Abeta-mediated toxicity in Alzheimer's disease: delineating mechanisms of internalisation, cell-cell transmission and synaptic dysfunction

Lead Research Organisation: University of Sussex
Department Name: Sch of Life Sciences

Abstract

Alzheimer's disease (AD) is a devastating illness that affects 1% of the population. Although some familial forms of AD exist, most Alzheimer's patients suffer from sporadic, late-onset AD, associated with ageing. The causes of Alzheimer's disease remain unclear, although it is now well-established that in brain cells (neurons), abnormal folding of small proteins (called Abeta and tau) represents a pivotal step in disease pathology. Our work aims to understand how these proteins can lead to the deterioration of neuronal function underlying the degenerative symptoms seen in Alzheimer's sufferers. To examine this we will use both artificially-grown and native networks of living neurons and recapitulate the changes occurring at the onset of AD as the target proteins change and become toxic. We will utilise state-of-the-art imaging methods to directly visualise the effects on basic neuronal function. Our research will also examine how the spread of toxic proteins between neurons might underlie the progression of the disease. A specific consequence of AD is the gradual dysfunction of synapses - the sites for neuron-to-neuron signalling - that are essential for the brain's ability to process information. We will use specialised fluorescence markers to examine synaptic signalling events and characterise the specific mechanisms which become disrupted. Finally, we will combine our fluorescence measurements with novel state-of-the-art microscopy experiments, allowing us to examine the detailed structural changes in neurons caused by misfolding proteins at high-resolution. Using this approach, we anticipate major new insights into understanding the critical cellular and molecular changes associated with Alzheimer's disease. With this knowledge, the rational design of therapeutic agents that can target these processes and alleviate or prevent disease symptoms becomes a realistic prospect.

Technical Summary

Alzheimer's disease is characterised by the abnormal association of Abeta (Ab) peptide to form oligomeric species, with catastrophic consequences for neuronal function and survival. However, clear understanding of the mechanisms by which Ab exerts toxicity remains elusive. Specifically, it is not known how Ab is transmitted around neural networks, how it internalises/accumulates in neurons, the nature of its cellular/molecular targets, or the mechanisms which underlie its disruption of critical neuronal synaptic processes. This proposal will exploit established and novel biochemical, imaging and ultrastructural approaches in cultured and native hippocampal neurons to examine these issues, providing fundamental new insights into the toxic mechanisms of Ab action.

A key aim is to translate our recent findings from neuroblastoma cells, defining a pathway of Ab internalisation, into primary neurons. Ab will be tracked alongside cellular/organelle markers to examine endocytic processes and targeting to specific compartments, and followed by ultrastructural investigation. Ab transmission around neuronal networks will be assayed with genetically-encoded fusion constructs providing insight into the spreading of Ab pathology in Alzheimer's patients. We will also examine Ab consequences on presynaptic function - specifically dynamic properties of vesicle pools. Our pilot data indicates striking Ab-induced effects on functional pool partitioning, lateral vesicle trafficking and vesicle endocytic efficiency. Alongside culture experiments we will use an established transgenic model to explore synapse-specific presynaptic deficits in acute slice. This approach also permits a function-ultrastructure readout of recycling vesicles in native tissue, offering unique insights into Ab-induced vesicle pool re-organisation. Our findings will shed new light on pivotal steps in the pathway of Ab action, providing important potential targets for the rational development of therapeutics.

Planned Impact

This proposal aims to understand the molecular mechanisms underlying the toxicity of Abeta in Alzheimer's disease. The prevalence of Alzheimer's is growing as the ageing population increases. Therapies are available, but these slow disease progress rather than halting it. The need for more fundamental research into underlying mechanisms is highlighted by the recent withdrawal from further development of a promising therapeutic agent, Bapineuzumab. Therapeutic design is hampered by a lack of clear insight into the disease process. In this work, we aim to provide a better understanding of the underlying disease mechanisms and our long term goal is to identify key targets for rational drug design that will lead to an improvement both for society and for the individual patient.

