Quick Project Snapshot

Targeting exosome-mediated propagation of protein misfolding in MND

MND is characterised by anatomically focal onset of symptoms which radiate in a contiguous pattern, consistent with propagation of underlying motor neuron loss and pathology.  The factor(s) that mediate neuroanatomical spread of MND remain debated, but these are likely to be diffusible, present in extracellular fluids and therefore targetable.  We recently discovered that intercellular propagation of protein misfolding is mediated by "exosomes" in MND models.  Exosomes are small secretory vesicles released by cells and capable of transmitting RNA and protein to recipient cells.  This project seeks to modulate exosome secretion in human primary motor neuron culture systems and transgenic mouse models of MND.  The effects of genetic and chemical approaches to modulate exosome release will be evaluated on clinical progression, neuropathology and distribution of misfolded proteins in the central nervous system of mouse models of MND.

Electron micrograph of exosomes secreted by motor neuronal cells and stained for misfolded SOD1 protein

Key paper

Grad LI,* Yerbury JJ,* Turner BJ*, Guest WC, Pokrishevsky E, O'Neill MA, Yanai A, Silverman JM, Zeineddine R, Corcoran L, Kumita JR, Luheshi LM, Yousefi M, Coleman BM, Hill AF, Plotkin SS, Mackenzie IR, Cashman NR (2014) Intercellular propagated misfolding of wild-type Cu/Zn superoxide dismutase occurs via exosome-dependent and -independent mechanisms. Proc Natl Acad Sci USA 111:3620-3625. *equal first author.

http://www.ncbi.nlm.nih.gov/pubmed/24550511

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HEAD OF LAB
Dr Bradley Turner

Motor Neurone Disease Laboratory

Neurodegenerative diseases have a devastating impact on quality of life and impose a tremendous burden on the health care system.  Among neurodegenerative conditions, motor neurodegenerative diseases are the among the most rapidly fatal, with increasing disability and death within 2-3 years from symptom onset.  Our laboratory is primarily focused on understanding the molecular basis of motor neuron disease (MND), also called amyotrophic lateral sclerosis (ALS). We are also interested in other motor neurodegenerative disorders, including spinal muscular atrophy (SMA) and spinal bulbar muscular atrophy (SBMA), more commonly known as Kennedy's disease.

Our team employs a combination of cell and molecular biology to unravel MND pathogenesis in patient-derived samples, cell culture and animal models.  We seek to identify and understand the primary mechanisms underlying motor neuron vulnerability, stress and injury in MND, while translating our discoveries into relevant biomarkers and targets for effective intervention. Our group is particularly interested in the molecular determinants of protein misfolding and accumulation within neurons, and harnessing endogenous cellular protective mechanisms to combat protein misfolding.  We also investigate mechanisms of misfolded protein propagation in the central nervous system in MND with the goal to arrest disease spread.  

A further area of investigation is the therapeutic action of survival motor neuron (SMN) protein for SMA and MND.  We have discovered that SMN restoration slows disease progression and improves motor neuron survival in mouse models of MND, in addition to SMA mouse models. This has led to development of motor neuron targeted SMN gene therapy approaches for both SMA and MND.

   Motor neurons stained for Hb9 (red) Tuj-1 (green)

Collaborations

International:

Prof Dame Kay Davies and Prof Kevin Talbot, University of Oxford

Dr Severine Boillee, Brain and Spine Institute, Paris

Prof Neil Cashman, University of British Columbia

Prof Uri Saragovi, McGill University

 

National:

Prof Steve Vucic, University of Sydney

Dr Mary-Louise Rogers and Dr Hakan Muyderman, Flinders University

Dr Justin Yerbury, University of Wollongong

Prof Julie Atkin, Macquarie University

Assoc Prof Danny Hatters, University of Melbourne

Prof Philip Beart and Prof Malcolm Horne, University of Melbourne

 

Funding

Australian National Health and Medical Research Council

Bethlehem Griffiths Research Foundation

Cure for MND Foundation

Motor Neuron Disease Research Institute of Australia

Nick Baldi Construction Pty Ltd

Pratt Foundation

SciOpen Research Group

Stafford Fox Medical Research Foundation

Vowell Foundation

All Projects by this Lab

Stimulating autophagy to improve intracellular proteostasis in MNDTargeting exosome-mediated propagation of protein misfolding in MNDDeveloping SMN gene therapy for SMA and MNDGenerating novel mouse models of Kennedy's disease
CO-HEAD OF DIVISION

Professor Philip Beart

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CO-HEAD OF DIVISION

Prof Colin Masters

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Biophysics Laboratory

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HEAD OF LAB
Dr Simon Drew

Oxidation Biology Unit

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Prof Ashley Bush

Prana Laboratory

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Dr Robert Cherny

Neurodegeneration

Scientists in the Neurodegeneration division interrogate how neurones live, die and can be rescued to improve brain function in degenerative conditions such as Parkinson’s and Motor Neuron Diseases. There is no effective treatment for Motor Neurone Disease and the incidence of Parkinson’s Disease is rising alarmingly in our aging community. Gene abnormalities, energy deprivation, toxic rubbish accumulation and inflammation all contribute to a toxic environment for brain cells. Our teams study these events in animal models and cultured cells, with a view to translating knowledge into new therapies for human patients.

All Labs that operate in this Division

Atomic Pathology LaboratoryBiophysics LaboratoryCellular Neurodegeneration LaboratoryCreutzfeldt Jakob Disease Clinical Research GroupMolecular Gerontology LaboratoryMotor Neurone Disease LaboratoryNational Dementia Diagnostics LaboratoryNeurochemistry of Metal IonsNeurogenesis and Neural Transplantation LaboratoryNeuropathology and Neurodegeneration LaboratoryNeuroproteomics and Metalloproteomics LaboratoryNeurotherapeutics LaboratoryOxidation Biology UnitParkinson's Disease LaboratoryPrana LaboratoryPre-clinical Parkinson’s Disease Research LaboratoryPresynaptic Physiology Stem Cells and Neural Development LaboratorySteroid Neurobiology LaboratorySynaptic Neurobiology LaboratoryThe Australian Imaging Biomarker and Lifestyle Study (AIBL)