1
|
Cheung SW, Bhavnani E, Simmons DG, Bellingham MC, Noakes PG. Perineuronal nets are phagocytosed by MMP-9 expressing microglia and astrocytes in the SOD1 G93A ALS mouse model. Neuropathol Appl Neurobiol 2024; 50:e12982. [PMID: 38742276 DOI: 10.1111/nan.12982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 04/22/2024] [Accepted: 04/25/2024] [Indexed: 05/16/2024]
Abstract
AIMS Perineuronal nets (PNNs) are an extracellular matrix structure that encases excitable neurons. PNNs play a role in neuroprotection against oxidative stress. Oxidative stress within motor neurons can trigger neuronal death, which has been implicated in amyotrophic lateral sclerosis (ALS). We investigated the spatio-temporal timeline of PNN breakdown and the contributing cellular factors in the SOD1G93A strain, a fast-onset ALS mouse model. METHODS This was conducted at the presymptomatic (P30), onset (P70), mid-stage (P130), and end-stage disease (P150) using immunofluorescent microscopy, as this characterisation has not been conducted in the SOD1G93A strain. RESULTS We observed a significant breakdown of PNNs around α-motor neurons in the ventral horn of onset and mid-stage disease SOD1G93A mice compared with wild-type controls. This was observed with increased numbers of microglia expressing matrix metallopeptidase-9 (MMP-9), an endopeptidase that degrades PNNs. Microglia also engulfed PNN components in the SOD1G93A mouse. Further increases in microglia and astrocyte number, MMP-9 expression, and engulfment of PNN components by glia were observed in mid-stage SOD1G93A mice. This was observed with increased expression of fractalkine, a signal for microglia engulfment, within α-motor neurons of SOD1G93A mice. Following PNN breakdown, α-motor neurons of onset and mid-stage SOD1G93A mice showed increased expression of 3-nitrotyrosine, a marker for protein oxidation, which could render them vulnerable to death. CONCLUSIONS Our observations suggest that increased numbers of MMP-9 expressing glia and their subsequent engulfment of PNNs around α-motor neurons render these neurons sensitive to oxidative damage and eventual death in the SOD1G93A ALS model mouse.
Collapse
Affiliation(s)
- Sang Won Cheung
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Australia
| | - Ekta Bhavnani
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Australia
| | - David G Simmons
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Australia
| | - Mark C Bellingham
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Australia
| | - Peter G Noakes
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Australia
- Queensland Brain Institute, The University of Queensland, St. Lucia, Australia
| |
Collapse
|
2
|
Al-Mhanawi B, Marti MB, Morrison SD, Gupta P, Alani M, Noakes PG, Wolvetang EJ, Shaker MR. Protocol for generating embedding-free brain organoids enriched with oligodendrocytes. STAR Protoc 2023; 4:102725. [PMID: 37976154 PMCID: PMC10692957 DOI: 10.1016/j.xpro.2023.102725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/08/2023] [Accepted: 10/31/2023] [Indexed: 11/19/2023] Open
Abstract
In response to the scarcity of advanced in vitro models dedicated to human CNS white matter research, we present a protocol to generate neuroectoderm-derived embedding-free human brain organoids enriched with oligodendrocytes. We describe steps for neuroectoderm differentiation, development of neural spheroids, and their transferal to Matrigel. We then detail procedures for the development, maturation, and application of oligodendrocyte-enriched brain organoids. The presence of myelin-producing cells makes these organoids useful for studying human white matter diseases, such as leukodystrophy.
Collapse
Affiliation(s)
- Bahaa Al-Mhanawi
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Marta Boira Marti
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Sean D Morrison
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Pallavi Gupta
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, QLD 4072, Australia; University of Queensland - IIT Delhi Academy of Research (UQIDAR), Hauz Khas, New Delhi 110016, India; Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Maath Alani
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Peter G Noakes
- Queensland Brain Institute, The University of Queensland, St. Lucia, QLD 4072, Australia; School of Biomedical Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Ernst J Wolvetang
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, QLD 4072, Australia.
| | - Mohammed R Shaker
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St. Lucia, QLD 4072, Australia.
| |
Collapse
|
3
|
Shi D, Wong JKY, Zhu K, Noakes PG, Rammes G. The Anaesthetics Isoflurane and Xenon Reverse the Synaptotoxic Effects of Aβ 1-42 on Megf10-Dependent Astrocytic Synapse Elimination and Spine Density in Ex Vivo Hippocampal Brain Slices. Int J Mol Sci 2023; 24:ijms24020912. [PMID: 36674434 PMCID: PMC9861496 DOI: 10.3390/ijms24020912] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 12/28/2022] [Accepted: 12/28/2022] [Indexed: 01/06/2023] Open
Abstract
It has been hypothesised that inhalational anaesthetics such as isoflurane (Iso) may trigger the pathogenesis of Alzheimer's disease (AD), while the gaseous anaesthetic xenon (Xe) exhibits many features of a putative neuroprotective agent. Loss of synapses is regarded as one key cause of dementia in AD. Multiple EGF-like domains 10 (MEGF10) is one of the phagocytic receptors which assists the elimination of synapses by astrocytes. Here, we investigated how β-amyloid peptide 1-42 (Aβ1-42), Iso and Xe interact with MEGF10-dependent synapse elimination. Murine cultured astrocytes as well as cortical and hippocampal ex vivo brain slices were treated with either Aβ1-42, Iso or Xe and the combination of Aβ1-42 with either Iso or Xe. We quantified MEGF10 expression in astrocytes and dendritic spine density (DSD) in slices. In brain slices of wild type and AAV-induced MEGF10 knock-down mice, antibodies against astrocytes (GFAP), pre- (synaptophysin) and postsynaptic (PSD95) components were used for co-localization analyses by means of immunofluorescence-imaging and 3D rendering techniques. Aβ1-42 elevated pre- and postsynaptic components inside astrocytes and decreased DSD. The combined application with either Iso or Xe reversed these effects. In the presence of Aβ1-42 both anaesthetics decreased MEGF10 expression. AAV-induced knock-down of MEGF10 reduced the pre- and postsynaptic marker inside astrocytes. The presented data suggest Iso and Xe are able to reverse the Aβ1-42-induced enhancement of synaptic elimination in ex vivo hippocampal brain slices, presumably through MEGF10 downregulation.
Collapse
Affiliation(s)
- Dai Shi
- Department of Anesthesiology and Intensive Care, Klinikum Rechts der Isar, Ismaningerstraße 22, 81675 Munich, Germany
| | - Jaime K. Y. Wong
- School of Biomedical Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Kaichuan Zhu
- German Center for Neurodegenerative Diseases, Feodor-Lynen-Straße 23, 81377 Munich, Germany
- Center for Neuropathology and Prion Research, Feodor-Lynen-Straße 23, 81377 Munich, Germany
| | - Peter G. Noakes
- School of Biomedical Sciences, The University of Queensland, St. Lucia, QLD 4072, Australia
- Queensland Brain Institute, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Gerhard Rammes
- Department of Anesthesiology and Intensive Care, Klinikum Rechts der Isar, Ismaningerstraße 22, 81675 Munich, Germany
- Correspondence:
| |
Collapse
|
4
|
Ding Q, Kesavan K, Lee KM, Wimberger E, Robertson T, Gill M, Power D, Chang J, Fard AT, Mar JC, Henderson RD, Heggie S, McCombe PA, Jeffree RL, Colditz MJ, Hilliard MA, Ng DCH, Steyn FJ, Phillips WD, Wolvetang EJ, Ngo ST, Noakes PG. Impaired signaling for neuromuscular synaptic maintenance is a feature of Motor Neuron Disease. Acta Neuropathol Commun 2022; 10:61. [PMID: 35468848 PMCID: PMC9040261 DOI: 10.1186/s40478-022-01360-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 04/06/2022] [Indexed: 11/17/2022] Open
Abstract
A central event in the pathogenesis of motor neuron disease (MND) is the loss of neuromuscular junctions (NMJs), yet the mechanisms that lead to this event in MND remain to be fully elucidated. Maintenance of the NMJ relies upon neural agrin (n-agrin) which, when released from the nerve terminal, activates the postsynaptic Muscle Specific Kinase (MuSK) signaling complex to stabilize clusters of acetylcholine receptors. Here, we report that muscle from MND patients has an increased proportion of slow fibers and muscle fibers with smaller diameter. Muscle cells cultured from MND biopsies failed to form large clusters of acetylcholine receptors in response to either non-MND human motor axons or n-agrin. Furthermore, levels of expression of MuSK, and MuSK-complex components: LRP4, Caveolin-3, and Dok7 differed between muscle cells cultured from MND patients compared to those from non-MND controls. To our knowledge, this is the first time a fault in the n-agrin-LRP4-MuSK signaling pathway has been identified in muscle from MND patients. Our results highlight the n-agrin-LRP4-MuSK signaling pathway as a potential therapeutic target to prolong muscle function in MND.
Collapse
|
5
|
Ding Q, Chaplin J, Morris MJ, Hilliard MA, Wolvetang E, Ng DCH, Noakes PG. TDP-43 Mutation Affects Stress Granule Dynamics in Differentiated NSC-34 Motoneuron-Like Cells. Front Cell Dev Biol 2021; 9:611601. [PMID: 34169068 PMCID: PMC8217991 DOI: 10.3389/fcell.2021.611601] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 05/10/2021] [Indexed: 12/13/2022] Open
Abstract
Amyotrophic Lateral Sclerosis (ALS) is characterized by degeneration of motor neurons in the brain and spinal cord. Cytoplasmic inclusions of TDP-43 are frequently reported in motor neurons of ALS patients. TDP-43 has also been shown to associate with stress granules (SGs), a complex of proteins and mRNAs formed in response to stress stimuli that temporarily sequester mRNA translation. The effect of pathogenic TDP-43 mutations within glycine-rich regions (where the majority of ALS-causing TDP-43 mutations occur) on SG dynamics in motor neurons is poorly understood. To address this issue, we generated murine NSC-34 cell lines that stably over-express wild type TDP-43 (TDP-43WT) or mutant forms (ALS-causing TDP-43 mutations TDP-43A315T or TDP-43M337V). We then differentiated these NSC-34 lines into motoneuron-like cells and evaluated SG formation and disassembly kinetics in response to oxidative or osmotic stress treatment. Wild type and mutant TDP-43 appeared to be largely retained in the nucleus following exposure to arsenite-induced oxidative stress. Upon arsenite removal, mutant TDP-43 clearly accumulated within HuR positive SGs in the cytoplasm, whereas TDP-43WT remained mostly within the nucleus. 24 h following arsenite removal, all SGs were disassembled in both wild type and mutant TDP-43 expressing cells. By contrast, we observed significant differences in the dynamics of mutant TDP-43 association with SGs in response to hyperosmotic stress. Specifically, in response to sorbitol treatment, TDP-43WT remained in the nucleus, whereas mutant TDP-43 relocalized to HuR positive SGs in the cytoplasm following exposure to sorbitol stress, resulting in a significant increase in TDP-43 SG numbers. These SGs remained assembled for 24 h following removal of sorbitol. Our data reveal that under certain stress conditions the rates of SG formation and disassembly is modulated by TDP-43 mutations associated with ALS, and suggest that this may be an early event in the seeding of insoluble cytoplasmic inclusions observed in ALS.
