Illuminating Alzheimer s shining a light on York s search for a cure

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My name is Kyla Holt and I'm Head of Volunteering  and Alumni Programmes at the University of York.   It's my great pleasure to welcome you to this  event on Illuminating Alzheimer's Disease   this evening. Hosting our event is Mr. Peter  Burley, one of our longest-serving and most   dedicated volunteers for the University of  York. Peter, can I invite you to take over? Hi. Thank you very much, Kyla,  yes, I'm Peter Burley and I chair   the London Alumni committee and the London Alumni  branch is the largest globally of many branches.  

I graduated from York in History in 1970  and I have to say that my continuing   relationship with the university has  been a source of great satisfaction. Our speaker this evening is Dr. Stephen Quinn and  he studied at St Andrews and Oxford University   starting in 2004. His academic career progressed  and his current appointment is in the Department   of Biophysics at York in 2017 in the Biological  Nanosystems group, we're beginning to get to the   edge of my comprehension here! He works at  the interface between physics and biology   and any attempt by me to describe his research in  more detail it's wavy on my pay grade so I'm just   hoping he can speak for himself there. What I can  say is the list of research papers and conferences  

attributed to him is impressive. I have a personal  interest in this topic because my mother-in-law   died of Alzheimer's and my wife, Jenny, worked  for the Alzheimer's society for several years.   I noticed that uh Dr. Quinn's most career most  recent career entry his work was presented to the   Alzheimer's Research UK's conference in March this  year. Alzheimer's Research UK is the UK's leading   charity dedicated to researching the causes,  diagnosis, treatment, and cure for Alzheimer's   and it was set up in 1992 to address the lack of  any campaigning body for this sort of academic and   medical research and it has since been behind some  of the biggest breakthroughs in dementia research. Well, that's enough of me it gives me great  pleasure now to hand over Stephen Quinn to   speak to us on illuminating Alzheimer's shining  light on developments in research. Thank you.

Thank you so much, Peter, so I'll just share my  screen with everyone and hopefully, you can see   this as well as my fancy new laser pointer that  I managed to get my hands on earlier this week.   So, as Peter said, I am part of the biological  nanosystems group at the University of York,   which is part of the wider Physics of Life network  and I'm here today to tell you that the field   of single-molecule biophysics is genuinely  at the forefront of modern science because   it's allowing the very building blocks of human  life so DNA and RNA and proteins to be viewed   and imaged and analyzed, but perhaps more  importantly, and maybe even most importantly   for the first time, single-molecule bioimaging  is allowing us to understand the very building   blocks of human disease and in this talk, I  want to showcase how we use single-molecule   bioimaging approaches to unveil the molecular  basis of Alzheimer's disease and of course today   is World Alzheimer's day and so  it's perfectly timed for this talk So, what is Alzheimer's Disease? Well, we often  say that dementia is the umbrella term for   symptoms such as loss of memory symptoms such  as the loss of your ability to critically and   think and interpret and of all of the dementias  alzheimer's is the most abundant constituting   around 60 to 80 percent of cases there are  of course other forms of dementia including   Parkinson's Disease, Huntington's Frontotemporal  Dementia, Vascular Dementia, Lewy Body Dementia   and mixed combinations of dementia but as I  say the key point here is that Alzheimer's   Disease is by far the most common and the most  abundant and in terms of clinical symptoms   related to alzheimers disease specifically we're  talking about memory loss confusion frustration   disorientation changes to your cognition  and ultimately personality changes   now alzheimer's research uk estimate that  right now there are around 850 000 people   in the uk living with dementia and of course that  really means that there's over half a million   people right now in the uk living with alzheimer's  disease globally the the number of people living   with dementia is is immense um we expect that  number to increase um by around 204 percent by   2050 and of course that is uh is a huge economic  burden for for society because along with   the patients of course suffering there are huge  economic costs associated with uh with health   care so alzheimer's disease really is a major  global concern for both patients and families   and carers alike and i do encourage you to check  out the alzheimer's research uk statistics hub   where you can really get more of a flavor for the  true impact of alzheimer's disease but basically   in alzheimer's disease brain matter disappears  over the course of time so on the top here   you see a healthy brain and in the bottom panel  you see a diseased brain and the clear difference   between the two brains is a clear loss of material  so brain cells die over time and that again leads   to death of the patient