Explains the Segregation of Axonal Microtubules and Neurofilaments in Neurological Diseases. PLoS Comput Biol 2015; 11:e1004406. [PMID: 26285012 PMCID: PMC4540448 DOI: 10.1371/journal.pcbi.1004406] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 06/17/2015] [Indexed: 11/19/2022] Open
Abstract
The organization of the axonal cytoskeleton is a key determinant of the normal function of an axon, which is a long thin projection of a neuron. Under normal conditions two axonal cytoskeletal polymers, microtubules and neurofilaments, align longitudinally in axons and are interspersed in axonal cross-sections. However, in many neurotoxic and neurodegenerative disorders, microtubules and neurofilaments segregate apart from each other, with microtubules and membranous organelles clustered centrally and neurofilaments displaced to the periphery. This striking segregation precedes the abnormal and excessive neurofilament accumulation in these diseases, which in turn leads to focal axonal swellings. While neurofilament accumulation suggests an impairment of neurofilament transport along axons, the underlying mechanism of their segregation from microtubules remains poorly understood for over 30 years. To address this question, we developed a stochastic multiscale model for the cross-sectional distribution of microtubules and neurofilaments in axons. The model describes microtubules, neurofilaments and organelles as interacting particles in a 2D cross-section, and is built upon molecular processes that occur on a time scale of seconds or shorter. It incorporates the longitudinal transport of neurofilaments and organelles through this domain by allowing stochastic arrival and departure of these cargoes, and integrates the dynamic interactions of these cargoes with microtubules mediated by molecular motors. Simulations of the model demonstrate that organelles can pull nearby microtubules together, and in the absence of neurofilament transport, this mechanism gradually segregates microtubules from neurofilaments on a time scale of hours, similar to that observed in toxic neuropathies. This suggests that the microtubule-neurofilament segregation can be a consequence of the selective impairment of neurofilament transport. The model generates the experimentally testable prediction that the rate and extent of segregation will be dependent on the sizes of the moving organelles as well as the density of their traffic. The shape and function of axons is dependent on a dynamic system of microscopic intracellular protein polymers (microtubules, neurofilaments and microfilaments) that comprise the axonal cytoskeleton. Neurofilaments are cargoes of intracellular transport that move along microtubule tracks, and they accumulate abnormally in axons in many neurotoxic and neurodegenerative disorders. Intriguingly, it has been reported that neurofilaments and microtubules, which are normally interspersed in axonal cross-sections, often segregate apart from each other in these disorders, which is something that is never observed in healthy axons. Here we describe a stochastic multiscale computational model that explains the mechanism of this striking segregation and offers insights into the mechanism of neurofilament accumulation in disease.
Collapse
|
233
|
Kevenaar JT, Hoogenraad CC. The axonal cytoskeleton: from organization to function. Front Mol Neurosci 2015; 8:44. [PMID: 26321907 PMCID: PMC4536388 DOI: 10.3389/fnmol.2015.00044] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 07/31/2015] [Indexed: 01/20/2023] Open
Abstract
The axon is the single long fiber that extends from the neuron and transmits electrical signals away from the cell body. The neuronal cytoskeleton, composed of microtubules (MTs), actin filaments and neurofilaments, is not only required for axon formation and axonal transport but also provides the structural basis for several specialized axonal structures, such as the axon initial segment (AIS) and presynaptic boutons. Emerging evidence suggest that the unique cytoskeleton organization in the axon is essential for its structure and integrity. In addition, the increasing number of neurodevelopmental and neurodegenerative diseases linked to defect in actin- and microtubule-dependent processes emphasizes the importance of a properly regulated cytoskeleton for normal axonal functioning. Here, we provide an overview of the current understanding of actin and microtubule organization within the axon and discuss models for the functional role of the cytoskeleton at specialized axonal structures.