Collapse
Affiliation(s)
- Qiao Ding
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Justin Chaplin
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia.,Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Matthew J Morris
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Massimo A Hilliard
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia.,Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Ernst Wolvetang
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia
| | - Dominic C H Ng
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Peter G Noakes
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia.,Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| |
Collapse
|
6
|
Fogarty MJ, Mu EWH, Lavidis NA, Noakes PG, Bellingham MC. Size‐dependent dendritic maladaptations of hypoglossal motor neurons in SOD1
G93A
mice. Anat Rec (Hoboken) 2020; 304:1562-1581. [DOI: 10.1002/ar.24542] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 09/14/2020] [Accepted: 09/22/2020] [Indexed: 12/14/2022]
Affiliation(s)
- Matthew J. Fogarty
- School of Biomedical Sciences The University of Queensland St Lucia Australia
- Department of Physiology and Biomedical Engineering, Mayo Clinic Rochester Minnesota USA
| | - Erica W. H. Mu
- School of Biomedical Sciences The University of Queensland St Lucia Australia
| | - Nickolas A. Lavidis
- School of Biomedical Sciences The University of Queensland St Lucia Australia
| | - Peter G. Noakes
- School of Biomedical Sciences The University of Queensland St Lucia Australia
- Queensland Brain Institute The University of Queensland St Lucia Australia
| | - Mark C. Bellingham
- School of Biomedical Sciences The University of Queensland St Lucia Australia
| |
Collapse
|
7
|
Odierna GL, Kerwin SK, Harris LE, Shin GJE, Lavidis NA, Noakes PG, Millard SS. Dscam2 suppresses synaptic strength through a PI3K-dependent endosomal pathway. J Cell Biol 2020; 219:151621. [PMID: 32259198 PMCID: PMC7265308 DOI: 10.1083/jcb.201909143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 02/19/2020] [Accepted: 03/05/2020] [Indexed: 11/22/2022] Open
Abstract
Dscam2 is a cell surface protein required for neuronal development in Drosophila; it can promote neural wiring through homophilic recognition that leads to either adhesion or repulsion between neurites. Here, we report that Dscam2 also plays a post-developmental role in suppressing synaptic strength. This function is dependent on one of two distinct extracellular isoforms of the protein and is autonomous to motor neurons. We link the PI3K enhancer, Centaurin gamma 1A, to the Dscam2-dependent regulation of synaptic strength and show that changes in phosphoinositide levels correlate with changes in endosomal compartments that have previously been associated with synaptic strength. Using transmission electron microscopy, we find an increase in synaptic vesicles at Dscam2 mutant active zones, providing a rationale for the increase in synaptic strength. Our study provides the first evidence that Dscam2 can regulate synaptic physiology and highlights how diverse roles of alternative protein isoforms can contribute to unique aspects of brain development and function.
Collapse
Affiliation(s)
- G Lorenzo Odierna
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Sarah K Kerwin
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Lucy E Harris
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Grace Ji-Eun Shin
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia.,Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY
| | - Nickolas A Lavidis
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Peter G Noakes
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia.,Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - S Sean Millard
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| |
Collapse
|
8
|
Ferreira N, Andoniou CE, Perks KL, Ermer JA, Rudler DL, Rossetti G, Periyakaruppiah A, Wong JKY, Rackham O, Noakes PG, Degli-Esposti MA, Filipovska A. Murine cytomegalovirus infection exacerbates complex IV deficiency in a model of mitochondrial disease. PLoS Genet 2020; 16:e1008604. [PMID: 32130224 PMCID: PMC7055822 DOI: 10.1371/journal.pgen.1008604] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 01/10/2020] [Indexed: 11/30/2022] Open
Abstract
The influence of environmental insults on the onset and progression of mitochondrial diseases is unknown. To evaluate the effects of infection on mitochondrial disease we used a mouse model of Leigh Syndrome, where a missense mutation in the Taco1 gene results in the loss of the translation activator of cytochrome c oxidase subunit I (TACO1) protein. The mutation leads to an isolated complex IV deficiency that mimics the disease pathology observed in human patients with TACO1 mutations. We infected Taco1 mutant and wild-type mice with a murine cytomegalovirus and show that a common viral infection exacerbates the complex IV deficiency in a tissue-specific manner. We identified changes in neuromuscular morphology and tissue-specific regulation of the mammalian target of rapamycin pathway in response to viral infection. Taken together, we report for the first time that a common stress condition, such as viral infection, can exacerbate mitochondrial dysfunction in a genetic model of mitochondrial disease. Mitochondrial diseases are the most commonly inherited metabolic disorders that are heterogenic and have varied disease onset and progression. Acquired infections and the associated inflammatory responses are known triggers for mitochondrial disease in the clinic and can cause progressive deterioration in patients with mitochondrial disease. Knowledge of how an infection causes and contributes to the progression of mitochondrial disease is completely lacking and has never before been investigated. Here we examined the effects of a viral infection in a model of energy dysfunction and identified that cytomegalovirus can worsen the progression of mitochondrial disease symptoms.
Collapse
Affiliation(s)
- Nicola Ferreira
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia
- Centre for Medical Research, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Christopher E. Andoniou
- Infection and Immunity Program and Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Centre for Experimental Immunology, Lions Eye Institute, Perth, Western Australia, Australia
| | - Kara L. Perks
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia
- Centre for Medical Research, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Judith A. Ermer
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia
- Centre for Medical Research, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Danielle L. Rudler
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia
- Centre for Medical Research, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Giulia Rossetti
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia
- Centre for Medical Research, The University of Western Australia, Nedlands, Western Australia, Australia
| | - Ambika Periyakaruppiah
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland, Australia
| | - Jamie K. Y. Wong
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland, Australia
| | - Oliver Rackham
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia
- School of Pharmacy and Biomedical Sciences, Curtin University, Bentley, Western Australia, Australia
- Curtin Health Innovation Research Institute, Curtin University, Bentley, Western Australia, Australia
- Telethon Kids Institute, QEII Medical Centre, Nedlands, Western Australia, Australia
| | - Peter G. Noakes
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland, Australia
- Queensland Brain Institute, The University of Queensland, St. Lucia, Queensland, Australia
| | - Mariapia A. Degli-Esposti
- Infection and Immunity Program and Department of Microbiology, Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Centre for Experimental Immunology, Lions Eye Institute, Perth, Western Australia, Australia
| | - Aleksandra Filipovska
- Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, Western Australia, Australia
- Centre for Medical Research, The University of Western Australia, Nedlands, Western Australia, Australia
- Telethon Kids Institute, QEII Medical Centre, Nedlands, Western Australia, Australia
- School of Molecular Sciences, The University of Western Australia, Crawley, Western Australia, Australia
- * E-mail:
| |
Collapse
|
9
|
Kumar V, Lee JD, Clark RJ, Noakes PG, Taylor SM, Woodruff TM. Preclinical Pharmacokinetics of Complement C5a Receptor Antagonists PMX53 and PMX205 in Mice. ACS Omega 2020; 5:2345-2354. [PMID: 32064396 PMCID: PMC7017397 DOI: 10.1021/acsomega.9b03735] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 01/21/2020] [Indexed: 05/16/2023]
Abstract
The cyclic hexapeptides PMX53 and PMX205 are potent noncompetitive inhibitors of complement C5a receptor 1 (C5aR1). They are widely utilized to study the role of C5aR1 in mouse models, including central nervous system (CNS) disease, and are dosed through a variety of routes of administration. However, a comprehensive pharmacokinetics analysis of these drugs has not been reported. In this study, the blood and CNS pharmacokinetics of PMX53 and PMX205 were performed in mice following intravenous, intraperitoneal, subcutaneous, and oral administration at identical doses. The absorption and distribution of both drugs were rapid and followed a two-compartment model with elimination half-lives of ∼20 min for both compounds. Urinary excretion was the major route of elimination following intravenous dosing with ∼50% of the drug excreted unchanged within the first 12 h. Oral bioavailability of PMX205 was higher than that of PMX53 (23% versus 9%), and PMX205 was also more efficient than PMX53 at entering the intact CNS. In comparison to other routes, subcutaneous administration of PMX205 resulted in high bioavailability (above 90%), as well as prolonged plasma and CNS exposure. Finally, repeated daily oral or subcutaneous administration of PMX205 demonstrated no accumulation of drug in blood, the brain, or the spinal cord, promoting its safety for chronic dosing. These results will be helpful in correlating the desired therapeutic effects of these C5aR1 antagonists with their pharmacokinetic profile. It also suggests that subcutaneous dosing of PMX205 may be an appropriate route of administration for future clinical testing in neurological disease.
Collapse
Affiliation(s)
- Vinod Kumar
- School
of Biomedical Sciences, The University of
Queensland, St Lucia, Brisbane, QLD 4072, Australia
| | - John D. Lee
- School
of Biomedical Sciences, The University of
Queensland, St Lucia, Brisbane, QLD 4072, Australia
- University
of Queensland Centre for Clinical Research, the University of Queensland, Brisbane, QLD 4029, Australia
| | - Richard J. Clark
- School
of Biomedical Sciences, The University of
Queensland, St Lucia, Brisbane, QLD 4072, Australia
| | - Peter G. Noakes
- School
of Biomedical Sciences, The University of
Queensland, St Lucia, Brisbane, QLD 4072, Australia
- Queensland
Brain Institute, the University of Queensland,
St Lucia, Brisbane, QLD 4072, Australia
| | - Stephen M. Taylor
- School
of Biomedical Sciences, The University of
Queensland, St Lucia, Brisbane, QLD 4072, Australia
| | - Trent M. Woodruff
- School
of Biomedical Sciences, The University of
Queensland, St Lucia, Brisbane, QLD 4072, Australia
- Wesley
Medical Research, The Wesley Hospital, Auchenflower, Brisbane, QLD 4066, Australia
- . Phone: +61-7-336 52924. Fax: +61-7-336-51766
| |
Collapse
|
10
|
Ge D, Noakes PG, Lavidis NA. What are Neurotransmitter Release Sites and Do They Interact? Neuroscience 2020; 425:157-168. [DOI: 10.1016/j.neuroscience.2019.11.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2019] [Revised: 11/10/2019] [Accepted: 11/11/2019] [Indexed: 12/22/2022]
|
11
|
Fogarty MJ, Mu EWH, Lavidis NA, Noakes PG, Bellingham MC. Size-Dependent Vulnerability of Lumbar Motor Neuron Dendritic Degeneration in SOD1 G93A Mice. Anat Rec (Hoboken) 2019; 303:1455-1471. [PMID: 31509351 DOI: 10.1002/ar.24255] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2019] [Revised: 05/22/2019] [Accepted: 06/29/2019] [Indexed: 12/14/2022]
Abstract
The motor neuron (MN) soma surface area is correlated with motor unit type. Larger MNs innervate fast fatigue-intermediate (FInt) or fast-fatiguable (FF) muscle fibers in type FInt and FF motor units, respectively. Smaller MNs innervate slow-twitch fatigue-resistant (S) or fast fatigue-resistant (FR) muscle fibers in type S and FR motor units, respectively. In amyotrophic lateral sclerosis (ALS), FInt and FF motor units are more vulnerable, with denervation and MN death occurring for these units before the more resilient S and FR units. Abnormal MN dendritic arbors have been observed in ALS in humans and rodent models. We used a Golgi-Cox impregnation protocol to examine soma size-dependent changes in the dendritic morphology of lumbar MNs in SOD1G93A mice, a model of ALS, at pre-symptomatic, onset and mid-disease stages. In wildtype control mice, the relationship between MN soma surface area and dendritic length or dendritic spine number was highly linear (i.e., increased MN soma size correlated with increased dendritic length and spines). By contrast, in SOD1G93A mice, this linear relationship was lost and dendritic length reduction and spine loss were observed in larger MNs, from pre-symptomatic stages onward. These changes correlated with the neuromotor symptoms of ALS in rodent models. At presymptomatic ages, changes were restricted to the larger MNs, likely to comprise vulnerable FInt and FF motor units. Our results suggest morphological changes of MN dendrites and dendritic spines are likely to contribute ALS pathogenesis, not compensate for it. Anat Rec, 303:1455-1471, 2020. © 2019 American Association for Anatomy.
Collapse
Affiliation(s)
- Matthew J Fogarty
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland, Australia.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota
| | - Erica W H Mu
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Nickolas A Lavidis
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland, Australia
| | - Peter G Noakes
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland, Australia.,Queensland Brain Institute, The University of Queensland, St Lucia, Queensland, Australia
| | - Mark C Bellingham
- School of Biomedical Sciences, The University of Queensland, St Lucia, Queensland, Australia
| |
Collapse
|
12
|
Pradhan J, Noakes PG, Bellingham MC. The Role of Altered BDNF/TrkB Signaling in Amyotrophic Lateral Sclerosis. Front Cell Neurosci 2019; 13:368. [PMID: 31456666 PMCID: PMC6700252 DOI: 10.3389/fncel.2019.00368] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 07/29/2019] [Indexed: 12/11/2022] Open
Abstract
Brain derived neurotrophic factor (BDNF) is well recognized for its neuroprotective functions, via activation of its high affinity receptor, tropomysin related kinase B (TrkB). In addition, BDNF/TrkB neuroprotective functions can also be elicited indirectly via activation of adenosine 2A receptors (A2aRs), which in turn transactivates TrkB. Evidence suggests that alterations in BDNF/TrkB, including TrkB transactivation by A2aRs, can occur in several neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). Although enhancing BDNF has been a major goal for protection of dying motor neurons (MNs), this has not been successful. Indeed, there is emerging in vitro and in vivo evidence suggesting that an upregulation of BDNF/TrkB can cause detrimental effects on MNs, making them more vulnerable to pathophysiological insults. For example, in ALS, early synaptic hyper-excitability of MNs is thought to enhance BDNF-mediated signaling, thereby causing glutamate excitotoxicity, and ultimately MN death. Moreover, direct inhibition of TrkB and A2aRs has been shown to protect MNs from these pathophysiological insults, suggesting that modulation of BDNF/TrkB and/or A2aRs receptors may be important in early disease pathogenesis in ALS. This review highlights the relevance of pathophysiological actions of BDNF/TrkB under certain circumstances, so that manipulation of BDNF/TrkB and A2aRs may give rise to alternate neuroprotective therapeutic strategies in the treatment of neural diseases such as ALS.
