The mechanism and regulation of axonal transport of tau

Lead Research Organisation: King's College London
Department Name: Unlisted

Abstract

Alzheimer?s disease is the most common neurodegenerative disease, affecting over half a million elderly people in the UK and representing around 1% of the population. The present demographic change is set to continue and so there will be a rising proportion of affected people. Although there are now some effective treatments, these are all symptomatic and do not halt or slow the relentless loss of nerve cells in the brain, such that after a while the treatments fail and patients continue to deteriorate and die. In the case of Alzheimer?s disease, the nerve cells that die are those required for higher functions of the brain, including memory and cognition, whereas cells important for movement are relatively spared. Hence Alzheimer patients are perfectly able to walk, at least until the more advanced stages, but early on in the disease have memory difficulties. There are two characteristic abnormalities in the brain in Alzheimer?s disease: these are the presence of senile plaques and neurofibrillary tangles. The senile plaques have a central deposit of a protein known as amyloid and new drugs aimed at preventing amyloid production are being developed. Less is known about the neurofibrillary tangles, which are made of another protein called tau. However, it has been discovered recently that mutations in the gene for tau give rise to some other neurodegenerative diseases related to Alzheimer?s disease but that these other conditions have no amyloid deposits. This has led to the realisation that tau or neurofibrillary tangles are also important in Alzheimer?s disease and their presence inside nerve cells may well directly result in death of those cells. This project is aimed at understanding how tau becomes abnormal and forms the neurofibrillary tangles since it will then be possible to devise strategies to prevent tangle formation and hopefully prevent death of the nerve cells, which may be a much more effective treatment than we presently have available because it would tackle the underlying disease process. The successful outcome of the project will therefore help validate drug discovery programmes that are directed at enzymes known as protein kinases that modify tau and hence believed to be potentially useful targets; the project it may also lead to the discovery of new drug targets for treating Alzheimer?s disease.

Technical Summary

Intraneuronal inclusions in Alzheimer?s disease and related tauopathies are composed of aggregated and hyperphosphorylated tau. Tau inclusions are generally believed to lead directly to neuronal cell dysfunction and death. So far, the mechanism by which the normal form of tau is transformed into filamentous aggregates and kills cells has eluded researchers. One hypothesis is that defective axonal transport resulting from hyperphosphorylation of tau is an important neurodegenerative mechanism, giving rise to a local increase in concentrations of tau, followed by its aggregation and disruption of transport of other organelles. We propose to address this hypothesis by investigating the mechanism and regulation of axonal transport of tau and determining if mutations and pathological phosphorylation of tau adversely affect its transport and that of other organelles. Our objectives are to model in transgenic mice the effects of introducing (knock-in) a known miss-sense mutation in tau and knock-in mimics of hyperphosphorylated tau on axonal transport of tau and organelles and the behavioural and pathological consequences of these mutant forms of tau. We shall treat cultured neurons expressing EGFP-tagged tau with pharmacological agents or siRNA to modulate protein phosphorylation in order to determine which protein kinases and phosphatases regulate physiological tau phosphorylation and which of these influence transport of tau and organelles in cultured neurons, as assessed by real-time video, differential interference and confocal microscopy. We shall use a quantitative mass spectrometry approach to identify phosphorylation sites for different protein kinases and phosphatases. We shall make additional tau phosphomimic transgenic mice and use the same neuronal culture system to model the effects of interfering with critical phosphorylation sites involved in the regulation of axonal transport of tau and organelles and determine the influence of phosphorylation at these sites on in vitro microtubule dynamics. We shall prepare monoclonal antibodies to any novel phosphorylation sites in tau to investigate the status of such sites in normal and pathological brain tissue. We shall use pull-down techniques to characterise the complement of proteins in the tau transport complex, including determining if this complex is affected by known disease-causing mutations in tau or by phosphorylation. We shall use pull-down techniques and mass spectrometry to determine the molecular mechanisms underlying tau axonal transport by identifying the molecular motors involved and how phosphorylation changes modulate tau transport. The outcome will be clearer picture of the role of phosphorylation in tau pathology and possibly the identification of novel drug targets.