ultimately if we look at  the mortality rates associated with for example   stroke shown in the green curve here heart disease  shown in the blue curve and lung cancer shown in   the yellow curve you can see that certainly  the mortality rates associated with stroke   and heart heart disease generally are decreasing  over over time same with stroke lung cancer   has remains relatively steady but notice the  red curve here this is the one associated with   dementia and of course alzheimer's disease  which is progressively increasing and again   the the number of people living with alzheimer's  disease is expected to increase that means that   the economic costs associated with alzheimer's  disease will inevitably increase and right now   without an effective treatment unfortunately  these death rates will continue to increase so   alzheimer's disease is a major major problem that  we scientists must address in terms of the the   biochemical signatures we think that the the first  biochemical signatures of alzheimer's disease   appear around 15 years before the first symptoms  arise and there's two signatures so-called senile   plaques which are made up of beta-amyloid proteins  and neurofibrillary tangles which are made up   of tau proteins so these are the two major  hallmarks inside an alzheimer's disease brain   the beta amyloid plaques are made from the  beta-amyloid protein and that in turn is   formed by the cleavage for the snippet if you  like of a much larger protein called the amyloid   precursor protein so the amyloid precursor protein  interacts with basically little pairs of scissors   and we get release of the beta amyloid fragment  and this fragment is a protein it can fold and   twist and bend into a variety of different  shapes but it can also misfold and when it   misfolds it can cluster together to form these  senile plaques and again the senile plaques   are a characteristic hallmark of an advanced  alzheimer's brain in other words if you take   an advanced alzheimer's brain or a brain slice  you will observe an abundance of senile plaques   composed of the beta-amyloid protein so these  biochemical signatures we think begin to appear   long long before the clinical symptoms first  arise and one of the major unmet challenges   facing alzheimer's disease is to identify people  in this early disease phase when the beta-amyloid   clusters are beginning to form so that not only  we can better understand alzheimer's disease   but we can intervene before the disease  progresses clinically in other words before   the clinical symptoms begin to arise so if i  just recap here we have a single healthy cell   the neurofibrillary tangles composed of the  tyre protein in an advanced alzheimer patient   are generally found inside the cells the amyloid  plaques on the other hand are located outside   the cells and both we think are extremely toxic  in the context of this talk i'm going to focus   on the amyloid clusters and again the amyloid  clusters or the amyloid plaques are formed through   the accumulation of this beta-amyloid protein and  notice its shape here it's an l-like shape with   what we call an alpha helical conformation  notice this helix shape within the l-shape   so the beta-amyloid protein again is formed  through the cleavage the snippet if you like   of the amyloid precursor protein so the amyloid  precursor protein interacts with two pairs of   scissors called beta and gamma secretes and this  is the green fragment the beta-amyloid protein   that's ultimately released these proteins can  then accumulate into again these large amyloid   plaques and here's an electron microscopy image  of a plaque that we grew inside the laboratory   you can see that it's um several hundreds of  nanometers in size and you can also see that's   very heterogeneous in other words there are areas  that are less dense than others there are areas   that contain more proteins than others so this  is just a really big nasty mix of of proteins   with no real defined shape or structure so  accumulation of beta-amyloid is a major hallmark   of alzheimer's disease and therefore understanding  plaque growth and plaque formation is absolutely   critical to better understand and therefore  treat the disease so this begs the question   well if we have the amyloid precursor protein and  we get release of this toxic beta-amyloid fragment   um can't we just stop it from forming in the  first place and so this this question if you   like leads to a series of other questions and  one of those included does the amyloid actually   have a normal biological function in other words  beta amyloid is implicated in alzheimer's disease   why do we have this protein in our brains in  the in the first place so a lot of research   went into this particular question because as i  said um if it was perhaps hypothesized that if   we blocked the formation of the beta-amyloid  protein we could block disease pathogenesis   but the results from this particular  question i think we're quite fascinating   um a number of papers suggested first of  all that the beta amyloid protein could bind   to other proteins so it appeared to have  some kind of function and in particular   it could bind to proteins in the mitochondria of  cells and this is the area of the cells associated   with energy