Collapse
Affiliation(s)
- Josta T. Kevenaar
- Cell Biology, Faculty of Science, Utrecht UniversityUtrecht, Netherlands
| | | |
Collapse
|
234
|
Audouard E, Van Hees L, Suain V, Yilmaz Z, Poncelet L, Leroy K, Brion JP. Motor deficit in a tauopathy model is induced by disturbances of axonal transport leading to dying-back degeneration and denervation of neuromuscular junctions. THE AMERICAN JOURNAL OF PATHOLOGY 2015; 185:2685-97. [PMID: 26272360 DOI: 10.1016/j.ajpath.2015.06.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 06/25/2015] [Accepted: 06/29/2015] [Indexed: 01/08/2023]
Abstract
Several neurodegenerative diseases are characterized by both cognitive and motor deficits associated with accumulation of tau aggregates in brain, brainstem, and spinal cord. The Tg30 murine tauopathy model expresses a human tau protein bearing two frontotemporal dementia with Parkinsonism linked to chromosome 17 pathogenic mutations and develops a severe motor deficit and tau aggregates in brain and spinal cord. To investigate the origin of this motor deficit, we analyzed the age-dependent innervation status of the neuromuscular junctions and mutant tau expression in Tg30 mice. The human transgenic tau was detected from postnatal day 7 onward in motoneurons, axons in the sciatic nerve, and axon terminals of the neuromuscular junctions. The development and maturation of neuromuscular junctions were not disrupted in Tg30 mice, but their maintenance was disturbed in adult Tg30 mice, resulting in a progressive and severe muscle denervation. This muscle denervation was associated with early electrophysiological signs of muscle spontaneous activities and histological signs of muscle degeneration. Early loss of synaptic vesicles in axon terminals preceding motor deficits, accumulation of Gallyas-positive aggregates, and cathepsin-positive vesicular clusters in axons in the sciatic nerve suggest that this denervation results from disturbances of axonal transport. This physiopathological mechanism might be responsible for motor signs observed in some human tauopathies, and for synaptic dysfunction resulting from alterations at the presynaptic level in these diseases.
Collapse
Affiliation(s)
- Emilie Audouard
- Laboratory of Histology, Neuroanatomy, and Neuropathology, Neuroscience Institute, Université Libre de Bruxelles, Brussels, Belgium
| | - Laura Van Hees
- Laboratory of Histology, Neuroanatomy, and Neuropathology, Neuroscience Institute, Université Libre de Bruxelles, Brussels, Belgium
| | - Valérie Suain
- Laboratory of Histology, Neuroanatomy, and Neuropathology, Neuroscience Institute, Université Libre de Bruxelles, Brussels, Belgium
| | - Zehra Yilmaz
- Laboratory of Histology, Neuroanatomy, and Neuropathology, Neuroscience Institute, Université Libre de Bruxelles, Brussels, Belgium
| | - Luc Poncelet
- Laboratory of Anatomy, Biomechanics and Organogenesis, Faculty of Medicine, Université Libre de Bruxelles, Brussels, Belgium
| | - Karelle Leroy
- Laboratory of Histology, Neuroanatomy, and Neuropathology, Neuroscience Institute, Université Libre de Bruxelles, Brussels, Belgium
| | - Jean-Pierre Brion
- Laboratory of Histology, Neuroanatomy, and Neuropathology, Neuroscience Institute, Université Libre de Bruxelles, Brussels, Belgium.
| |
Collapse
|
235
|
Mancuso R, Navarro X. Amyotrophic lateral sclerosis: Current perspectives from basic research to the clinic. Prog Neurobiol 2015; 133:1-26. [PMID: 26253783 DOI: 10.1016/j.pneurobio.2015.07.004] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 07/30/2015] [Accepted: 07/31/2015] [Indexed: 02/07/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive degeneration of upper and lower motoneurons, leading to muscle weakness and paralysis, and finally death. Considerable recent advances have been made in basic research and preclinical therapeutic attempts using experimental models, leading to increasing clinical and translational research in the context of this disease. In this review we aim to summarize the most relevant findings from a variety of aspects about ALS, including evaluation methods, animal models, pathophysiology, and clinical findings, with particular emphasis in understanding the role of every contributing mechanism to the disease for elucidating the causes underlying degeneration of motoneurons and the development of new therapeutic strategies.