Publications

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Adalbert R (2007) Abeta, tau and ApoE4 in Alzheimer's disease: the axonal connection. in Trends in molecular medicine

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Babetto E (2010) Targeting NMNAT1 to axons and synapses transforms its neuroprotective potency in vivo. in The Journal of neuroscience : the official journal of the Society for Neuroscience

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Beirowski B (2009) Non-nuclear Wld(S) determines its neuroprotective efficacy for axons and synapses in vivo. in The Journal of neuroscience : the official journal of the Society for Neuroscience

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Cuchillo-Ibanez I (2008) Phosphorylation of tau regulates its axonal transport by controlling its binding to kinesin. in FASEB journal : official publication of the Federation of American Societies for Experimental Biology

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Hanger DP (2010) Tau cleavage and tau aggregation in neurodegenerative disease. in Biochemical Society transactions

 
Description ART PhD Studentship
Amount £88,720 (GBP)
Funding ID ART-PhD2008-4 
Organisation Alzheimer's Research UK 
Sector Charity/Non Profit
Country United Kingdom
Start 01/2008 
End 01/2011
 
Description ART project grant
Amount £284,092 (GBP)
Funding ID ART-PG2009-2 
Organisation Alzheimer's Research UK 
Sector Charity/Non Profit
Country United Kingdom
Start  
 
Description ARUK PhD Scholarship
Amount £93,227 (GBP)
Funding ID ART-PhD2011-15 
Organisation Alzheimer's Research UK 
Sector Charity/Non Profit
Country United Kingdom
Start  
 
Description ARUK Travelling Research Fellowship
Amount £220,297 (GBP)
Funding ID ART-TRF2011-2 
Organisation Alzheimer's Research UK 
Sector Charity/Non Profit
Country United Kingdom
Start 09/2011 
End 08/2014
 
Description BI project grant/Babraham Institute
Amount £96,000 (GBP)
Organisation Biotechnology and Biological Sciences Research Council (BBSRC) 
Sector Public
Country United Kingdom
Start  
 
Description CHDI project
Amount £63,000 (GBP)
Organisation CHDI Foundation 
Sector Charity/Non Profit
Country United States
Start  
 
Description HSC project grant
Amount £210,000 (GBP)
Organisation The Henry Smith Charity 
Sector Charity/Non Profit
Country United Kingdom
Start 01/2008 
End 01/2011
 
Description MRC project grant
Amount £896,584 (GBP)
Organisation Medical Research Council (MRC) 
Sector Public
Country United Kingdom
Start  
 
Title Axonal transport measurement 
Description ImageJ plugins for fully automated analysis of multiple axonal transport parameters 
Type Of Material Model of mechanisms or symptoms - in vitro 
Year Produced 2012 
Provided To Others? Yes  
Impact Access to new method through publically available ImageJ software. Use in publication 
 
Title P301L tau transgenic mice 
Description Tau P301L knockin transgenic mice 
Type Of Material Model of mechanisms or symptoms - mammalian in vivo 
Provided To Others? No  
Impact Manuscript on P301L mice accepted for publication Material used to provide preliminary data for grant applications. 
 
Title Phosphorylation-deficient transgenic mice 
Description Tau phosphorylation-deficient transgenic mice 
Type Of Material Model of mechanisms or symptoms - mammalian in vivo 
Provided To Others? No  
Impact These animals are currently being characterised 
 
Title Phosphorylation-mimic transgenic mice 
Description Tau phosphorylation-mimic transgenic mice 
Type Of Material Model of mechanisms or symptoms - mammalian in vivo 
Provided To Others? No  
Impact These animals are currently being characterised 
 
Title Tau mutant cDNA constructs 
Description Phospho-mimic and phospho-defective tau mutant cDNA constructs 
Type Of Material Model of mechanisms or symptoms - in vitro 
Year Produced 2006 
Provided To Others? Yes  
Impact Used to generate transgenic mice. Also used in cellular systems to mimic effects of disease. Used in publications. 
 