Collapse
Affiliation(s)
- Jonu Pradhan
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Peter G Noakes
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia.,Queensland Brain Institute, The University of Queensland, Brisbane, QLD, Australia
| | - Mark C Bellingham
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia
| |
Collapse
|
13
|
Parker SE, Hanton AM, Stefanou SN, Noakes PG, Woodruff TM, Lee JD. Revisiting the role of the innate immune complement system in ALS. Neurobiol Dis 2019; 127:223-232. [DOI: 10.1016/j.nbd.2019.03.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 02/21/2019] [Accepted: 03/04/2019] [Indexed: 12/11/2022] Open
|
14
|
Ge D, Noakes PG, Lavidis NA. Seasonal comparison of the neuromuscular junction morphology of Bufo marinus. J Comp Neurol 2019; 527:1931-1939. [PMID: 30737989 DOI: 10.1002/cne.24661] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 01/05/2019] [Accepted: 02/01/2019] [Indexed: 12/12/2022]
Abstract
At mammalian neuromuscular junctions (NMJs), prolonged inactivity leads to muscle denervation and atrophy. By contrast, amphibian NMJs do not show such degeneration even though they can remain in a state of drought-imposed dormancy (hibernation) for many years. We have previously reported that during the dry season, toad (Bufo marinus) NMJs display decreased sensitivity to extracellular calcium-dependent neurotransmitter release, which leads to minimal neuromuscular transmission. In the present study, we examined and compared NMJ morphology of toads obtained from the wild during the wet season (February-March) when these toads are active, to toads obtained from dry season (October-November) when toads are inactive. Iliofibularis muscles were isolated and prepared for immunostaining with anti-SV2, a monoclonal antibody that labels synaptic vesicle glycoprotein SV2. The corresponding postsynaptic acetylcholine receptors were stained using Alexa Fluro-555 conjugated α-bungarotoxin. Confocal microscopy and three-dimensional reconstructions were then used to examine the pre-and postsynaptic morphology of toads NMJs from the dry (inactive) and wet (active) seasons. Total axon branch number, the percentage of axon branches with discontinuous distributions of synaptic vesicles, and further the Pearson value of colocalization of pre and postsynaptic elements in each NMJs from both the dry and wet season were compared. While our previous studies on dry toads revealed a significant reduction in evoked neurotransmission, our present findings show that the structure of the NMJs suffered limited level of remodeling, suggesting a mechanism utilized by NMJs in dry season toads to support quick recover from their dormant state after the heavy rain in wet season.
Collapse
Affiliation(s)
- Dengyun Ge
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Queensland, Australia
| | - Peter G Noakes
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Queensland, Australia.,Queensland Brain Institute, The University of Queensland, Queensland, Australia
| | - Nickolas A Lavidis
- Faculty of Medicine, School of Biomedical Sciences, The University of Queensland, Queensland, Australia
| |
Collapse
|
15
|
Lee JD, Levin SC, Willis EF, Li R, Woodruff TM, Noakes PG. Complement components are upregulated and correlate with disease progression in the TDP-43 Q331K mouse model of amyotrophic lateral sclerosis. J Neuroinflammation 2018; 15:171. [PMID: 29859100 PMCID: PMC5984816 DOI: 10.1186/s12974-018-1217-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 05/24/2018] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Components of the innate immune complement system have been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS) specifically using hSOD1 transgenic animals; however, a comprehensive examination of complement expression in other transgenic ALS models has not been performed. This study therefore aimed to determine the expression of several key complement components and regulators in the lumbar spinal cord and tibialis anterior muscle of TDP-43Q331K mice during different disease ages. METHODS Non-transgenic, TDP-43WT and TDP-43Q331K mice were examined at three different ages of disease progression. Expression of complement components and their regulators were examined using real-time quantitative PCR and enzyme-linked immunosorbent assay. Localisation of terminal complement component receptor C5aR1 within the lumbar spinal cord was also investigated using immunohistochemistry. RESULTS Altered levels of several major complement factors, including C5a, in the spinal cord and tibialis anterior muscle of TDP-43Q331K mice were observed as disease progressed, suggesting overall increased complement activation in TDP-43Q331K mice. C5aR1 increased during disease progression, with immuno-localisation demonstrating expression on motor neurons and expression on microglia surrounding the regions of motor neuron death. There was a strong negative linear relationship between spinal cord C1qB, C3 and C5aR1 mRNA levels with hind-limb grip strength. CONCLUSIONS These results indicate that similar to SOD1 transgenic animals, local complement activation and increased expression of C5aR1 may contribute to motor neuron death and neuromuscular junction denervation in the TDP-43Q331K mouse ALS model. This further validates C5aR1 as a potential therapeutic target for ALS.
Collapse
Affiliation(s)
- John D. Lee
- School of Biomedical Sciences, the University of Queensland, St Lucia, Brisbane, QLD 4072 Australia
- University of Queensland Centre for Clinical Research, the University of Queensland, Herston, Brisbane, QLD 4029 Australia
| | - Samantha C. Levin
- School of Biomedical Sciences, the University of Queensland, St Lucia, Brisbane, QLD 4072 Australia
| | - Emily F. Willis
- School of Biomedical Sciences, the University of Queensland, St Lucia, Brisbane, QLD 4072 Australia
| | - Rui Li
- School of Biomedical Sciences, the University of Queensland, St Lucia, Brisbane, QLD 4072 Australia
| | - Trent M. Woodruff
- School of Biomedical Sciences, the University of Queensland, St Lucia, Brisbane, QLD 4072 Australia
| | - Peter G. Noakes
- School of Biomedical Sciences, the University of Queensland, St Lucia, Brisbane, QLD 4072 Australia
- Queensland Brain Institute, the University of Queensland, St Lucia, Brisbane, QLD 4072 Australia
| |
Collapse
|
16
|
Chand KK, Lee KM, Lee JD, Qiu H, Willis EF, Lavidis NA, Hilliard MA, Noakes PG. Defects in synaptic transmission at the neuromuscular junction precede motor deficits in a TDP‐43
Q331K
transgenic mouse model of amyotrophic lateral sclerosis. FASEB J 2018; 32:2676-2689. [DOI: 10.1096/fj.201700835r] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Kirat K. Chand
- School of Biomedical Sciences Brisbane Queensland Australia
| | - Kah Meng Lee
- School of Biomedical Sciences Brisbane Queensland Australia
| | - John D. Lee
- School of Biomedical Sciences Brisbane Queensland Australia
| | - Hao Qiu
- School of Biomedical Sciences Brisbane Queensland Australia
| | | | | | | | | |
Collapse
|
17
|
Klenowski PM, Wright SE, Mu EWH, Noakes PG, Lavidis NA, Bartlett SE, Bellingham MC, Fogarty MJ. Investigating Methodological Differences in the Assessment of Dendritic Morphology of Basolateral Amygdala Principal Neurons-A Comparison of Golgi-Cox and Neurobiotin Electroporation Techniques. Brain Sci 2017; 7:brainsci7120165. [PMID: 29257086 PMCID: PMC5742768 DOI: 10.3390/brainsci7120165] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 12/15/2017] [Accepted: 12/16/2017] [Indexed: 11/28/2022] Open
Abstract
Quantitative assessments of neuronal subtypes in numerous brain regions show large variations in dendritic arbor size. A critical experimental factor is the method used to visualize neurons. We chose to investigate quantitative differences in basolateral amygdala (BLA) principal neuron morphology using two of the most common visualization methods: Golgi–Cox staining and neurobiotin (NB) filling. We show in 8-week-old Wistar rats that NB-filling reveals significantly larger dendritic arbors and different spine densities, compared to Golgi–Cox-stained BLA neurons. Our results demonstrate important differences and provide methodological insights into quantitative disparities of BLA principal neuron morphology reported in the literature.
Collapse
Affiliation(s)
- Paul M Klenowski
- Translational Research Institute, Queensland University of Technology, Brisbane 4102, Australia.
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
| | - Sophie E Wright
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia.
| | - Erica W H Mu
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia.
| | - Peter G Noakes
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia.
- Queensland Brain Institute, the University of Queensland, Brisbane 4072, Australia.
| | - Nickolas A Lavidis
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia.
| | - Selena E Bartlett
- Translational Research Institute, Queensland University of Technology, Brisbane 4102, Australia.
| | - Mark C Bellingham
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia.
| | - Matthew J Fogarty
- School of Biomedical Sciences, The University of Queensland, Brisbane 4072, Australia.
- Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
| |
Collapse
|
18
|
Lee KM, Chand KK, Hammond LA, Lavidis NA, Noakes PG. Functional decline at the aging neuromuscular junction is associated with altered laminin-α4 expression. Aging (Albany NY) 2017; 9:880-899. [PMID: 28301326 PMCID: PMC5391237 DOI: 10.18632/aging.101198] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 03/03/2017] [Indexed: 12/04/2022]
Abstract
Laminin-α4 is involved in the alignment of active zones to postjunctional folds at the neuromuscular junction (NMJ). Prior study has implicated laminin-α4 in NMJ maintenance, with altered NMJ morphology observed in adult laminin-α4 deficient mice (lama4−/−). The present study further investigated the role of laminin-α4 in NMJ maintenance by functional characterization of transmission properties, morphological investigation of synaptic proteins including synaptic laminin-α4, and neuromotor behavioral testing. Results showed maintained perturbed transmission properties at lama4−/− NMJs from adult (3 months) through to aged (18-22 months). Hind-limb grip force demonstrated similar trends as transmission properties, with maintained weaker grip force across age groups in lama4−/−. Interestingly, both transmission properties and hind-limb grip force in aged wild-types resembled those observed in adult lama4−/−. Most significantly, altered expression of laminin-α4 was noted at the wild-type NMJs prior to the observed decline in transmission properties, suggesting that altered laminin-α4 expression precedes the decline of neurotransmission in aging wild-types. These findings significantly support the role of laminin-α4 in maintenance of the NMJ during aging.
Collapse
Affiliation(s)
- Kah Meng Lee
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Kirat K Chand
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia.,University of Queensland Centre for Clinical Research, The University of Queensland, Herston, Queensland 4029, Australia
| | - Luke A Hammond
- Queensland Brain Institute, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Nickolas A Lavidis
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia
| | - Peter G Noakes
- School of Biomedical Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia.,Queensland Brain Institute, The University of Queensland, St. Lucia, Queensland 4072, Australia
| |
Collapse
|
19
|
Fogarty MJ, Mu EWH, Lavidis NA, Noakes PG, Bellingham MC. Motor Areas Show Altered Dendritic Structure in an Amyotrophic Lateral Sclerosis Mouse Model. Front Neurosci 2017; 11:609. [PMID: 29163013 PMCID: PMC5672020 DOI: 10.3389/fnins.2017.00609] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 10/18/2017] [Indexed: 12/11/2022] Open
Abstract
Objective: Motor neurons (MNs) die in amyotrophic lateral sclerosis (ALS), a clinically heterogeneous neurodegenerative disease of unknown etiology. In human or rodent studies, MN loss is preceded by increased excitability. As increased neuronal excitability correlates with structural changes in dendritic arbors and spines, we have examined longitudinal changes in dendritic structure in vulnerable neuron populations in a mouse model of familial ALS. Methods: We used a modified Golgi-Cox staining method to determine the progressive changes in dendritic structure of hippocampal CA1 pyramidal neurons, striatal medium spiny neurons, and resistant (trochlear, IV) or susceptible (hypoglossal, XII; lumbar) MNs from brainstem and spinal cord of mice over-expressing the human SOD1G93A (SOD1) mutation, in comparison to wild-type (WT) mice, at four postnatal (P) ages of 8–15, 28–35, 65–75, and 120 days. Results: In SOD1 mice, dendritic changes occur at pre-symptomatic ages in both XII and spinal cord lumbar MNs. Spine loss without dendritic changes was present in striatal neurons from disease onset. Spine density increases were present at all ages studied in SOD1 XII MNs. Spine density increased in neonatal lumbar MNs, before decreasing to control levels by P28-35 and was decreased by P120. SOD1 XII MNs and lumbar MNs, but not trochlear MNs showed vacuolization from the same time-points. Trochlear MN dendrites were unchanged. Interpretation: Dendritic structure and spine alterations correlate with the neuro-motor phenotype in ALS and with cognitive and extra-motor symptoms seen in patients. Prominent early changes in dendritic arbors and spines occur in susceptible cranial and spinal cord MNs, but are absent in MNs resistant to loss in ALS.