Collapse
Affiliation(s)
- Renzo Mancuso
- Institute of Neurosciences and Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain
| | - Xavier Navarro
- Institute of Neurosciences and Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Bellaterra, Spain.
| |
Collapse
|
236
|
Alves CJ, Dariolli R, Jorge FM, Monteiro MR, Maximino JR, Martins RS, Strauss BE, Krieger JE, Callegaro D, Chadi G. Gene expression profiling for human iPS-derived motor neurons from sporadic ALS patients reveals a strong association between mitochondrial functions and neurodegeneration. Front Cell Neurosci 2015; 9:289. [PMID: 26300727 PMCID: PMC4523944 DOI: 10.3389/fncel.2015.00289] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 07/14/2015] [Indexed: 01/29/2023] Open
Abstract
Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease that leads to widespread motor neuron death, general palsy and respiratory failure. The most prevalent sporadic ALS form is not genetically inherited. Attempts to translate therapeutic strategies have failed because the described mechanisms of disease are based on animal models carrying specific gene mutations and thus do not address sporadic ALS. In order to achieve a better approach to study the human disease, human induced pluripotent stem cell (hiPSC)-differentiated motor neurons were obtained from motor nerve fibroblasts of sporadic ALS and non-ALS subjects using the STEMCCA Cre-Excisable Constitutive Polycistronic Lentivirus system and submitted to microarray analyses using a whole human genome platform. DAVID analyses of differentially expressed genes identified molecular function and biological process-related genes through Gene Ontology. REVIGO highlighted the related functions mRNA and DNA binding, GTP binding, transcription (co)-repressor activity, lipoprotein receptor binding, synapse organization, intracellular transport, mitotic cell cycle and cell death. KEGG showed pathways associated with Parkinson's disease and oxidative phosphorylation, highlighting iron homeostasis, neurotrophic functions, endosomal trafficking and ERK signaling. The analysis of most dysregulated genes and those representative of the majority of categorized genes indicates a strong association between mitochondrial function and cellular processes possibly related to motor neuron degeneration. In conclusion, iPSC-derived motor neurons from motor nerve fibroblasts of sporadic ALS patients may recapitulate key mechanisms of neurodegeneration and may offer an opportunity for translational investigation of sporadic ALS. Large gene profiling of differentiated motor neurons from sporadic ALS patients highlights mitochondrial participation in the establishment of autonomous mechanisms associated with sporadic ALS.
Collapse
Affiliation(s)
- Chrystian J Alves
- Department of Neurology, Neuroregeneration Center, University of São Paulo School of Medicine, University of São Paulo São Paulo, Brazil
| | - Rafael Dariolli
- Laboratory of Genetics and Molecular Cardiology/LIM13, Heart Institute, University of São Paulo School of Medicine São Paulo, Brazil
| | - Frederico M Jorge
- Department of Neurology, Neuroregeneration Center, University of São Paulo School of Medicine, University of São Paulo São Paulo, Brazil
| | - Matheus R Monteiro
- Department of Neurology, Neuroregeneration Center, University of São Paulo School of Medicine, University of São Paulo São Paulo, Brazil
| | - Jessica R Maximino
- Department of Neurology, Neuroregeneration Center, University of São Paulo School of Medicine, University of São Paulo São Paulo, Brazil
| | - Roberto S Martins
- Department of Neurosurgery, Surgical Center of Functional Neurosurgery, Clinics Hospital of University of São Paulo São Paulo, Brazil
| | - Bryan E Strauss
- Viral Vector Laboratory, Center for Translational Investigation in Oncology/LIM24, Cancer Institute of São Paulo, University of São Paulo School of Medicine São Paulo, Brazil
| | - José E Krieger
- Laboratory of Genetics and Molecular Cardiology/LIM13, Heart Institute, University of São Paulo School of Medicine São Paulo, Brazil
| | - Dagoberto Callegaro
- Department of Neurology, Neuroregeneration Center, University of São Paulo School of Medicine, University of São Paulo São Paulo, Brazil
| | - Gerson Chadi
- Department of Neurology, Neuroregeneration Center, University of São Paulo School of Medicine, University of São Paulo São Paulo, Brazil
| |
Collapse
|
237
|
Quantitative analysis of intraneuronal transport in human iPS neurons. J Pharmacol Sci 2015; 128:170-8. [DOI: 10.1016/j.jphs.2015.06.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 06/18/2015] [Accepted: 06/21/2015] [Indexed: 01/15/2023] Open
|
238
|
Nanosized TiO2 is internalized by dorsal root ganglion cells and causes damage via apoptosis. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2015; 11:1309-19. [DOI: 10.1016/j.nano.2015.04.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 03/29/2015] [Accepted: 04/03/2015] [Indexed: 12/21/2022]
|
239
|
Abstract
Glaucoma is increasingly recognized as a neurodegenerative disorder, characterized by the accelerated loss of retinal ganglion cells (RGCs) and their axons. Impaired axonal transport has been implicated as a pathogenic mechanism in a number of neurodegenerative diseases, including glaucoma. The long RGC axon, with its high metabolic demand and crucial role in conveying neurotrophic signals, relies heavily on intact axonal transport. In this mini review, we consider the evidence for transport disruption along RGCs in association with glaucoma and other intraocular pressure models. We give a brief overview of the axonal transport process and the methods by which it is assessed. Spatial and temporal patterns of axonal transport disruption are considered as well as the reversibility of these changes. Biomechanical, metabolic and cytoskeletal insults may underlie the development of axonal transport deficits, and there are multiple perspectives on the impact that transport disruption has on the RGC. Eliciting the role of impaired axonal transport in glaucoma pathogenesis may uncover novel therapeutic targets for protecting the optic nerve and preventing vision loss in glaucoma.