production so there's some links  beginning to appear between the beta-amyloid   protein and energy production and we also know it  can cross the the blood brain barrier so in other   words beta amyloid seems also to be implicated  in the transport of proteins throughout the body   but perhaps the most interesting of  all the papers published in the last   10 or so years was this one published by robert  moyer's lab and as the title of the paper suggests   the amyloid beta protein is now suspected to  be an antimicrobial peptide or an antimicrobial   protein in other words we suspect the beta-amyloid  protein though constitutes alzheimer's disease is   also part of the immune system and what he found  was really quite startling it had very similar   properties to the general antimicrobial proteins  found in our immune system it was active against   seven common types of bacteria including e coli  and importantly it had a striking resemblance   in terms of its properties and in many cases  outperformed the most abundant antimicrobial   protein in our body ll-37 so taking all of  this evidence together there's really good   um suggestions that the beta amyloid protein  actually is essential for our normal biological   function but of course it's clearly implicated  in alzheimer's disease so amyloid is part of the   immune system so what are the key open questions  as i've mentioned we get plaque formation through   the accumulation of the beta-amyloid protein but  what we don't yet understand are what specific   cells are involved during this toxic protein  cluster formation and when do they become involved   and specifically what are the first  of all the cells to be involved   and what follows when a cell perhaps  interacts with a beta-amyloid protein cluster   and and why and as a consequence we don't fully  understand how the brain circuits actually fail   and underpinning all of this we still really don't  understand fully what nanoscopic mechanisms are   involved and this is where mylab comes in we  are specifically interested in understanding   the very building blocks of the protein clustering  process and importantly how these individual and   very distinct protein clusters um cause toxicity  and one of the hypotheses that we're working   towards is that the amyloid protein clusters  effectively punch holes within the cells and that   can lead we think to the leakage of vital cellular  contents that leads to the cell ultimately dying   we also don't know whether or not these  processes begin at birth so i've said   that these biochemical signatures appear to begin  around 15 years before the first clinical symptoms   arise but really we don't know what triggers this  protein clustering in the in the first place and   the ultimate goal the ultimate open question is  can we achieve sensitive early stage diagnostics   and effective treatments and both of these  questions are questions which we and my colleagues   are also working on in york we're trying to  develop rapid and sensitive and multiplex   blood testing technologies to try and identify  people in the earliest possible stages such that   we can more effectively and more efficiently  search for the next generation of therapeutics   so with that being said um my colleagues  in in york um span biology and chemistry   physics and the social sciences trying to  understand alzheimer's disease across multiple   length and time scales from the very earliest  building blocks of beta-amyloid protein assembly   which can take place over several nanoseconds  that's a thousandth of a millionth of a second   right the way through to entire populations of  people and how these populations interact so my   colleagues in in social policy are interested in  uh population studies my colleagues in biology are   interested in understanding the global dynamics  of the organs involved in alzheimer's disease of   course the brain being a key player and we're  also interested in the behaviors of cells and   different types of cells in response to stress and  in particular in response to these toxic protein   clusters and the physics department are largely  involved with the generation of tools typically   optical tools for studying protein structure and  why are we interested to study protein structure   what protein structure is related ultimately  to protein function and in my lab which is   is based largely in the the science part we are  interested in understanding the building blocks   of alzheimer's disease on the nano scale and  very recently we've installed a new piece of   instrumentation funded by the epsrc the  engineering and physical sciences research council   to understand alzheimer's disease on a time  scale of picoseconds so that's a thousandth of   a nanosecond and a nanosecond is a thousandth of  a millionth of a second so we're really trying to   interrogate um alzheimer's disease  at the very very earliest stages   so if i go back to the beta  amyloids protein these proteins   are produced and they ultimately form these  large plaques which we find inside the the brain   but in order to get to the plaque-like stage they  have to cluster together first of all into small   clusters that we term oligomers and these  oligomers as they progressively get longer   and larger leads to the formation of long  stringy-like