Collapse
Affiliation(s)
- Matthew J Fogarty
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland, St Lucia, QLD, Australia
| | - Erica W H Mu
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland, St Lucia, QLD, Australia
| | - Nickolas A Lavidis
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland, St Lucia, QLD, Australia
| | - Peter G Noakes
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland, St Lucia, QLD, Australia.,Queensland Brain Institute, University of Queensland, St Lucia, QLD, Australia
| | - Mark C Bellingham
- Faculty of Medicine, School of Biomedical Sciences, University of Queensland, St Lucia, QLD, Australia
| |
Collapse
|
20
|
Quek H, Luff J, Cheung K, Kozlov S, Gatei M, Lee CS, Bellingham MC, Noakes PG, Lim YC, Barnett NL, Dingwall S, Wolvetang E, Mashimo T, Roberts TL, Lavin MF. A rat model of ataxia-telangiectasia: evidence for a neurodegenerative phenotype. Hum Mol Genet 2017; 26:109-123. [PMID: 28007901 DOI: 10.1093/hmg/ddw371] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Accepted: 10/25/2016] [Indexed: 11/14/2022] Open
Abstract
Ataxia-telangiectasia (A-T), an autosomal recessive disease caused by mutations in the ATM gene is characterised by cerebellar atrophy and progressive neurodegeneration which has been poorly recapitulated in Atm mutant mice. Consequently, pathways leading to neurodegeneration in A-T are poorly understood. We describe here the generation of an Atm knockout rat model that does not display cerebellar atrophy but instead paralysis and spinal cord atrophy, reminiscent of that seen in older patients and milder forms of the disorder. Loss of Atm in neurons and glia leads to accumulation of cytosolic DNA, increased cytokine production and constitutive activation of microglia consistent with a neuroinflammatory phenotype. Rats lacking ATM had significant loss of motor neurons and microgliosis in the spinal cord, consistent with onset of paralysis. Since short term treatment with steroids has been shown to improve the neurological signs in A-T patients we determined if that was also the case for Atm-deficient rats. Betamethasone treatment extended the lifespan of Atm knockout rats, prevented microglial activation and significantly decreased neuroinflammatory changes and motor neuron loss. These results point to unrepaired damage to DNA leading to significant levels of cytosolic DNA in Atm-deficient neurons and microglia and as a consequence activation of the cGAS-STING pathway and cytokine production. This in turn would increase the inflammatory microenvironment leading to dysfunction and death of neurons. Thus the rat model represents a suitable one for studying neurodegeneration in A-T and adds support for the use of anti-inflammatory drugs for the treatment of neurodegeneration in A-T patients.
Collapse
Affiliation(s)
- Hazel Quek
- The University of Queensland Centre for Clinical Research, Herston, Qld, Australia.,QIMR Berghofer Medical Research Institute, Herston, Qld, Australia
| | - John Luff
- The University of Queensland Centre for Clinical Research, Herston, Qld, Australia
| | - KaGeen Cheung
- The University of Queensland Centre for Clinical Research, Herston, Qld, Australia.,QIMR Berghofer Medical Research Institute, Herston, Qld, Australia
| | - Sergei Kozlov
- The University of Queensland Centre for Clinical Research, Herston, Qld, Australia
| | - Magtouf Gatei
- The University of Queensland Centre for Clinical Research, Herston, Qld, Australia
| | - C Soon Lee
- The Ingham Institute for Applied Medical Research and School of Medicine, Western Sydney University, Liverpool, NSW, Australia
| | - Mark C Bellingham
- School of Biomedical Sciences, The University of Queensland, St Lucia, Qld, Australia
| | - Peter G Noakes
- School of Biomedical Sciences, The University of Queensland, St Lucia, Qld, Australia
| | - Yi Chieh Lim
- QIMR Berghofer Medical Research Institute, Herston, Qld, Australia
| | - Nigel L Barnett
- The University of Queensland Centre for Clinical Research, Herston, Qld, Australia.,Queensland Eye Institute, South Brisbane, Qld, Australia.,School of Biomedical Sciences, Queensland University of Technology, Brisbane, Qld, Australia
| | - Steven Dingwall
- The University of Queensland Centre for Clinical Research, Herston, Qld, Australia.,QIMR Berghofer Medical Research Institute, Herston, Qld, Australia.,Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Qld, Australia
| | - Ernst Wolvetang
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, Qld, Australia
| | - Tomoji Mashimo
- Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Tara L Roberts
- The University of Queensland Centre for Clinical Research, Herston, Qld, Australia.,QIMR Berghofer Medical Research Institute, Herston, Qld, Australia.,The Ingham Institute for Applied Medical Research and School of Medicine, Western Sydney University, Liverpool, NSW, Australia
| | - Martin F Lavin
- The University of Queensland Centre for Clinical Research, Herston, Qld, Australia
| |
Collapse
|
21
|
Lee JD, Kumar V, Fung JNT, Ruitenberg MJ, Noakes PG, Woodruff TM. Pharmacological inhibition of complement C5a-C5a 1 receptor signalling ameliorates disease pathology in the hSOD1 G93A mouse model of amyotrophic lateral sclerosis. Br J Pharmacol 2017; 174:689-699. [PMID: 28128456 DOI: 10.1111/bph.13730] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 01/24/2017] [Accepted: 01/25/2017] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND AND PURPOSE Amyotrophic lateral sclerosis (ALS) is a fatal and rapidly progressing motor neuron disease without effective treatment. The complement system is up-regulated in ALS, with recent studies indicating that the activation product C5a accelerates disease progression via the C5a1 receptor (C5aR1). We therefore examined the therapeutic effect of C5a1 receptor antagonism in hSOD1G93A mice, the most widely used preclinical model of ALS. EXPERIMENTAL APPROACH The selective and orally active C5a1 receptor antagonist, PMX205, was administered to hSOD1G93A mice in drinking water, both pre- and post-disease onset. Blood, brain and spinal cord pharmacokinetics were performed using LC-MS/MS methods. Effects of PMX205 on hSOD1G93A disease progression was determined using body weight, hindlimb grip strength, survival time and blood analysis. KEY RESULTS PMX205 entered the intact CNS at pharmacologically active concentrations, with increased entry observed in hSOD1G93A mice as the disease progressed, in line with augmented blood-brain barrier breakdown. hSOD1G93A mice treated with PMX205 before disease onset had significantly improved hindlimb grip strength, slower disease progression and extended survival, compared with vehicle treatment. These improvements were associated with reductions in pro-inflammatory monocytes and granulocytes and increases in T-helper lymphocytes in peripheral blood. PMX205 treatment beginning 3 weeks following disease onset also attenuated disease progression, significantly extending survival. CONCLUSION AND IMPLICATIONS These results confirm that C5a1 receptors play a pathogenic role in hSOD1G93A mice, further validating the C5a-C5a1 receptor signalling axis as a potential therapeutic target to slow disease progression in ALS.
Collapse
Affiliation(s)
- John D Lee
- School of Biomedical Sciences, The University of Queensland, Brisbane, Qld, Australia.,University of Queensland Centre for Clinical Research, The University of Queensland, Brisbane, Qld, Australia
| | - Vinod Kumar
- School of Biomedical Sciences, The University of Queensland, Brisbane, Qld, Australia
| | - Jenny N T Fung
- School of Biomedical Sciences, The University of Queensland, Brisbane, Qld, Australia
| | - Marc J Ruitenberg
- School of Biomedical Sciences, The University of Queensland, Brisbane, Qld, Australia.,Queensland Brain Institute, The University of Queensland, Brisbane, Qld, Australia.,Trauma, Critical Care and Recovery, Brisbane Diamantina Health Partners, The University of Queensland, Brisbane, Qld, Australia
| | - Peter G Noakes
- School of Biomedical Sciences, The University of Queensland, Brisbane, Qld, Australia.,Queensland Brain Institute, The University of Queensland, Brisbane, Qld, Australia
| | - Trent M Woodruff
- School of Biomedical Sciences, The University of Queensland, Brisbane, Qld, Australia
| |
Collapse
|
22
|
Chand KK, Lee KM, Lavidis NA, Noakes PG. Loss of laminin‐a4 results in pre‐ and postsynaptic modifications at the neuromuscular junction. FASEB J 2016; 31:1323-1336. [DOI: 10.1096/fj.201600899r] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 12/06/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Kirat K. Chand
- School of Biomedical Sciences St. Lucia Queensland Australia
| | - Kah Meng Lee
- School of Biomedical Sciences St. Lucia Queensland Australia
| | | | - Peter G. Noakes
- School of Biomedical Sciences St. Lucia Queensland Australia
- Queensland Brain InstituteThe University of Queensland St. Lucia Queensland Australia
| |
Collapse
|
23
|
Quek H, Luff J, Cheung K, Kozlov S, Gatei M, Lee CS, Bellingham MC, Noakes PG, Lim YC, Barnett NL, Dingwall S, Wolvetang E, Mashimo T, Roberts TL, Lavin MF. Rats with a missense mutation in Atm display neuroinflammation and neurodegeneration subsequent to accumulation of cytosolic DNA following unrepaired DNA damage. J Leukoc Biol 2016; 101:927-947. [PMID: 27895165 DOI: 10.1189/jlb.4vma0716-316r] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 10/14/2016] [Accepted: 10/25/2016] [Indexed: 11/24/2022] Open
Abstract
Mutations in the ataxia-telangiectasia (A-T)-mutated (ATM) gene give rise to the human genetic disorder A-T, characterized by immunodeficiency, cancer predisposition, and neurodegeneration. Whereas a series of animal models recapitulate much of the A-T phenotype, they fail to present with ataxia or neurodegeneration. We describe here the generation of an Atm missense mutant [amino acid change of leucine (L) to proline (P) at position 2262 (L2262P)] rat by intracytoplasmic injection (ICSI) of mutant sperm into oocytes. Atm-mutant rats (AtmL2262P/L2262P ) expressed low levels of ATM protein, suggesting a destabilizing effect of the mutation, and had a significantly reduced lifespan compared with Atm+/+ Whereas these rats did not show cerebellar atrophy, they succumbed to hind-limb paralysis (45%), and the remainder developed tumors. Closer examination revealed the presence of both dsDNA and ssDNA in the cytoplasm of cells in the hippocampus, cerebellum, and spinal cord of AtmL2262P/L2262P rats. Significantly increased levels of IFN-β and IL-1β in all 3 tissues were indicative of DNA damage induction of the type 1 IFN response. This was further supported by NF-κB activation, as evidenced by p65 phosphorylation (P65) and translocation to the nucleus in the spinal cord and parahippocampus. Other evidence of neuroinflammation in the brain and spinal cord was the loss of motor neurons and the presence of increased activation of microglia. These data provide support for a proinflammatory phenotype that is manifested in the Atm mutant rat as hind-limb paralysis. This mutant represents a useful model to investigate the importance of neuroinflammation in A-T.