Collapse
Affiliation(s)
- Eamonn T Fahy
- a Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne , Melbourne , Victoria , Australia
| | - Vicki Chrysostomou
- a Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne , Melbourne , Victoria , Australia
| | - Jonathan G Crowston
- a Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, University of Melbourne , Melbourne , Victoria , Australia
| |
Collapse
|
240
|
Kadakkuzha BM, Spicer TP, Chase P, Richman JB, Hodder P, Puthanveettil SV. High-throughput screening for small molecule modulators of motor protein Kinesin. Assay Drug Dev Technol 2015; 12:470-80. [PMID: 25383721 DOI: 10.1089/adt.2014.579] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The kinesin superfamily of motor proteins are involved in the active transport of a large number of cargos such as organelles, proteins, and RNAs from the neuronal cell body to distal neuronal processes. Previously, we have shown that kinesin-mediated axonal transport of proteins and RNAs are important for long-term memory storage. Identification of small molecules that can activate or inhibit kinesins is of specific interest due to the significance of kinesin-mediated functions in neuronal health and plasticity. Here, we describe a high-throughput screening assay designed to specifically identify compounds that inhibit or activate adenosine triphosphatase activity of the kinesin 5B of humans. The luminescence-based assay that we developed is highly reproducible and robust. Using this approach, we screened a pharmacologically characterized compound collection and have identified small molecules with either activator or inhibitor-like activity. To further characterize screening hits, we also developed an orthogonal assay based on absorbance and a counter screen assay based on luminescence. Development of such assays is important to help identify small molecules that can be used in potential drug development efforts targeted at modulating the function of kinesin.
Collapse
Affiliation(s)
- Beena M Kadakkuzha
- 1 Department of Neuroscience, The Scripps Research Institute , Jupiter, Florida
| | | | | | | | | | | |
Collapse
|
241
|
Yang Y, Yu H, Shan X, Wang W, Liu X, Wang S, Tao N. Label-Free Tracking of Single Organelle Transportation in Cells with Nanometer Precision Using a Plasmonic Imaging Technique. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2015; 11:2878-84. [PMID: 25703098 PMCID: PMC4474744 DOI: 10.1002/smll.201403016] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Revised: 11/20/2014] [Indexed: 05/14/2023]
Abstract
Imaging and tracking of nano- and micrometer-sized organelles in cells with nanometer precision is crucial for understanding cellular behaviors at the molecular scale. Because of the fast intracellular dynamic processes, the imaging and tracking method must also be fast. In addition, to ensure that the observed dynamics is relevant to the native functions, it is critical to keep the cells under their native states. Here, a plasmonics-based imaging technique is demonstrated for studying the dynamics of organelles in 3D with high localization precision (5 nm) and temporal (10 ms) resolution. The technique is label-free and can track subcellular structures in the native state of the cells. Using the technique, nanometer steps of organelle (e.g., mitochondria) transportation are observed along neurite microtubules in primary neurons, and the 3D structure of neurite microtubule bundles is reconstructed at the nanometer scale from the tracks of the moving organelles.