Description FP6 network NeuronE 
Organisation European Commission
Department EC FP6 Collaborative Projects
Country European Union (EU) 
Sector Academic/University 
PI Contribution Invited member of FP6 network NeuronE (MC)
Collaborator Contribution Enhanced EU networking (MC)
Impact Presentations at annual meetings, including results with P301L tau mouse
Start Year 2006
 
Description Proteome Sciences 
Organisation Proteome Sciences plc
Country United Kingdom 
Sector Private 
PI Contribution Generation of material for mass spectrometric analysis
Collaborator Contribution Mass spectrometry of phosphorylated proteins
Impact PMID: 17562708
 
Title Nmnat2 modulator 
Description N/A 
IP Reference GB0902147.8 
Protection Patent application published
Year Protection Granted 2009
Licensed No
Impact Publications, as listed PATENT APPLICATION TERMINATED 2010
 
Title Tau phosphorylation sites 
Description Tau phosphorylation sites identified on material extracted from human brain. Methods for screening for substances capable of modulating the phosphorylation of tau protein are disclosed, and in particular paired helical filament (PHF) tau, and the use of such modulators in the treatment of tauopathies. The assays and screening methods are based on the identification of new phosphorylation sites in PHF tau and new kinases and combinations of kinases as therapeutic targets, in particular the identification of casein kinase 1 as a kinase which phosphorylates tau protein. 
IP Reference WO2005001114 
Protection Patent granted
Year Protection Granted
Licensed No
Impact PMID: 17562708
 
Company Name Proteome Sciences plc 
Description http://www.proteomics.com/ 
Impact Joint patents with King's College London relating to tau phosphorylation in Alzheimer's disease. Development of TMT methodology for quantitative proteomics. Biomarker assays
Website http://www.proteomics.com/products-and-services/cns/alzheimers-plasma-9-plex
 
Description ARUK Open Day 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Type Of Presentation Workshop Facilitator
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact 120 members of the public attended an Open Day at the Institute of Psychiatry, Psychology & Neuroscience, King's College London

This event is always over-subscribed and has positive feedback from attendees
Year(s) Of Engagement Activity 2013,2014,2015,2016
 
Description Cambridge Science Festival 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? Yes
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Cambridge Science Festival demonstration from Babraham Institute (MC)

Cambridge Science Festival
Year(s) Of Engagement Activity 2008
 
Description Lay talk 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Lay talk at an ART fundraising lunch (MC)

Raising awareness
Year(s) Of Engagement Activity 2006
 
Description Open Day 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Public Open Day on dementia and neurodegeneration, including talks and lab tours
Year(s) Of Engagement Activity Pre-2006,2006,2007,2008,2009,2010,2011,2012,2013,2014,2015,2016,2017
 
Description Open Day 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Demonstrations at MRC Centre for Neurodegeneration Research Open Day

Not known
Year(s) Of Engagement Activity 2006,2007,2008
 
Description Open Day 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Presentations to members of the public at the MRC Centre for Neurodegeneration Open Day, King's College London

Presentation of information
Year(s) Of Engagement Activity 2006,2007,2008,2010,2011
 
Description PSP Bulletin 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? Yes
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Regular contributions describing progress to the Progressive Supranuclear Palsy Association Bulletin

Not known
Year(s) Of Engagement Activity 2006,2007,2008
 
Description Report 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? Yes
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Article provided on work in my reseearch group which was published in the Institute of Psychiatry Annual Research Report

Not known
Year(s) Of Engagement Activity 2008
 
Description School visit to Babraham Institute 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Group discussions of research data and hands-on practical experience to school children

Interest in science
Year(s) Of Engagement Activity 2006,2007,2008,2009,2010
 
Description Wikipedia 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Edited pages on axon degeneration in Wikipedia (MC)

Edited pages on axon degeneration in Wikipedia
Year(s) Of Engagement Activity 2009
 
Description Year 12 mock interviews 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Year 12 school students underwent formal mock interviews

School reports that this is very useful for students preparing for university and for taking up employment after leaving school
Year(s) Of Engagement Activity 2011,2012,2013,2014,2015,2016