Collapse
Affiliation(s)
- Hazel Quek
- University of Queensland Centre for Clinical Research, Herston, Queensland, Australia.,Queensland Institute of Medical Research Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - John Luff
- University of Queensland Centre for Clinical Research, Herston, Queensland, Australia
| | - KaGeen Cheung
- University of Queensland Centre for Clinical Research, Herston, Queensland, Australia.,Queensland Institute of Medical Research Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Sergei Kozlov
- University of Queensland Centre for Clinical Research, Herston, Queensland, Australia
| | - Magtouf Gatei
- University of Queensland Centre for Clinical Research, Herston, Queensland, Australia
| | - C Soon Lee
- Ingham Institute for Applied Medical Research and School of Medicine, Western Sydney University, Liverpool, New South Wales, Australia
| | - Mark C Bellingham
- School of Biomedical Sciences, University of Queensland, St Lucia, Queensland, Australia
| | - Peter G Noakes
- School of Biomedical Sciences, University of Queensland, St Lucia, Queensland, Australia
| | - Yi Chieh Lim
- Queensland Institute of Medical Research Berghofer Medical Research Institute, Herston, Queensland, Australia
| | - Nigel L Barnett
- University of Queensland Centre for Clinical Research, Herston, Queensland, Australia.,Queensland Eye Institute, South Brisbane, Queensland, Australia.,School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Steven Dingwall
- University of Queensland Centre for Clinical Research, Herston, Queensland, Australia.,Queensland Institute of Medical Research Berghofer Medical Research Institute, Herston, Queensland, Australia.,Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Queensland, Australia; and
| | - Ernst Wolvetang
- Australian Institute for Bioengineering and Nanotechnology, University of Queensland, St Lucia, Queensland, Australia; and
| | - Tomoji Mashimo
- Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Tara L Roberts
- University of Queensland Centre for Clinical Research, Herston, Queensland, Australia; .,Queensland Institute of Medical Research Berghofer Medical Research Institute, Herston, Queensland, Australia.,Ingham Institute for Applied Medical Research and School of Medicine, Western Sydney University, Liverpool, New South Wales, Australia
| | - Martin F Lavin
- University of Queensland Centre for Clinical Research, Herston, Queensland, Australia;
| |
Collapse
|
24
|
Fogarty MJ, Mu EWH, Noakes PG, Lavidis NA, Bellingham MC. Marked changes in dendritic structure and spine density precede significant neuronal death in vulnerable cortical pyramidal neuron populations in the SOD1(G93A) mouse model of amyotrophic lateral sclerosis. Acta Neuropathol Commun 2016; 4:77. [PMID: 27488828 PMCID: PMC4973034 DOI: 10.1186/s40478-016-0347-y] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 07/12/2016] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is characterised by the death of upper (corticospinal) and lower motor neurons (MNs) with progressive muscle weakness. This incurable disease is clinically heterogeneous and its aetiology remains unknown. Increased excitability of corticospinal MNs has been observed prior to symptoms in human and rodent studies. Increased excitability has been correlated with structural changes in neuronal dendritic arbors and spines for decades. Here, using a modified Golgi-Cox staining method, we have made the first longitudinal study examining the dendrites of pyramidal neurons from the motor cortex, medial pre-frontal cortex, somatosensory cortex and entorhinal cortex of hSOD1G93A (SOD1) mice compared to wild-type (WT) littermate controls at postnatal (P) days 8–15, 28–35, 65–75 and 120. Progressive decreases in dendritic length and spine density commencing at pre-symptomatic ages (P8-15 or P28-35) were observed in layer V pyramidal neurons within the motor cortex and medial pre-frontal cortex of SOD1 mice compared to WT mice. Spine loss without concurrent dendritic pathology was present in the pyramidal neurons of the somatosensory cortex from disease-onset (P65-75). Our results from the SOD1 model suggest that dendritic and dendritic spine changes foreshadow and underpin the neuromotor phenotypes present in ALS and may contribute to the varied cognitive, executive function and extra-motor symptoms commonly seen in ALS patients. Determining if these phenomena are compensatory or maladaptive may help explain differential susceptibility of neurons to degeneration in ALS.
Collapse
|
25
|
Chand KK, Lee KM, Lavidis NA, Rodriguez-Valle M, Ijaz H, Koehbach J, Clark RJ, Lew-Tabor A, Noakes PG. Tick holocyclotoxins trigger host paralysis by presynaptic inhibition. Sci Rep 2016; 6:29446. [PMID: 27389875 PMCID: PMC4937380 DOI: 10.1038/srep29446] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 06/20/2016] [Indexed: 11/25/2022] Open
Abstract
Ticks are important vectors of pathogens and secreted neurotoxins with approximately 69 out of 692 tick species having the ability to induce severe toxicoses in their hosts. The Australian paralysis tick (Ixodes holocyclus) is known to be one of the most virulent tick species producing a flaccid paralysis and fatalities caused by a family of neurotoxins known as holocyclotoxins (HTs). The paralysis mechanism of these toxins is temperature dependent and is thought to involve inhibition of acetylcholine levels at the neuromuscular junction. However, the target and mechanism of this inhibition remain uncharacterised. Here, we report that three members of the holocyclotoxin family; HT-1 (GenBank AY766147), HT-3 (GenBank KP096303) and HT-12 (GenBank KP963967) induce muscle paralysis by inhibiting the dependence of transmitter release on extracellular calcium. Previous study was conducted using extracts from tick salivary glands, while the present study is the first to use pure toxins from I. holocyclus. Our findings provide greater insight into the mechanisms by which these toxins act to induce paralysis.
Collapse
Affiliation(s)
- Kirat K Chand
- School of Biomedical Sciences, The University of Queensland, St Lucia, 4067, Australia
| | - Kah Meng Lee
- School of Biomedical Sciences, The University of Queensland, St Lucia, 4067, Australia
| | - Nickolas A Lavidis
- School of Biomedical Sciences, The University of Queensland, St Lucia, 4067, Australia
| | - Manuel Rodriguez-Valle
- Queensland Alliance for Agriculture &Food Innovation, The University of Queensland, QLD, Australia
| | - Hina Ijaz
- School of Biomedical Sciences, The University of Queensland, St Lucia, 4067, Australia
| | - Johannes Koehbach
- School of Biomedical Sciences, The University of Queensland, St Lucia, 4067, Australia
| | - Richard J Clark
- School of Biomedical Sciences, The University of Queensland, St Lucia, 4067, Australia
| | - Ala Lew-Tabor
- Queensland Alliance for Agriculture &Food Innovation, The University of Queensland, QLD, Australia.,Centre for Comparative Genomics, Murdoch University, Perth, WA 6150, Australia
| | - Peter G Noakes
- School of Biomedical Sciences, The University of Queensland, St Lucia, 4067, Australia
| |
Collapse
|
26
|
Kanjhan R, Fogarty MJ, Noakes PG, Bellingham MC. Developmental changes in the morphology of mouse hypoglossal motor neurons. Brain Struct Funct 2015; 221:3755-86. [PMID: 26476929 PMCID: PMC5009180 DOI: 10.1007/s00429-015-1130-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 10/03/2015] [Indexed: 12/19/2022]
Abstract
Hypoglossal motor neurons (XII MNs) innervate tongue muscles important in breathing, suckling and vocalization. Morphological properties of 103 XII MNs were studied using Neurobiotin™ filling in transverse brainstem slices from C57/Bl6 mice (n = 34) from embryonic day (E) 17 to postnatal day (P) 28. XII MNs from areas thought to innervate different tongue muscles showed similar morphology in most, but not all, features. Morphological properties of XII MNs were established prior to birth, not differing between E17–18 and P0. MN somatic volume gradually increased for the first 2 weeks post-birth. The complexity of dendritic branching and dendrite length of XII MNs increased throughout development (E17–P28). MNs in the ventromedial XII motor nucleus, likely to innervate the genioglossus, frequently (42 %) had dendrites crossing to the contralateral side at all ages, but their number declined with postnatal development. Unexpectedly, putative dendritic spines were found in all XII MNs at all ages, and were primarily localized to XII MN somata and primary dendrites at E18–P4, increased in distal dendrites by P5–P8, and were later predominantly found in distal dendrites. Dye-coupling between XII MNs was common from E18 to P7, but declined strongly with maturation after P7. Axon collaterals were found in 20 % (6 of 28) of XII MNs with filled axons; collaterals terminated widely outside and, in one case, within the XII motor nucleus. These results reveal new morphological features of mouse XII MNs, and suggest that dendritic projection patterns, spine density and distribution, and dye-coupling patterns show specific developmental changes in mice.
Collapse
Affiliation(s)
- Refik Kanjhan
- School of Biomedical Sciences, University of Queensland, Brisbane, QLD, 4072, Australia
| | - Matthew J Fogarty
- School of Biomedical Sciences, University of Queensland, Brisbane, QLD, 4072, Australia
| | - Peter G Noakes
- School of Biomedical Sciences, University of Queensland, Brisbane, QLD, 4072, Australia.,Queensland Brain Institute, University of Queensland, Brisbane, QLD, 4072, Australia
| | - Mark C Bellingham
- School of Biomedical Sciences, University of Queensland, Brisbane, QLD, 4072, Australia.
| |
Collapse
|
27
|
Klenowski PM, Fogarty MJ, Belmer A, Noakes PG, Bellingham MC, Bartlett SE. Structural and functional characterization of dendritic arbors and GABAergic synaptic inputs on interneurons and principal cells in the rat basolateral amygdala. J Neurophysiol 2015; 114:942-57. [PMID: 26041829 DOI: 10.1152/jn.00824.2014] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 06/02/2015] [Indexed: 11/22/2022] Open
Abstract
The basolateral amygdala (BLA) is a complex brain region associated with processing emotional states, such as fear, anxiety, and stress. Some aspects of these emotional states are driven by the network activity of synaptic connections, derived from both local circuitry and projections to the BLA from other regions. Although the synaptic physiology and general morphological characteristics are known for many individual cell types within the BLA, the combination of morphological, electrophysiological, and distribution of neurochemical GABAergic synapses in a three-dimensional neuronal arbor has not been reported for single neurons from this region. The aim of this study was to assess differences in morphological characteristics of BLA principal cells and interneurons, quantify the distribution of GABAergic neurochemical synapses within the entire neuronal arbor of each cell type, and determine whether GABAergic synaptic density correlates with electrophysiological recordings of inhibitory postsynaptic currents. We show that BLA principal neurons form complex dendritic arborizations, with proximal dendrites having fewer spines but higher densities of neurochemical GABAergic synapses compared with distal dendrites. Furthermore, we found that BLA interneurons exhibited reduced dendritic arbor lengths and spine densities but had significantly higher densities of putative GABAergic synapses compared with principal cells, which was correlated with an increased frequency of spontaneous inhibitory postsynaptic currents. The quantification of GABAergic connectivity, in combination with morphological and electrophysiological measurements of the BLA cell types, is the first step toward a greater understanding of how fear and stress lead to changes in morphology, local connectivity, and/or synaptic reorganization of the BLA.
Collapse
Affiliation(s)
- Paul M Klenowski
- Translational Research Institute and Institute for Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Matthew J Fogarty
- School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia; and
| | - Arnauld Belmer
- Translational Research Institute and Institute for Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Peter G Noakes
- School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia; and Queensland Brain Institute, The University of Queensland, Brisbane, Queensland, Australia
| | - Mark C Bellingham
- School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia; and
| | - Selena E Bartlett
- Translational Research Institute and Institute for Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia;
| |
Collapse
|
28
|
Mantovani S, Gordon R, Macmaw JK, Pfluger CMM, Henderson RD, Noakes PG, McCombe PA, Woodruff TM. Elevation of the terminal complement activation products C5a and C5b-9 in ALS patient blood. J Neuroimmunol 2015; 276:213-8. [PMID: 25262158 DOI: 10.1016/j.jneuroim.2014.09.005] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 09/05/2014] [Accepted: 09/08/2014] [Indexed: 10/24/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease, characterized by the progressive loss of motor neurons within the central nervous system. Neural degeneration and inflammatory processes, including activation of the complement system are hallmarks of this pathology. Our past work in ALS animal models (hSOD1 G93A rodents) has revealed that blockade of the receptor for complement activation fragment C5a (C5aR), improves ALS-like symptoms and extends survival. We now show that the levels of C5a and C5b-9, but not C3a nor C4a, are significantly elevated in plasma from ALS patients compared to healthy controls. C5a was also elevated within leukocytes from ALS patients suggesting heightened C5a receptor interaction. Overall, these findings indicate that there is enhanced peripheral immune complement terminal pathway activation in ALS, which may have relevance in the disease process.