Collapse
Affiliation(s)
- Yunze Yang
- Center for Biosensors and Bioelectronics, Biodesign Institute, Arizona State University, Tempe, Arizona 85287 USA
- School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287, USA
| | - Hui Yu
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Xiaonan Shan
- Center for Biosensors and Bioelectronics, Biodesign Institute, Arizona State University, Tempe, Arizona 85287 USA
| | - Wei Wang
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Xianwei Liu
- Center for Biosensors and Bioelectronics, Biodesign Institute, Arizona State University, Tempe, Arizona 85287 USA
| | - Shaopeng Wang
- Center for Biosensors and Bioelectronics, Biodesign Institute, Arizona State University, Tempe, Arizona 85287 USA
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Nongjian Tao
- Center for Biosensors and Bioelectronics, Biodesign Institute, Arizona State University, Tempe, Arizona 85287 USA
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
- School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287, USA
| |
Collapse
|
242
|
Rodriguez M, Rodriguez-Sabate C, Morales I, Sanchez A, Sabate M. Parkinson's disease as a result of aging. Aging Cell 2015; 14:293-308. [PMID: 25677794 PMCID: PMC4406659 DOI: 10.1111/acel.12312] [Citation(s) in RCA: 142] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/16/2014] [Indexed: 12/15/2022] Open
Abstract
It is generally considered that Parkinson's disease is induced by specific agents that degenerate a clearly defined population of dopaminergic neurons. Data commented in this review suggest that this assumption is not as clear as is often thought and that aging may be critical for Parkinson's disease. Neurons degenerating in Parkinson's disease also degenerate in normal aging, and the different agents involved in the etiology of this illness are also involved in aging. Senescence is a wider phenomenon affecting cells all over the body, whereas Parkinson's disease seems to be restricted to certain brain centers and cell populations. However, reviewed data suggest that Parkinson's disease may be a local expression of aging on cell populations which, by their characteristics (high number of synaptic terminals and mitochondria, unmyelinated axons, etc.), are highly vulnerable to the agents promoting aging. The development of new knowledge about Parkinson's disease could be accelerated if the research on aging and Parkinson's disease were planned together, and the perspective provided by gerontology gains relevance in this field.
Collapse
Affiliation(s)
- Manuel Rodriguez
- Laboratory of Neurobiology and Experimental Neurology, Department of Physiology, Faculty of Medicine, University of La LagunaLa Laguna, Spain
- Center for Networked Biomedical Research in Neurodegenerative Diseases (CIBERNED)La Laguna, Spain
| | - Clara Rodriguez-Sabate
- Center for Networked Biomedical Research in Neurodegenerative Diseases (CIBERNED)La Laguna, Spain
| | - Ingrid Morales
- Laboratory of Neurobiology and Experimental Neurology, Department of Physiology, Faculty of Medicine, University of La LagunaLa Laguna, Spain
- Center for Networked Biomedical Research in Neurodegenerative Diseases (CIBERNED)La Laguna, Spain
| | - Alberto Sanchez
- Laboratory of Neurobiology and Experimental Neurology, Department of Physiology, Faculty of Medicine, University of La LagunaLa Laguna, Spain
| | - Magdalena Sabate
- Rehabilitation Service, Department of Pharmacology and Physical Medicine, Faculty of Medicine, University of La LagunaLa Laguna, Spain
| |
Collapse
|
243
|
Stuppia G, Rizzo F, Riboldi G, Del Bo R, Nizzardo M, Simone C, Comi GP, Bresolin N, Corti S. MFN2-related neuropathies: Clinical features, molecular pathogenesis and therapeutic perspectives. J Neurol Sci 2015; 356:7-18. [PMID: 26143526 DOI: 10.1016/j.jns.2015.05.033] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 05/18/2015] [Accepted: 05/26/2015] [Indexed: 12/16/2022]
Abstract
Mitofusin 2 (MFN2) is a GTPase dynamin-like protein of the outer mitochondrial membrane, encoded in the nuclear genome by the MFN2 gene located on the short (p) arm of chromosome 1. MFN2 protein is involved in several intracellular pathways, but is mainly involved in a network that has an essential role in several mitochondrial functions, including fusion, axonal transport, interorganellar communication and mitophagy. Mutations in the gene encoding MFN2 are associated with Charcot-Marie-Tooth disease type 2A (CMT2A), a neurological disorder characterized by a wide clinical phenotype that involves the central and peripheral nervous system. Here, we present the clinical, genetic and neuropathological features of human diseases associated with MFN2 mutations. We also report proposed pathogenic mechanisms through which MFN2 mutations likely contribute to the development of neurodegeneration. MFN2-related disorders may occur more frequently than previously considered, and they may represent a paradigm for the study of the defective mitochondrial dynamics that seem to play a significant role in the molecular and cellular pathogenesis of common neurodegenerative diseases; thus they may also lead to the identification of related therapeutic targets.