1. Who will benefit from this research?
This research will provide a clearer understanding of the key processes involved in Alzheimer's disease. This will impact in two major ways: First, it will provide the scientific basis for potential targets for drug development; Second, it will provide a clearer knowledge regarding early changes associated with disease development and therefore contribute to the possibility of early diagnosis. If Alzheimer's disease is to be combated, it is essential that any therapeutic is provided prior to irreversible neuronal cell death. This research will provide information for pharmaceutical companies developing therapeutics agents for Alzheimer's disease and in the longer term this will impact on the health service and wider public. In the past few years, clear statements have been made regarding the priority for research into neurodegenerative diseases from the UK Government and the EU, as well as the USA. This research project is likely to inform policy makers in terms of specific investment in research into the most important targets for Alzheimer's disease.

2. How will they benefit?
In the long term, this research will contribute to the enhancement of public health by adding to understanding aimed at improving treatment for Alzheimer's disease. This research will be disseminated in peer-review journals, at international meetings and also communicated to the public via Café Scientifique and the media. The research group has links with Pharma via collaboration with the translational drug discovery group recently established at the University of Sussex. Pharmaceutical companies will benefit from the clearer understanding of the disease process and potential targets on which to base design and development of drugs for Alzheimer's disease. Clinicians working with Alzheimer's patients will have a foundation for researching early diagnosis, since our findings will report on initial changes that occur in response to elevated toxic Abeta. The broader public will gain longer term benefits from improvements in treatments for Alzheimer's disease and this in turn will impact on the economy and wealth and health of the nation. The research may be used to produce therapeutics that slow or halt the disease progression, providing enhanced quality of life for those suffering from Alzheimer's disease and those caring for patients. This is a three year grant from which we would aim to provide the basis for targets for the development of therapeutics. The realistic expectation for the impact is that in the next 10 years, drugs may be developed based on our results.

Professional development
The work will deliver and train highly-skilled researchers, with expertise in organization, analysis, communication and scientific writing, relevant to many employment sectors. The PDRA will undertake a broad range of techniques including novel state-of-the art function-ultrastructure approaches developed in the Staras lab - skills of benefit to the wider academic and industrial communities. Both laboratories regularly provide projects for MSc and undergraduate internships and in this way training will be disseminated to the broader community.
 
Description A central role for dityrosine cross-linking in Alzheimer's and other neurodegenerative diseases
Amount £357,000 (GBP)
Organisation Alzheimer’s Society 
Sector Charity/Non Profit
Country United Kingdom
Start 11/2017 
End 10/2020
 
Description ARUK equipment Grant
Amount £76,825 (GBP)
Organisation Alzheimer's Research UK 
Sector Charity/Non Profit
Country United Kingdom
Start 05/2018 
End 06/2018
 
Description Alzheimer's society, doctoral training centre
Amount £450,000 (GBP)
Organisation Alzheimer’s Society 
Sector Charity/Non Profit
Country United Kingdom
Start 10/2014 
End 10/2018
 
Description Higher Education Innovation Fund - University of Sussex
Amount £10,000 (GBP)
Organisation University of Sussex 
Sector Academic/University
Country United Kingdom
Start 05/2018 
End 07/2018
 
Description MRC Discovery Award
Amount £117,040 (GBP)
Organisation Medical Research Council (MRC) 
Sector Academic/University
Country United Kingdom
Start 06/2016 
End 06/2018
 
Description MRC Programme Grant
Amount £2,056,454 (GBP)
Organisation Medical Research Council (MRC) 
Sector Academic/University
Country United Kingdom
Start 04/2017 
End 03/2022
 
Description Multi-User Equipment Award
Amount £337,311 (GBP)
Funding ID WT208348/Z/17/Z 
Organisation Wellcome Trust 
Sector Charity/Non Profit
Country United Kingdom
Start 11/2017 
End 11/2022
 
Description TAURX/Wista funding for postdoc
Amount £600,000 (GBP)
Organisation TauRx Pharmaceuticals Ltd. 
Sector Private
Country Singapore
Start 02/2014 
End 02/2019
 
Title Developed a control peptide for Abeta 
Description We have developed a non-assembling, non-toxic variant of Amyloid Beta for use in Alzheimer's studies 
Type Of Material Technology assay or reagent 
Year Produced 2015 
Provided To Others? Yes  
Impact This has the potential to transform the field of Abeta research, as it provides a carefully controlled method to enable the effects of Abeta to be studied 
 
Title Development of CypHer tag to monitor internalisation of Abeta into neuronal cells. 
Description We have developed methods to tag Abeta oligomers to allow us to monitor internalisation concurrent with a pH probe. This development will be reported in a manuscript in preparation. 
Type Of Material Technology assay or reagent 
Year Produced 2019 
Provided To Others? No  
Impact This is a valuable tool to allow us to monitor pH alongside internalisation and can be used to others. 
 