Collapse
Affiliation(s)
- S Mantovani
- School of Biomedical Sciences, University of Queensland, St. Lucia, Queensland 4072, Australia
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Chand KK, Lee KM, Schenning MP, Lavidis NA, Noakes PG. Loss of β2-laminin alters calcium sensitivity and voltage-gated calcium channel maturation of neurotransmission at the neuromuscular junction. J Physiol 2014; 593:245-65. [PMID: 25556799 DOI: 10.1113/jphysiol.2014.284133] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 10/23/2014] [Indexed: 12/16/2022] Open
Abstract
KEY POINTS Neuromuscular junctions from β2-laminin-deficient mice exhibit lower levels of calcium sensitivity. Loss of β2-laminin leads to a failure in switching from N- to P/Q-type voltage-gated calcium channel (VGCC)-mediated transmitter release that normally occurs with neuromuscular junction maturation. The motor nerve terminals from β2-laminin-deficient mice fail to up-regulate the expression of P/Q-type VGCCs clusters and down-regulate N-type VGCCs clusters, as they mature. There is decreased co-localisation of presynaptic specialisations in β2-laminin-deficient neuromuscular junctions as a consequence of lesser P/Q-type VGCC expression. These findings support the idea that β2-laminin is critical in the organisation and maintenance of active zones at the neuromuscular junction via its interaction with P/Q-type VGCCs, which aid in stabilisation of the synapse. β2-laminin is a key mediator in the differentiation and formation of the skeletal neuromuscular junction. Loss of β2-laminin results in significant structural and functional aberrations such as decreased number of active zones and reduced spontaneous release of transmitter. In vitro β2-laminin has been shown to bind directly to the pore forming subunit of P/Q-type voltage-gated calcium channels (VGCCs). Neurotransmission is initially mediated by N-type VGCCs, but by postnatal day 18 switches to P/Q-type VGCC dominance. The present study investigated the changes in neurotransmission during the switch from N- to P/Q-type VGCC-mediated transmitter release at β2-laminin-deficient junctions. Analysis of the relationship between quantal content and extracellular calcium concentrations demonstrated a decrease in the calcium sensitivity, but no change in calcium dependence at β2-laminin-deficient junctions. Electrophysiological studies on VGCC sub-types involved in transmitter release indicate N-type VGCCs remain the primary mediator of transmitter release at matured β2-laminin-deficient junctions. Immunohistochemical analyses displayed irregularly shaped and immature β2-laminin-deficient neuromuscular junctions when compared to matured wild-type junctions. β2-laminin-deficient junctions also maintained the presence of N-type VGCC clustering within the presynaptic membrane, which supported the functional findings of the present study. We conclude that β2-laminin is a key regulator in development of the NMJ, with its loss resulting in reduced transmitter release due to decreased calcium sensitivity stemming from a failure to switch from N- to P/Q-type VGCC-mediated synaptic transmission.
Collapse
Affiliation(s)
- Kirat K Chand
- School of Biomedical Sciences, The University of Queensland, St Lucia, 4067, Australia
| | | | | | | | | |
Collapse
|
30
|
Fogarty MJ, Hammond LA, Kanjhan R, Bellingham MC, Noakes PG. A method for the three-dimensional reconstruction of Neurobiotin™-filled neurons and the location of their synaptic inputs. Front Neural Circuits 2013; 7:153. [PMID: 24101895 PMCID: PMC3787200 DOI: 10.3389/fncir.2013.00153] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 09/12/2013] [Indexed: 12/15/2022] Open
Abstract
Here, we describe a robust method for mapping the number and type of neuro-chemically distinct synaptic inputs that a single reconstructed neuron receives. We have used individual hypoglossal motor neurons filled with Neurobiotin by semi-loose seal electroporation in thick brainstem slices. These filled motor neurons were then processed for excitatory and inhibitory synaptic inputs, using immunohistochemical-labeling procedures. For excitatory synapses, we used anti-VGLUT2 to locate glutamatergic pre-synaptic terminals and anti-PSD-95 to locate post-synaptic specializations on and within the surface of these filled motor neurons. For inhibitory synapses, we used anti-VGAT to locate GABAergic pre-synaptic terminals and anti-GABA-A receptor subunit α1 to locate the post-synaptic domain. The Neurobiotin-filled and immuno-labeled motor neuron was then processed for optical sectioning using confocal microscopy. The morphology of the motor neuron including its dendritic tree and the distribution of excitatory and inhibitory synapses were then determined by three-dimensional reconstruction using IMARIS software (Bitplane). Using surface rendering, fluorescence thresholding, and masking of unwanted immuno-labeling, tools found in IMARIS, we were able to obtain an accurate 3D structure of an individual neuron including the number and location of its glutamatergic and GABAergic synaptic inputs. The power of this method allows for a rapid morphological confirmation of the post-synaptic responses recorded by patch-clamp prior to Neurobiotin filling. Finally, we show that this method can be adapted to super-resolution microscopy techniques, which will enhance its applicability to the study of neural circuits at the level of synapses.
Collapse
Affiliation(s)
- Matthew J Fogarty
- School of Biomedical Sciences, The University of Queensland Brisbane, QLD, Australia
| | | | | | | | | |
Collapse
|
31
|
Lee JD, Kamaruzaman NA, Fung JNT, Taylor SM, Turner BJ, Atkin JD, Woodruff TM, Noakes PG. Dysregulation of the complement cascade in the hSOD1G93A transgenic mouse model of amyotrophic lateral sclerosis. J Neuroinflammation 2013; 10:119. [PMID: 24067070 PMCID: PMC3850877 DOI: 10.1186/1742-2094-10-119] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 09/06/2013] [Indexed: 12/13/2022] Open
Abstract
Background Components of the innate immune complement system have been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS); however, a comprehensive examination of complement expression in this disease has not been performed. This study therefore aimed to determine the expression of complement components (C1qB, C4, factor B, C3/C3b, C5 and CD88) and regulators (CD55 and CD59a) in the lumbar spinal cord of hSOD1G93A mice during defined disease stages. Methods hSOD1G93A and wild-type mice were examined at four different ages of disease progression. mRNA and protein expression of complement components and regulators were examined using quantitative PCR, western blotting and ELISA. Localisation of complement components within lumbar spinal cord was investigated using immunohistochemistry. Statistical differences between hSOD1G93A and wild-type mice were analysed using a two-tailed t-test at each stage of disease progression. Results We found several early complement factors increased as disease progressed, whilst complement regulators decreased; suggesting overall increased complement activation through the classical or alternative pathways in hSOD1G93A mice. CD88 was also increased during disease progression, with immunolocalisation demonstrating expression on motor neurons and increasing expression on microglia surrounding the regions of motor neuron death. Conclusions These results indicate that local complement activation and increased expression of CD88 may contribute to motor neuron death and ALS pathology in the hSOD1G93A mouse. Hence, reducing complement-induced inflammation could be an important therapeutic strategy to treat ALS.
Collapse
Affiliation(s)
- John D Lee
- School of Biomedical Sciences, University of Queensland, Brisbane, St Lucia QLD 4072, Australia.
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Fogarty MJ, Smallcombe KL, Yanagawa Y, Obata K, Bellingham MC, Noakes PG. Genetic deficiency of GABA differentially regulates respiratory and non-respiratory motor neuron development. PLoS One 2013; 8:e56257. [PMID: 23457538 PMCID: PMC3574162 DOI: 10.1371/journal.pone.0056257] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Accepted: 01/07/2013] [Indexed: 11/25/2022] Open
Abstract
Central nervous system GABAergic and glycinergic synaptic activity switches from postsynaptic excitation to inhibition during the stage when motor neuron numbers are being reduced, and when synaptic connections are being established onto and by motor neurons. In mice this occurs between embryonic (E) day 13 and birth (postnatal day 0). Our previous work on mice lacking glycinergic transmission suggested that altered motor neuron activity levels correspondingly regulated motor neuron survival and muscle innervation for all respiratory and non respiratory motor neuron pools, during this period of development [1]. To determine if GABAergic transmission plays a similar role, we quantified motor neuron number and the extent of muscle innervation in four distinct regions of the brain stem and spinal cord; hypoglossal, phrenic, brachial and lumbar motor pools, in mice lacking the enzyme GAD67. These mice display a 90% drop in CNS GABA levels ( [2]; this study). For respiratory-based motor neurons (hypoglossal and phrenic motor pools), we have observed significant drops in motor neuron number (17% decline for hypoglossal and 23% decline for phrenic) and muscle innervations (55% decrease). By contrast for non-respiratory motor neurons of the brachial lateral motor column, we have observed an increase in motor neuron number (43% increase) and muscle innervations (99% increase); however for more caudally located motor neurons within the lumbar lateral motor column, we observed no change in either neuron number or muscle innervation. These results show in mice lacking physiological levels of GABA, there are distinct regional changes in motor neuron number and muscle innervation, which appear to be linked to their physiological function and to their rostral-caudal position within the developing spinal cord. Our results also suggest that for more caudal (lumbar) regions of the spinal cord, the effect of GABA is less influential on motor neuron development compared to that of glycine.
Collapse
Affiliation(s)
- Matthew J Fogarty
- School of Biomedical Sciences, University of Queensland, Brisbane, Queensland, Australia
| | | | | | | | | | | |
Collapse
|
33
|
Narayanan RK, Mangelsdorf M, Panwar A, Butler TJ, Noakes PG, Wallace RH. Identification of RNA bound to the TDP-43 ribonucleoprotein complex in the adult mouse brain. Amyotroph Lateral Scler Frontotemporal Degener 2012; 14:252-60. [DOI: 10.3109/21678421.2012.734520] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
34
|
Ngo ST, Cole RN, Sunn N, Phillips WD, Noakes PG. Neuregulin-1 potentiates agrin-induced acetylcholine receptor clustering through muscle-specific kinase phosphorylation. J Cell Sci 2012; 125:1531-43. [PMID: 22328506 DOI: 10.1242/jcs.095109] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
At neuromuscular synapses, neural agrin (n-agrin) stabilizes embryonic postsynaptic acetylcholine receptor (AChR) clusters by signalling through the muscle-specific kinase (MuSK) complex. Live imaging of cultured myotubes showed that the formation and disassembly of primitive AChR clusters is a dynamic and reversible process favoured by n-agrin, and possibly other synaptic signals. Neuregulin-1 is a growth factor that can act through muscle ErbB receptor kinases to enhance synaptic gene transcription. Recent studies suggest that neuregulin-1-ErbB signalling can modulate n-agrin-induced AChR clustering independently of its effects on transcription. Here we report that neuregulin-1 increased the size of developing AChR clusters when injected into muscles of embryonic mice. We investigated this phenomenon using cultured myotubes, and found that in the ongoing presence of n-agrin, neuregulin-1 potentiates AChR clustering by increasing the tyrosine phosphorylation of MuSK. This potentiation could be blocked by inhibiting Shp2, a postsynaptic tyrosine phosphatase known to modulate the activity of MuSK. Our results provide new evidence that neuregulin-1 modulates the signaling activity of MuSK and hence might function as a second-order regulator of postsynaptic AChR clustering at the neuromuscular synapse. Thus two classic synaptic signalling systems (neuregulin-1 and n-agrin) converge upon MuSK to regulate postsynaptic differentiation.
Collapse
Affiliation(s)
- Shyuan T Ngo
- School of Biomedical Sciences, University of Queensland, St. Lucia, 4072, Queensland, Australia
| | | | | | | | | |
Collapse
|
35
|
Ghazanfari N, Fernandez KJ, Murata Y, Morsch M, Ngo ST, Reddel SW, Noakes PG, Phillips WD. Muscle specific kinase: organiser of synaptic membrane domains. Int J Biochem Cell Biol 2010; 43:295-8. [PMID: 20974278 DOI: 10.1016/j.biocel.2010.10.008] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Revised: 10/15/2010] [Accepted: 10/15/2010] [Indexed: 11/19/2022]
Abstract
Muscle Specific Kinase (MuSK) is a transmembrane tyrosine kinase vital for forming and maintaining the mammalian neuromuscular junction (NMJ: the synapse between motor nerve and skeletal muscle). MuSK expression switches on during skeletal muscle differentiation. MuSK then becomes restricted to the postsynaptic membrane of the NMJ, where it functions to cluster acetylcholine receptors (AChRs). The expression, activation and turnover of MuSK are each regulated by signals from the motor nerve terminal. MuSK forms the core of an emerging signalling complex that can be acutely activated by neural agrin (N-agrin), a heparin sulfate proteoglycan secreted from the nerve terminal. MuSK activation initiates complex intracellular signalling events that coordinate the local synthesis and assembly of synaptic proteins. The importance of MuSK as a synapse organiser is highlighted by cases of autoimmune myasthenia gravis in which MuSK autoantibodies can deplete MuSK from the postsynaptic membrane, leading to complete disassembly of the adult NMJ.
Collapse
Affiliation(s)
- Nazanin Ghazanfari
- Physiology and Bosch Institute, Anderson Stuart Bldg (F13), The University of Sydney, Sydney, NSW 2006, Australia.
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Azhar M, Wang PY, Frugier T, Koishi K, Deng C, Noakes PG, McLennan IS. Myocardial deletion of Smad4 using a novel α skeletal muscle actin Cre recombinase transgenic mouse causes misalignment of the cardiac outflow tract. Int J Biol Sci 2010; 6:546-55. [PMID: 20877696 PMCID: PMC2945925 DOI: 10.7150/ijbs.6.546] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Accepted: 09/08/2010] [Indexed: 12/17/2022] Open
Abstract
SMAD4 acts as the converging point for TGFβ and BMP signaling in heart development. Here, we investigated the role of SMAD4 in heart development using a novel α skeletal muscle actin Cre recombinase (MuCre) transgenic mouse strain. Lineage tracing using MuCre/ROSA26LacZ reporter mice indicated strong Cre-recombinase expression in developing and adult heart and skeletal muscles. In heart development, significant MuCre expression was noted at E11.5 in the atrial, ventricular, outflow tract and atrioventricular canal myocardium, but not in the endocardial cushions. MuCre-driven conditional deletion of Smad4 in mice caused double outlet right ventricle (DORV), ventricular septal defect (VSD), impaired trabeculation and thinning of ventricular myocardium, and mid-gestational embryonic lethality. In conclusion, MuCre mice effectively delete genes in both heart and skeletal muscles, thus enabling the discovery that myocardial Smad4 deletion causes misalignment of the outflow tract and DORV.