Collapse
Affiliation(s)
- Giulia Stuppia
- Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy
| | - Federica Rizzo
- Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy
| | - Giulietta Riboldi
- Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy
| | - Roberto Del Bo
- Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy
| | - Monica Nizzardo
- Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy
| | - Chiara Simone
- Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy
| | - Giacomo P Comi
- Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy
| | - Nereo Bresolin
- Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy
| | - Stefania Corti
- Dino Ferrari Centre, Neuroscience Section, Department of Pathophysiology and Transplantation (DEPT), University of Milan, Neurology Unit, IRCCS Foundation Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122, Milan, Italy.
| |
Collapse
|
244
|
Lakadamyali M. Navigating the cell: how motors overcome roadblocks and traffic jams to efficiently transport cargo. Phys Chem Chem Phys 2015; 16:5907-16. [PMID: 24557020 DOI: 10.1039/c3cp55271c] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Intracellular transport plays an essential role in maintaining the organization of cells. The importance of long-range, bi-directional transport is evidenced by the fact that its failure goes hand in hand with several diseases including neurodegenerative diseases such as Alzheimer's and Amyotrophic Lateral Sclerosis. The nanoscale cellular transport machinery consisting of cytoskeletal tracks and motor-proteins is responsible for effectively delivering important materials to specific locations inside the cell. Motor-proteins manage to overcome several challenges in the crowded cellular environment to achieve well-coordinated and effective transport. In recent years, thanks to state-of-the-art single molecule biophysical tools, we have started to gain insights into the cellular traffic rules. This perspective summarizes the challenges that motors face in navigating the complex cytoskeleton and the lessons learned about transport in crowded environments from both bottom-up in vitro studies as well as top-down in vivo studies.
Collapse
Affiliation(s)
- Melike Lakadamyali
- ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, Av. Carl Friedrich Gauss, 3, 08860, Castelldefels, Barcelona, Spain.
| |
Collapse
|
245
|
Abstract
Electrophysiological examination can provide valuable information on functional abnormalities in patients with Parkinson's disease (PD). Although there are numerous reports on biochemical and molecular alterations in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced experimental parkinsonism in mice, the mode of electrophysiology in this animal model of PD is not clear. This study provides a comparative evaluation of corticomotor evoked potential (CMEP), compound muscle action potential (CMAP) and motor nerve conduction velocity (NCV) in mice treated with MPTP (30 mg/kg, ip, daily for 4 days) or saline (control group). Although the CMEP latencies were similar in both the groups, the CMEP amplitude was non-significantly decreased in MPTP-treated mice. There was a significant increase in the CMAP latency (1.37 ± 0.03 versus 1.20 ± 0.02 ms) and decrease in CMAP amplitude (4.50 ± 0.89 versus 8.31 ± 0.86 mV) in MPTP-treated mice as compared with control group. This prolonged conduction time resulted in a significant decrease in NCV in MPTP-treated mice (21.98 ± 0.54 m/s) as compared with control mice (24.47 ± 0.33 m/s). There was a significant depletion of striatal dopamine in MPTP-treated animals. These findings demonstrate that systemic administration of MPTP significantly impairs both the central and peripheral nervous systems in mice. However, the resemblance of this neurophysiological status with idiopathic PD or other animal models of PD is not clear and requires additional studies.
Collapse
Affiliation(s)
- Haseeb Ahmad Khan
- Analytical and Molecular Bioscience Research Group, Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| |
Collapse
|
246
|
Lamberts JT, Hildebrandt EN, Brundin P. Spreading of α-synuclein in the face of axonal transport deficits in Parkinson's disease: A speculative synthesis. Neurobiol Dis 2015; 77:276-83. [DOI: 10.1016/j.nbd.2014.07.002] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 07/02/2014] [Indexed: 11/30/2022] Open
|
247
|
Bressloff PC, Levien E. Synaptic democracy and vesicular transport in axons. PHYSICAL REVIEW LETTERS 2015; 114:168101. [PMID: 25955074 DOI: 10.1103/physrevlett.114.168101] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Indexed: 06/04/2023]
Abstract
Synaptic democracy concerns the general problem of how regions of an axon or dendrite far from the cell body (soma) of a neuron can play an effective role in neuronal function. For example, stimulated synapses far from the soma are unlikely to influence the firing of a neuron unless some sort of active dendritic processing occurs. Analogously, the motor-driven transport of newly synthesized proteins from the soma to presynaptic targets along the axon tends to favor the delivery of resources to proximal synapses. Both of these phenomena reflect fundamental limitations of transport processes based on a localized source. In this Letter, we show that a more democratic distribution of proteins along an axon can be achieved by making the transport process less efficient. This involves two components: bidirectional or "stop-and-go" motor transport (which can be modeled in terms of advection-diffusion), and reversible interactions between motor-cargo complexes and synaptic targets. Both of these features have recently been observed experimentally. Our model suggests that, just as in human societies, there needs to be a balance between "efficiency" and "equality".