objects that we call fibrils   and these fibrils as they fold and twist and bend  and really manifest themselves around each other   lead ultimately to the formation of the  plaques and whilst early research in fact   the earliest research into alzheimer's disease  focused specifically on the fibrils and plaques   recent evidence now implicates the small  oligomers the earliest assemblies if you   like as being orders of magnitude more harmful  in other words we believe that the damage is done   in an alzheimer's brain at the very early  stages of protein assembly and so a number   of questions have arisen as a consequence and  the main question is how do these oligomers form   and importantly which oligomer if any is the most  toxic and ultimately how can we stop them from   growing so as i've mentioned a number of tools  and techniques have been developed largely by the   the physicists to understand the the structure  and ultimately the function of specifically the   fibrils and plaques so electron microscopy and the  number of biological stains have been developed   for that purpose and in our lab we're using single  molecule bioimaging technologies to really address   open questions in this part of the aggregation  spectrum so what is single molecule bioimaging   well you can think of single molecule bioimaging  as an extension to normal microscopy so we know   when we look down the barrel of a microscope we  can very easily distinguish between for example   uh live or or immobilized organisms um human hairs  biological cells even bacteria in other words   we can identify objects that are typically  millimeters in size down to objects that are   typically a few micrometers in in size a  micrometer is a thousandth of a millimeter   but we cannot using conventional microscopy  identify clusters of viruses we cannot   differentiate um multiple viruses in the cluster  we certainly can't differentiate using optical   microscopy and certain proteins in a cluster  they're simply too small and we certainly   cannot image single molecules and that's because  of this term up here abbey's diffraction limit   optical microscopes are really really good at  allowing you to identify and distinguish between   single clusters when those clusters are relatively  far apart so greater than 200 nanometers um   in in terms of their spatial position but they're  really not so good at differentiating between   objects and on the nano scale and this is where  single molecule bio imaging comes in because the   trick here is to attach a small fluorescent dye  molecule to your protein of interest in this case   that allows optical microscopy to visualize the  the protein clusters or the viral clusters or   the clusters of molecules now in the context of  our work we attach highlight floor 555 shown in   the red star to our beta amyloid proteins so this  is a little fluorescent dye molecule that absorbs   strongly in the green parts of the electromagnetic  spectrum in other words it absorbs green light   very well and it strongly emits red light and  that red light we can capture using our optical   microscopy techniques to obtain images such as the  one shown on the right hand side so essentially   i take my fluorescently tagged beta amyloid  proteins i allow them to cluster together i can   change the environmental conditions i can switch  for example the salt concentration in a solution   i can change the acidity of the solution i can  change things like concentration i've got very   good control over the environmental conditions  of the beta amyloid protein in the test tube   and when i've formed clusters i can deposit  those clusters onto a glass microscope slide   that sits on top of a microscope i can then inject  laser lights from this box into the microscope   slides that then stimulates the fluorescence  emission the emission of the red light from my my   sample and i can collect this on a camera that we  cool to about minus 80 degrees celsius and again   we're left with images such as the one shown in  the right hand side clearly defined spots that   exist against a dark background and what you're  observing here are single clusters of the beta   amyloid protein and the the blue dark background  is the the microscope slide so we can now using   single molecule bioimaging in combination with  the attachment of a fluorescent dye molecule   clearly resolve objects that are much smaller  than the abbey diffraction limit 200 nanometers   so how are we um doing this and a little bit  more of the physicsy detail well we're using   a technique called total internal  reflection fluorescence microscopy   and this is allowing us to visualize um not just  single protein clusters and single proteins but   hundreds of those single proteins and hundreds  of those single oligomers in parallel and in real   time so what we do is we take our laser beam and  rather than simply injecting it into the sample   we deliberately shine it off of the glass  microscope slide such that it reflects rather than   refracts into the sample and we do this because  maxwell famous physicist tells us that at the   point of total internal reflection when this beam  becomes reflected we generate a secondary beam   of light that penetrates into the sample and that  secondary beam of light penetrates only around 