Collapse
Affiliation(s)
- Mohamad Azhar
- BIO5 Institute, and Department of Cell Biology and Anatomy, University of Arizona, Tucson, AZ 85724, USA.
| | | | | | | | | | | | | |
Collapse
|
37
|
Muttenthaler M, Nevin ST, Grishin AA, Ngo ST, Choy PT, Daly NL, Hu SH, Armishaw CJ, Wang CIA, Lewis RJ, Martin JL, Noakes PG, Craik DJ, Adams DJ, Alewood PF. Solving the alpha-conotoxin folding problem: efficient selenium-directed on-resin generation of more potent and stable nicotinic acetylcholine receptor antagonists. J Am Chem Soc 2010; 132:3514-22. [PMID: 20163143 DOI: 10.1021/ja910602h] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Alpha-conotoxins are tightly folded miniproteins that antagonize nicotinic acetylcholine receptors (nAChR) with high specificity for diverse subtypes. Here we report the use of selenocysteine in a supported phase method to direct native folding and produce alpha-conotoxins efficiently with improved biophysical properties. By replacing complementary cysteine pairs with selenocysteine pairs on an amphiphilic resin, we were able to chemically direct all five structural subclasses of alpha-conotoxins exclusively into their native folds. X-ray analysis at 1.4 A resolution of alpha-selenoconotoxin PnIA confirmed the isosteric character of the diselenide bond and the integrity of the alpha-conotoxin fold. The alpha-selenoconotoxins exhibited similar or improved potency at rat diaphragm muscle and alpha3beta4, alpha7, and alpha1beta1 deltagamma nAChRs expressed in Xenopus oocytes plus improved disulfide bond scrambling stability in plasma. Together, these results underpin the development of more stable and potent nicotinic antagonists suitable for new drug therapies, and highlight the application of selenocysteine technology more broadly to disulfide-bonded peptides and proteins.
Collapse
Affiliation(s)
- Markus Muttenthaler
- Institute for Molecular Bioscience, Division of Chemistry and Structural Biology, The University of Queensland, Brisbane, Queensland 4072, Australia
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Crane JW, Baiquni GP, Sullivan RK, Lee JD, Sah P, Taylor SM, Noakes PG, Woodruff TM. The C5a anaphylatoxin receptor CD88 is expressed in presynaptic terminals of hippocampal mossy fibres. J Neuroinflammation 2009; 6:34. [PMID: 19917081 PMCID: PMC2780381 DOI: 10.1186/1742-2094-6-34] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2009] [Accepted: 11/16/2009] [Indexed: 12/20/2022] Open
Abstract
Background In the periphery, C5a acts through the G-protein coupled receptor CD88 to enhance/maintain inflammatory responses. In the brain, CD88 can be expressed on astrocytes, microglia and neurons. Previous studies have shown that the hippocampal CA3 region displays CD88-immunolabelling, and CD88 mRNA is present within dentate gyrus granule cells. As granule cells send dense axonal projections (mossy fibres) to CA3 pyramidal neurons, CD88 expression could be expressed on mossy fibres. However, the cellular location of CD88 within the hippocampal CA3 region is unknown. Methods The expression of CD88 within the hippocampal CA3 region was characterized using dual-immunolabelling of hippocampal sections prepared from Wistar rats. Immunolabelling for CD88, using a monoclonal antibody, was combined with immunolabelling for markers of astrocytes (GFAP), microglia (IBA1), presynaptic proteins (synaptophysin and synapsin-1) and preterminal axons (neurofilament). In addition, electron microscopy was performed on peroxidase-visualized CD88-immunolabelling to determine its cellular localisation within the CA3 region. Results Dense CD88-immunolabelling was observed within the stratum lucidum of the CA3, consistent with the presence of CD88 on mossy fibres. Labelling for CD88 rarely co-localized with astrocytes or microglia, but was highly co-localized with presynaptic proteins. Electron microscopy revealed CD88-immunolabelling was localized to large presynaptic terminals within the stratum lucidum. Conclusion These results demonstrate that CD88 is expressed on presynaptic terminals of mossy fibres within the CA3 region of the hippocampus. Although the role of CD88 on mossy fibres remains to be established, their involvement in synaptic/cellular plasticity, and in cognitive disorders such as Alzheimer's disease deserves investigation.
Collapse
Affiliation(s)
- James W Crane
- Queensland Brain Institute, The University of Queensland, St, Lucia, Brisbane, Qld, 4072 Australia.
| | | | | | | | | | | | | | | |
Collapse
|
39
|
Barclay JL, Kerr LM, Arthur L, Rowland JE, Nelson CN, Ishikawa M, d'Aniello EM, White M, Noakes PG, Waters MJ. In vivo targeting of the growth hormone receptor (GHR) Box1 sequence demonstrates that the GHR does not signal exclusively through JAK2. Mol Endocrinol 2009; 24:204-17. [PMID: 19884384 DOI: 10.1210/me.2009-0233] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
GH is generally believed to signal exclusively through Janus tyrosine kinases (JAK), particularly JAK2, leading to activation of signal transducers and activators of transcription (STAT), ERK and phosphatidylinositol 3-kinase pathways, resulting in transcriptional regulation of target genes. Here we report the creation of targeted knock-in mice wherein the Box1 motif required for JAK2 activation by the GH receptor (GHR) has been disabled by four Pro/Ala mutations. These mice are unable to activate hepatic JAK2, STAT3, STAT5, or Akt in response to GH injection but can activate Src and ERK1/2. Their phenotype is identical to that of the GHR(-/-) mouse, emphasizing the key role of JAK2 in postnatal growth and the minimization of obesity in older males. In particular, they show dysregulation of the IGF-I/IGF-binding protein axis at transcript and protein levels and decreased bone length. Because no gross phenotypic differences were evident between GHR(-/-) and Box1 mutants, we undertook transcript profiling in liver from 4-month-old males. We compared their transcript profiles with our 391-GHR truncated mice, which activate JAK2, ERK1/2, and STAT3 in response to GH but not STAT5a/b. This has allowed us for the first time to identify in vivo Src/ERK-regulated transcripts, JAK2-regulated transcripts, and those regulated by the distal part of the GHR, particularly by STAT5.
Collapse
Affiliation(s)
- Johanna L Barclay
- Institute for Molecular Bioscience, University of Queensland, St. Lucia 4072, Australia.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Woodruff TM, Ager RR, Tenner AJ, Noakes PG, Taylor SM. The role of the complement system and the activation fragment C5a in the central nervous system. Neuromolecular Med 2009; 12:179-92. [PMID: 19763906 DOI: 10.1007/s12017-009-8085-y] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Accepted: 08/25/2009] [Indexed: 12/28/2022]
Abstract
The complement system is a pivotal component of the innate immune system which protects the host from infection and injury. Complement proteins can be induced in all cell types within the central nervous system (CNS), where the pathway seems to play similar roles in host defense. Complement activation produces the C5 cleavage fragment C5a, a potent inflammatory mediator, which recruits and activates immune cells. The primary cellular receptor for C5a, the C5a receptor (CD88), has been reported to be on all CNS cells, including neurons and glia, suggesting a functional role for C5a in the CNS. A second receptor for C5a, the C5a-like receptor 2 (C5L2), is also expressed on these cells; however, little is currently known about its potential role in the CNS. The potent immune and inflammatory actions of complement activation are necessary for host defense. However, if over-activated, or left unchecked it promotes tissue injury and contributes to brain disease pathology. Thus, complement activation, and subsequent C5a generation, is thought to play a significant role in the progression of CNS disease. Paradoxically, complement may also exert a neuroprotective role in these diseases by aiding in the elimination of aggregated and toxic proteins and debris which are a principal hallmark of many of these diseases. This review will discuss the expression and known roles for complement in the CNS, with a particular focus on the pro-inflammatory end-product, C5a. The possible overarching role for C5a in diseases of the CNS is reviewed, and the therapeutic potential of blocking C5a/CD88 interaction is evaluated.
Collapse
Affiliation(s)
- Trent M Woodruff
- School of Biomedical Sciences, University of Queensland, St. Lucia, Brisbane, 4072, Australia.
| | | | | | | | | |
Collapse
|
41
|
Woodruff TM, Costantini KJ, Crane JW, Atkin JD, Monk PN, Taylor SM, Noakes PG. The complement factor C5a contributes to pathology in a rat model of amyotrophic lateral sclerosis. J Immunol 2009; 181:8727-34. [PMID: 19050293 DOI: 10.4049/jimmunol.181.12.8727] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Complement activation products are elevated in the cerebrospinal fluid and spinal cord of patients with amyotrophic lateral sclerosis (ALS). In this study, we demonstrate complement system involvement in a rodent model of ALS (human SOD1(G93A) transgenic rats). With end-stage disease, SOD1(G93A) rats displayed marked deposition of C3/C3b, and a significant up-regulation of the C5aR in the lumbar spinal cord. This was associated with increased numbers of C5aR-positive astrocytes. However, expression of C5L2, the alternative receptor for C5a, was highest on motor neurons early in the disease process. To determine the contribution of C5a to the pathology displayed by this model of ALS, rats were administered an orally active, selective C5aR antagonist (PMX205; 1 mg/kg/day, oral). Animals treated with PMX205 displayed a significant extension of survival time and a reduction in end-stage motor scores, as compared with vehicle-treated rats. PMX205-treated animals also displayed reduced levels of astroglial proliferation in the lumbar spinal cord. This study provides the first demonstration of an involvement of C5a in an ALS model and suggests that inhibitors of complement activation could be beneficial in the treatment of this neurodegenerative disease.
Collapse
Affiliation(s)
- Trent M Woodruff
- School of Biomedical Sciences, University of Queensland, Brisbane, Australia
| | | | | | | | | | | | | |
Collapse
|
42
|
Brockhausen J, Cole RN, Gervásio OL, Ngo ST, Noakes PG, Phillips WD. Neural agrin increases postsynaptic ACh receptor packing by elevating rapsyn protein at the mouse neuromuscular synapse. Dev Neurobiol 2008; 68:1153-69. [PMID: 18506821 DOI: 10.1002/dneu.20654] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Fluorescence resonance energy transfer (FRET) experiments at neuromuscular junctions in the mouse tibialis anterior muscle show that postsynaptic acetylcholine receptors (AChRs) become more tightly packed during the first month of postnatal development. Here, we report that the packing of AChRs into postsynaptic aggregates was reduced in 4-week postnatal mice that had reduced amounts of the AChR-associated protein, rapsyn, in the postsynaptic membrane (rapsyn(+/-) mice). We hypothesize that nerve-derived agrin increases postsynaptic expression and targeting of rapsyn, which then drives the developmental increase in AChR packing. Neural agrin treatment elevated the expression of rapsyn in C2 myotubes by a mechanism that involved slowing of rapsyn protein degradation. Similarly, exposure of synapses in postnatal muscle to exogenous agrin increased rapsyn protein levels and elevated the intensity of anti-rapsyn immunofluorescence, relative to AChR, in the postsynaptic membrane. This increase in the rapsyn-to-AChR immunofluorescence ratio was associated with tighter postsynaptic AChR packing and slowed AChR turnover. Acute blockade of synaptic AChRs with alpha-bungarotoxin lowered the rapsyn-to-AChR immunofluorescence ratio, suggesting that AChR signaling also helps regulate the assembly of extra rapsyn in the postsynaptic membrane. The results suggest that at the postnatal neuromuscular synapse agrin signaling elevates the expression and targeting of rapsyn to the postsynaptic membrane, thereby packing more AChRs into stable, functionally-important AChR aggregates.