Collapse
Affiliation(s)
- Paul C Bressloff
- Department of Mathematics, University of Utah, 155 South 1400 East, Salt Lake City, Utah 84112, USA
| | - Ethan Levien
- Department of Mathematics, University of Utah, 155 South 1400 East, Salt Lake City, Utah 84112, USA
| |
Collapse
|
248
|
Identification of 12/15-lipoxygenase as a regulator of axon degeneration through high-content screening. J Neurosci 2015; 35:2927-41. [PMID: 25698732 DOI: 10.1523/jneurosci.2936-14.2015] [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] [Indexed: 11/21/2022] Open
Abstract
Axon degeneration is a programed process that takes place during development, in response to neuronal injury, and as a component of neurodegenerative disease pathology, yet the molecular mechanisms that drive this process remain poorly defined. In this study, we have developed a semi-automated, 384-well format axon degeneration assay in rat dorsal root ganglion (DRG) neurons using a trophic factor withdrawal paradigm. Using this setup, we have screened a library of known drugs and bioactives to identify several previously unappreciated regulators of axon degeneration, including lipoxygenases. Multiple structurally distinct lipoxygenase inhibitors as well as mouse DRG neurons lacking expression of 12/15-lipoxygenase display protection of axons in this context. Retinal ganglion cell axons from 12/15-lipoxygenase-null mice were similarly protected from degeneration following nerve crush injury. Through additional mechanistic studies, we demonstrate that lipoxygenases act cell autonomously within neurons to regulate degeneration, and are required for mitochondrial permeabilization and caspase activation in the axon. These findings suggest that these enzymes may represent an attractive target for treatment of neuropathies and provide a potential mechanism for the neuroprotection observed in various settings following lipoxygenase inhibitor treatment.
Collapse
|
249
|
Bartus RT, Kordower JH, Johnson EM, Brown L, Kruegel BR, Chu Y, Baumann TL, Lang AE, Olanow CW, Herzog CD. Post-mortem assessment of the short and long-term effects of the trophic factor neurturin in patients with α-synucleinopathies. Neurobiol Dis 2015; 78:162-71. [PMID: 25841760 DOI: 10.1016/j.nbd.2015.03.023] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Revised: 03/13/2015] [Accepted: 03/23/2015] [Indexed: 11/29/2022] Open
Abstract
Substantial interest persists for developing neurotrophic factors to treat neurodegenerative diseases. At the same time, significant progress has been made in implementing gene therapy as a means to provide long-term expression of bioactive neurotrophic factors to targeted sites in the brain. Nonetheless, to date, no double-blind clinical trial has achieved positive results on its primary endpoint despite robust benefits achieved in animal models. A major issue with advancing the field is the paucity of information regarding the expression and effects of neurotrophic factors in human neurodegenerative brain, relative to the well-characterized responses in animal models. To help fill this information void, we examined post-mortem brain tissue from four patients with nigrostriatal degeneration who had participated in clinical trials testing gene delivery of neurturin to the putamen of patients. Each had died of unrelated causes ranging from 1.5-to-3-months (2 Parkinson's disease patients), to 4+-years (1 Parkinson's disease and 1 multiple-system atrophy-parkinsonian type patient) following gene therapy. Quantitative and immunohistochemical evaluation of neurturin, alpha-synuclein, tyrosine hydroxylase (TH) and an oligodendroglia marker (Olig 2) were performed in each brain. Comparable volumes-of-expression of neurturin were seen in the putamen in all cases (~15-22%; mean=18.5%). TH-signal in the putamen was extremely sparse in the shorter-term cases. A 6-fold increase was seen in longer-term cases, but was far less than achieved in animal models of nigrostriatal degeneration with similar or even far less NRTN exposure. Less than 1% of substantia nigra (SN) neurons stained for neurturin in the shorter-term cases. A 15-fold increase was seen in the longer-term cases, but neurturin was still only detected in ~5% of nigral cells. These data provide unique insight into the functional status of advanced, chronic nigrostriatal degeneration in human brain and the response of these neurons to neurotrophic factor stimulation. They demonstrate mild but persistent expression of gene-mediated neurturin over 4-years, with an apparent, time-related amplification of its transport and biological effects, albeit quite weak, and provide unique information to help plan and design future trials.