Description Collaboration on APPSwe/Ind dox tg mice 
Organisation University of Southampton
Country United Kingdom 
Sector Academic/University 
PI Contribution Collaboration to use APPswe/Ind Dox animals to better understand the role of Abeta in Synaptic damage
Collaborator Contribution The animals are bred in Southampton and are provided by them for the experiments at Sussex
Impact Experiments have been completed and analysis is currently being conducted and the results are being prepared for publication
Start Year 2016
 
Description Collaboration with Janssen Pharmaceuticals 
Organisation Janssen Research & Development
Country Global 
Sector Private 
PI Contribution BBSRC CASE studentship looking at pharmacology of synaptic vesicle recycling with Janssen as Industrial Partner. PhD student is currently on industrial placement in Belgium.
Collaborator Contribution Writing of successful award of CASE studentship. Dialogue during reciprocal visits to Belgium and Sussex between teams.
Impact Preliminary evidence on effects of Levetiracetam on vesicle recycling.
Start Year 2014
 
Description Diamond 
Organisation Diamond Light Source
Country United Kingdom 
Sector Academic/University 
PI Contribution We have prepared neuronal cells on grids to be imaged using Cryo Soft Xray microscopy At BL24. We have collected preliminary data and these are being analysed
Collaborator Contribution The collaborators at BL24 have provided equipment and training.
Impact Currently the data is being analysed
Start Year 2014
 
Description ARUK network public dementia day 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? Yes
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact We presented our work in a manner that was suitable for the broad audience and this sparked interesting discussions

This raised awareness of research into dementia in the regional area (south)
Year(s) Of Engagement Activity 2013,2014
 
Description ARUK public information day, 2016 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact The Serpell group presented a small public engagement workshop about their work on Dementia at the Southampton based ARUK South network symposium.
Year(s) Of Engagement Activity 2016
 
Description Alzheimer's society DTC public event and scientific meeting (ApoE) 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact A scientific meeting was organised as part of the University of Sussex Alzheimer's society DTC and this was contributed to by members of the laboratory including Karen Marshall who is employed as a postdoc on this grant.
Year(s) Of Engagement Activity 2016
 
Description Alzheimer's society DTC public event and scientific meeting (ApoE) 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Louise Serpell and Karen Marshall were interviewed for ITV meridian news as part of the event.
Year(s) Of Engagement Activity 2016
 
Description Applicant visitors day 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact Specialized visitor day for sixth form students and guests with firm interest in neuroscience study. Covered degree structure but also wider implications of neuroscience and some discussion of research.
Year(s) Of Engagement Activity 2017
 
Description Bright Sparks: Brighton science festival 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Other audiences
Results and Impact Louise Serpell and members of the research group spent the day at the BrightSparks event in Brighton which is part of the Brighton science festival, demonstrating our research and related activities to children and their parents.
Year(s) Of Engagement Activity 2017
 
Description Epsom mental health day 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Talk to members of the Public at Epsom mental health week.
Year(s) Of Engagement Activity 2015,2016
 
Description Invited Research Seminar (King's College London) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Professional Practitioners
Results and Impact Invited seminar at King's College London to ~100 or more research scientists, PG and UG students.
Year(s) Of Engagement Activity 2016
 
Description Invited Research Talk at German Neuroscience Meeting, Gottingen 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Invited to speak at major research conference; there was significant interest in my seminar. I made key new contacts in the research field topic. Through this meeting, I have also set up a collaboration with the cryo-EM group at the Max Planck Institute in Gottingen.
Year(s) Of Engagement Activity 2017
 