Collapse
Affiliation(s)
- Jennifer Brockhausen
- School of Medical Sciences (Physiology), Bosch Institute, University of Sydney, Sydney, Australia
| | | | | | | | | | | |
Collapse
|
43
|
Woodruff TM, Costantini KJ, Taylor SM, Noakes PG. Role of complement in motor neuron disease: animal models and therapeutic potential of complement inhibitors. Adv Exp Med Biol 2008; 632:143-158. [PMID: 19025120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is one of the major forms of motor neuron disease (MND), a group of degenerative disorders causing progressive motor neuron death leading to eventual paralysis and death. The pathogenesis of MND is poorly understood and may include genetic and/or environmental factors, with a common end-stage outcome. The majority of cases are sporadic, with a small percentage of familial cases identified. Mutations in the copper/zinc superoxide dismutase (SOD1) enzyme are frequent in familial ALS, and have allowed for the development of transgenic SOD1 rodent models of ALS. There has been evidence for immune system involvement in the disease, and activated components of the classical complement pathway have been observed in the serum, cerebrospinal fluid and neuronal tissue of diseased individuals. Furthermore, motor neurons and spinal cord tissue from SOD1 transgenic mice show an upregulation in C1q mRNA transcript and protein, in some cases prior to disease onset. Our laboratory has preliminary data indicating a specific pathogenic role for the activation fragment of complement C5 (C5a) in this disease. Using selective C5a receptor antagonists, we dosed SOD1 transgenic rats and observed an extension in survival and reduced motor symptoms compared to untreated rats. Collectively, these clinical and experimental findings suggest that targeting complement using specific inhibitors may represent a novel therapeutic approach to treating MND. Further experimental and clinical studies are required to validate this hypothesis. This review will summarize the clinical and experimental evidence to date implicating complement in the pathogenesis of MND.
Collapse
Affiliation(s)
- Trent M Woodruff
- School of Biomedical Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
| | | | | | | |
Collapse
|
44
|
Nguyen TT, Sheppard AM, Kaye PL, Noakes PG. IGF-I and insulin activate mitogen-activated protein kinase via the type 1 IGF receptor in mouse embryonic stem cells. Reproduction 2007; 134:41-9. [PMID: 17641087 DOI: 10.1530/rep-06-0087] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Although IGF-I and insulin are important modulators of preimplantation embryonic physiology, the signalling pathways activated during development remain to be elucidated. As a model of preimplantation embryos, pluripotent mouse embryonic stem cells were used to investigate which receptor mediated actions of physiological concentrations of IGF-I and insulin on growth measured by protein synthesis. Exposure of mouse embryonic stem (ES) cells to 1.7 pM IGF-I or 1.7 nM insulin for 4 h caused approximately 25% increase in protein synthesis when compared with cells cultured in basal medium containing BSA. Dose-response studies showed 100-fold higher potency of IGF-I that pointed to the type 1 IGF receptor as the mediating receptor for both ligands. This was confirmed using an anti-type 1 IGF receptor-blocking antibody (alphaIR3). Both 1.7 pM IGF-I and 1.7 nM insulin increased phosphorylation of the type 1 IGF receptor and this increase was blocked by alphaIR3, but the insulin receptor was not phosphorylated. Finally, binding of either agonist led to downstream phosphorylation of ERK1/2 mitogen-activated protein kinase (MAPK) also via IGF-1R as this was blocked by alphaIR3. Together, these results suggest that IGF-I and insulin modulate ES cell physiology through binding to the type 1 IGF receptor and subsequent activation of MAPK pathway.
Collapse
Affiliation(s)
- Thanh T Nguyen
- School of Biomedical of Sciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | | | | | | |
Collapse
|
45
|
Barclay M, Noakes PG, Ryan AF, Julien JP, Housley GD. Neuronal expression of peripherin, a type III intermediate filament protein, in the mouse hindbrain. Histochem Cell Biol 2007; 128:541-50. [PMID: 17899157 DOI: 10.1007/s00418-007-0340-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/23/2007] [Indexed: 11/28/2022]
Abstract
Peripherin is a 57 kDa Type III intermediate filament protein associated with neurite extension, neuropathies such as amyotrophic lateral sclerosis, and cranial nerve and dorsal root projections. However, knowledge of peripherin expression in the CNS is limited. We have used immunoperoxidase histochemistry to characterise peripherin expression in the mouse hindbrain, including the inferior colliculus, pons, medulla and cerebellum. Peripherin immunolabelling was observed in the nerve fibres and nuclei that are associated with all cranial nerves [(CN) V-XII] in the hindbrain. Peripherin expression was prominent in the cell bodies and axons of the mesenchephalic trigeminal nucleus and the pars compacta region of nucleus ambiguus, and in the fibres that comprise the solitary tract, the descending spinal trigeminal tract and the trigeminal and facial nerves. A small proportion of peripherin positive fibres in CN VIII likely arise from cochlear type II spiral ganglion neurons. Peripherin positive fibres were also observed in the inferior cerebellar peduncle and folia in the intermediate zone of the cerebellum. Antibody specificity was confirmed by absence of labelling in hindbrain tissue from peripherin knockout mice. This study shows that in the adult mouse hindbrain, peripherin is expressed in discrete neuronal subpopulations that have sensory, motor and autonomic functions.
Collapse
Affiliation(s)
- Meagan Barclay
- Department of Physiology, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | | | | | | | | |
Collapse
|
46
|
Chen F, Qian L, Yang ZH, Huang Y, Ngo ST, Ruan NJ, Wang J, Schneider C, Noakes PG, Ding YQ, Mei L, Luo ZG. Rapsyn interaction with calpain stabilizes AChR clusters at the neuromuscular junction. Neuron 2007; 55:247-60. [PMID: 17640526 DOI: 10.1016/j.neuron.2007.06.031] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2006] [Revised: 03/27/2007] [Accepted: 06/25/2007] [Indexed: 12/28/2022]
Abstract
Agrin induces, whereas acetylcholine (ACh) disperses, ACh receptor (AChR) clusters during neuromuscular synaptogenesis. Such counteractive interaction leads to eventual dispersal of nonsynaptic AChR-rich sites and formation of receptor clusters at the postjunctional membrane. However, the underlying mechanisms are not well understood. Here we show that calpain, a calcium-dependent protease, is activated by the cholinergic stimulation and is required for induced dispersion of AChR clusters. Interestingly, the AChR-associated protein rapsyn interacted with calpain in an agrin-dependent manner, and this interaction inhibited the protease activity of calpain. Disrupting the endogenous rapsyn/calpain interaction enhanced CCh-induced dispersion of AChR clusters. Moreover, the loss of AChR clusters in agrin mutant mice was partially rescued by the inhibition of calpain via overexpressing calpastatin, an endogenous calpain inhibitor, or injecting calpeptin, a cell-permeable calpain inhibitor. These results demonstrate that calpain participates in ACh-induced dispersion of AChR clusters, and rapsyn stabilizes AChR clusters by suppressing calpain activity.
Collapse
Affiliation(s)
- Fei Chen
- Institute of Neuroscience and Key Laboratory of Neurobiology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
O'Leary DA, Noakes PG, Lavidis NA, Kola I, Hertzog PJ, Ristevski S. Targeting of the ETS factor GABPalpha disrupts neuromuscular junction synaptic function. Mol Cell Biol 2007; 27:3470-80. [PMID: 17325042 PMCID: PMC1899955 DOI: 10.1128/mcb.00659-06] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The GA-binding protein (GABP) transcription factor has been shown in vitro to regulate the expression of the neuromuscular proteins utrophin, acetylcholine esterase, and acetylcholine receptor subunits delta and epsilon through the N-box promoter motif (5'-CCGGAA-3'), but its in vivo function remains unknown. A single point mutation within the N-box of the gene encoding the acetylcholine receptor epsilon subunit has been identified in several patients suffering from postsynaptic congenital myasthenic syndrome, implicating the GA-binding protein in neuromuscular function and disease. Since conventional gene targeting results in an embryonic-lethal phenotype, we used conditional targeting to investigate the role of GABPalpha in neuromuscular junction and skeletal muscle development. The diaphragm and soleus muscles from mutant mice display alterations in morphology and distribution of acetylcholine receptor clusters at the neuromuscular junction and neurotransmission properties consistent with reduced receptor function. Furthermore, we confirmed decreased expression of the acetylcholine receptor epsilon subunit and increased expression of the gamma subunit in skeletal muscle tissues. Therefore, the GABP transcription factor aids in the structural formation and function of neuromuscular junctions by regulating the expression of postsynaptic genes.
Collapse
Affiliation(s)
- Debra A O'Leary
- Monash Institute of Medical Research, Monash University, Clayton, Victoria 3168, Australia
| | | | | | | | | | | |
Collapse
|
48
|
Abstract
Neural agrin is a heparan sulphate proteoglycan first defined by its ability to induce the clustering of acetylcholine receptors (AChRs) on cultured muscle cells. Neural agrin activates the transmembrane Muscle Specific Kinase (MuSK) on the postsynaptic muscle cell to stabilise the developing neuromuscular synapse. Three biological mechanisms for agrin/MuSK signalling are briefly discussed: selective transcription of synaptic genes such as MuSK itself, to reinforce developing postsynaptic clusters of AChRs; initiation of second messenger signalling pathways that can induce the formation of AChR clusters and retrograde signalling downstream of agrin/MuSK that may transform the growth cone of the motor axon into a stable differentiated nerve terminal, specialised for regulated exocytosis of neurotransmitter. Here we briefly review some key mechanisms through which neural agrin acts to foster the formation of mature neuromuscular synapses.
Collapse
Affiliation(s)
- Shyuan T Ngo
- Synaptic Biology Group, School of Biomedical Sciences (Physiology), University of Queensland, St. Lucia, Queensland, Australia
| | | | | |
Collapse
|
49
|
Rowland JE, Kerr LM, White M, Noakes PG, Waters MJ. Heterozygote effects in mice with partial truncations in the growth hormone receptor cytoplasmic domain: assessment of growth parameters and phenotype. Endocrinology 2005; 146:5278-86. [PMID: 16166215 DOI: 10.1210/en.2005-0939] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The GH receptor (GHR) is essential for normal postnatal growth and development, and the molecular basis of GHR action has been studied intensively. Clinical case studies and more recently mouse models have revealed the extensive phenotype of impaired GH action. We recently reported two new mouse models, possessing cytoplasmic truncations at position 569 (plus Y539/545-F) and 391, which were created to identify functional subdomains within the cytoplasmic signaling domain. In the homozygous state, these animals show progressively impaired postnatal growth coupled with complex changes in gene expression. We describe here an extended phenotype analysis encompassing the heterozygote state to identify whether single copies of these mutant receptors bring about partial or dominant-negative phenotypes. It appears that the retention of the ubiquitin-dependent endocytosis motif in the N-terminal cytoplasmic domain permits turnover of these mutant receptors because no dominant-negative phenotype is seen. Nonetheless, we do observe partial impairment of postnatal growth in heterozygotes supporting limited haploinsufficiency. Reproductive function is impaired in these models in a progressive manner, in parallel with loss of signal transducer and activator of transcription-5 activation ability. In summary, we describe a more comprehensive phenotypic analysis of these mouse models, encompassing overall and longitudinal body growth, reproductive function, and hormonal status in both the heterozygote and homozygote state. Our results suggest that patients expressing single copies of similarly mutated GHRs would not display an obvious clinical phenotype.
Collapse
Affiliation(s)
- Jennifer E Rowland
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, Australia
| | | | | | | | | |
Collapse
|
50
|
Banks GB, Kanjhan R, Wiese S, Kneussel M, Wong LM, O'Sullivan G, Sendtner M, Bellingham MC, Betz H, Noakes PG. Glycinergic and GABAergic synaptic activity differentially regulate motoneuron survival and skeletal muscle innervation. J Neurosci 2005; 25:1249-59. [PMID: 15689563 PMCID: PMC6725962 DOI: 10.1523/jneurosci.1786-04.2005] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
GABAergic and glycinergic synaptic transmission is proposed to promote the maturation and refinement of the developing CNS. Here we provide morphological and functional evidence that glycinergic and GABAergic synapses control motoneuron development in a region-specific manner during programmed cell death. In gephyrin-deficient mice that lack all postsynaptic glycine receptor and some GABA(A) receptor clusters, there was increased spontaneous respiratory motor activity, reduced respiratory motoneuron survival, and decreased innervation of the diaphragm. In contrast, limb-innervating motoneurons showed decreased spontaneous activity, increased survival, and increased innervation of their target muscles. Both GABA and glycine increased limb-innervating motoneuron activity and decreased respiratory motoneuron activity in wild-type mice, but only glycine responses were abolished in gephyrin-deficient mice. Our results provide genetic evidence that the development of glycinergic and GABAergic synaptic inputs onto motoneurons plays an important role in the survival, axonal branching, and spontaneous activity of motoneurons in developing mammalian embryos.
Collapse
Affiliation(s)
- Glen B Banks
- School of Biomedical Sciences, University of Queensland, St. Lucia, 4072 Queensland, Australia
| | | | | | | | | | | | | | | | | | | |
Collapse
|