Collapse
Affiliation(s)
- R T Bartus
- RTBioconsultants, Inc., San Diego, CA, USA; Ceregene, Inc, USA.
| | - J H Kordower
- Rush Presbyterian Medical Center, Chicago, IL, USA
| | - E M Johnson
- Washington University Medical School, St. Louis, MO, USA
| | | | | | - Y Chu
- Rush Presbyterian Medical Center, Chicago, IL, USA
| | - T L Baumann
- Isis Pharmaceuticals, Carlsbad, CA, USA; Ceregene, Inc, USA
| | - A E Lang
- Toronto Western Hospital, Toronto, Canada
| | - C W Olanow
- Mount Sinai School of Medicine, NYC, USA
| | | |
Collapse
|
250
|
Bernard-Marissal N, Médard JJ, Azzedine H, Chrast R. Dysfunction in endoplasmic reticulum-mitochondria crosstalk underlies SIGMAR1 loss of function mediated motor neuron degeneration. Brain 2015; 138:875-90. [PMID: 25678561 DOI: 10.1093/brain/awv008] [Citation(s) in RCA: 166] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023] Open
Abstract
Mutations in Sigma 1 receptor (SIGMAR1) have been previously identified in patients with amyotrophic lateral sclerosis and disruption of Sigmar1 in mouse leads to locomotor deficits. However, cellular mechanisms underlying motor phenotypes in human and mouse with disturbed SIGMAR1 function have not been described so far. Here we used a combination of in vivo and in vitro approaches to investigate the role of SIGMAR1 in motor neuron biology. Characterization of Sigmar1(-/-) mice revealed that affected animals display locomotor deficits associated with muscle weakness, axonal degeneration and motor neuron loss. Using primary motor neuron cultures, we observed that pharmacological or genetic inactivation of SIGMAR1 led to motor neuron axonal degeneration followed by cell death. Disruption of SIGMAR1 function in motor neurons disturbed endoplasmic reticulum-mitochondria contacts, affected intracellular calcium signalling and was accompanied by activation of endoplasmic reticulum stress and defects in mitochondrial dynamics and transport. These defects were not observed in cultured sensory neurons, highlighting the exacerbated sensitivity of motor neurons to SIGMAR1 function. Interestingly, the inhibition of mitochondrial fission was sufficient to induce mitochondria axonal transport defects as well as axonal degeneration similar to the changes observed after SIGMAR1 inactivation or loss. Intracellular calcium scavenging and endoplasmic reticulum stress inhibition were able to restore mitochondrial function and consequently prevent motor neuron degeneration. These results uncover the cellular mechanisms underlying motor neuron degeneration mediated by loss of SIGMAR1 function and provide therapeutically relevant insight into motor neuronal diseases.
Collapse
Affiliation(s)
- Nathalie Bernard-Marissal
- 1 Department of Medical Genetics, University of Lausanne, CH-1005 Lausanne, Switzerland 2 Neurodegenerative Studies Laboratory, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Jean-Jacques Médard
- 1 Department of Medical Genetics, University of Lausanne, CH-1005 Lausanne, Switzerland
| | - Hamid Azzedine
- 1 Department of Medical Genetics, University of Lausanne, CH-1005 Lausanne, Switzerland 3 Institute of Neuropathology, RWTH Aachen University, 52074 Aachen, Germany
| | - Roman Chrast
- 1 Department of Medical Genetics, University of Lausanne, CH-1005 Lausanne, Switzerland 4 Department of Neuroscience and Department of Clinical Neuroscience, Karolinska Institutet, 171 77 Stockholm, Sweden
| |
Collapse
|