Description Life and a Career in Science 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Postgraduate students
Results and Impact International women day. Organised a symposium called Life and a Career in Science displaying different pathways that are followed by scientists.
Year(s) Of Engagement Activity 2017
URL http://www.sussex.ac.uk/Lifesci/AthenaSwan
 
Description Micromachines to Cellular Networks, Invited Symposium Speaker, Sussex, UK 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact A locally organized two-day meeting to publicize our growing expertise in cryo-EM methods. My talk sparked key questions/discussion. A key outcome was that I spoke with likely reviewers for a cryo-EM Wellcome Trust equipment bid which I applied for, and was subsequently awarded.
Year(s) Of Engagement Activity 2017
 
Description Neuroscience talk (Sussex) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact A seminar on research to neuroscience community at Sussex
Year(s) Of Engagement Activity 2015
 
Description Open day visit 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact Large-scale talk to 100+ people on broad ideas about neuroscience as a career direction. Included potential students and members of public.
Year(s) Of Engagement Activity 2015
 
Description Open lab for non-scientists 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact An open lab session, showing non-scientists from the university some examples of research approaches/principles being used in our work. It included a short talk and opportunity to engage with ongoing experiments, talk to researchers etc. Very well-received.
Year(s) Of Engagement Activity 2015
 
Description Open lab session for visiting sixth form students and general public 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Schools
Results and Impact Set up lab for sixth form and general public to view neuronal cultures and electron microscopy data. Lots of interest and questions.
Year(s) Of Engagement Activity 2017
 
Description Participation in ARUK public information day, 2017 (Feb 1) 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Workshops organised by Alzheimer's research UK network to engage public in Alzheimer's research. These are held once or twice a year and members of the public, patients and carers are invited to talk to researchers in a series of science "cafes".
Year(s) Of Engagement Activity 2015,2016,2017
 
Description Participation in Bright Sparks as part of Brighton Science festival 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact 100s of local people and their children attended a large event to engage people in science.
Year(s) Of Engagement Activity 2018
 
Description Participation in an open day or visit at my research institution - Open lab session for visiting sixth form students and general public 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact Open lab demonstration. Showing neurons and multimedia which explains fundamental research.
Year(s) Of Engagement Activity 2018
 
Description Potential undergraduate student and parent visit to university 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact Talk covering background to neuroscience, studying neuroscience, research etc. to broad audience interested in a possible future in this discipline.
Year(s) Of Engagement Activity 2015
 
Description Public engagement event at BEIS 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact My research group and members of the Alzheimer's society DTC visited the BEIS to discuss research into Alzheimer's disease with staff. We presented activities and explained our research
Year(s) Of Engagement Activity 2017
 
Description Research Talk at Open Day 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Schools
Results and Impact Neuroscience talk/open afternoon for non-scientists with an interest in future undergraduate studies. Talk included neuroscience research and information on specific of neuroscience degrees at Sussex. Good interests and questions on careers in neuroscience.
Year(s) Of Engagement Activity 2017
 
Description STEM ambassador activity at St. Catherine's Catholic School for Girls 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact During her time in the lab, my postdoc, Stephanie Rey has carried out training to be a STEM (science, teaching, engineering and maths) ambassador. This activity was a talk to pupils (~13 y.o.) at St. Catherine's Catholic School for Girls, Bexley, London, UK on neuroscience, studying and a scientific career.
Year(s) Of Engagement Activity 2017
 
Description Soap box science 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Soap box science at Brighton Seafront to talk to the public about our research. Women in Science
Year(s) Of Engagement Activity 2017
URL http://soapboxscience.org/soapbox-science-2017-brighton/
 
Description Speaker at teachers conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact A talk on my research topic - under 'Hot Topics' session - primarily my current BBSRC and MRC work - communicated to teacher's in science disciplines. The aim is to motivate and excite teachers and their teaching by giving them insight into the latest-breaking approaches in research. Feedback from session was outstanding.
Year(s) Of Engagement Activity 2015
 
Description Talk to U3A 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Talk to the University of the Third Age based in Sutton, Surrey. Science branch. Over 60 attendees.
Year(s) Of Engagement Activity 2016