200   nanometers into the sample which basically means  that we only get light emission from molecules   from fluorescent molecules which are sufficiently  close enough i.e attached to the microscope slide   that allows me to minimize any background noise  and obtain what we call in physics a good signal   to noise ratio so i can minimize my background  counts and i can maximize my signal counts   the fluorescence is generated and we collect  it from below using an optical lens and we   pass that fluorescence on to our cooled uh  camera and again we get an image that looks   something like this where each spot corresponds  to a single um a ligament so not only can we   um collect images we can collect timestamps we can  monitor these spots in in real time we can monitor   how they might evolve over time and importantly we  can extract the intensity of a single cluster and   monitor the intensity over over time so what  you see on the right hand side here is a 3d   representation of the image on the the left where  each peak corresponds to the presence of a single   protein cluster and just notice some qualitatively  that some of the the spots are brighter than   others and that's indicative of some of the  clusters essentially being larger than others   now the way to interpret these microscopy images  is much in the same way that you might interpret a   satellite image so here we have a satellite image  collected from the nasa earth observatory of the   united states and what you can clearly see  is a series of bright spots or bright regions   against a dark background and of course we  know where austin is we know where atlanta   is we know where new york city is and you  can see that these areas are the brightest   of the bunch now in austin in atlanta in new  york city we of course have a number of people   we have a number of apartment blocks a number of  street lamps a huge number of office buildings   and what i'm getting at here is that the  brightness of the city or the brightness of   the town is a good indicator of the population  so if you look closely um near chicago you can   see again various little towns appearing and in  the background you can also see much less bright   spots corresponding to villages so brightness  is really an excellent indicator of population   the more office blocks we have the more apartment  blocks we have with the lights switched on the   more street lamps we have is a good indicator of  the number of people residing in those those areas   so let's imagine we have a city in the united  states of america and let's imagine we ask   everyone to turn their lights on inside their  office blocks inside their apartment block at   the same time and now let's imagine i look at  that brightness of the spot over over time and   assuming all of the light bulbs are functioning  correctly and everyone keeps their lights on when   i ask them to then over time the brightness of the  city will remain relatively constant or unchanged   but then if i ask people to randomly switch  off their their lights so to progressively   run around their office blocks or um their  houses and turn off the light bulbs one by one   then as they do this the brightness of the city  will become progressively dimmer and dimmer and as   each light bulb is turned off the city brightness  will ultimately decrease in a stepwise manner   until such a point for all the lights in the  city have been turned off and the city brightness   turns to zero so using this trick of monitoring  the brightness of a spot in this example i can   estimate to a very good degree of accuracy the  number of light bulbs for the number of lamps   that might exist within a particular city so the  number of turning off events that i observe is an   excellent indicator of the number of light bulbs  present in the area of of interest and this is the   the trick that we use to investigate the building  blocks of alzheimer's disease because we take   our fluorescent images of the pre-formed protein  clusters or of the single proteins that exist   on the microscope slide and we monitor their  intensity over time and in much the same way   as your light bulbs in your house or your office  have a lifetime in some cases several years   several months the fluorescent dye molecules  also have a lifetime and they can turn off   quite rapidly after a few seconds especially when  a high power of green light is instant upon them   so in other words we can deliberately ask these  fluorescent dye molecules to turn off one by one   and so what you see in the middle here is a 3d  representation of fluorescent protein clusters   this is in real time and you can monitor that  these peaks gradually disappear if i zoom into   a single peat peak perhaps you can see that the  turning off occurs in a stepwise like manner   so in other words if i have for example a protein  cluster that contains four individual proteins and   each protein has a fluorescent tag attached to it  then if i monitor the brightness as a function of   time under my conditions of high excitation power  or high green light power i will monitor a number   of turning off events and the number of turning  off events are so so-called photo bleaching   steps that i observe will directly correspond to  the number of single proteins within my cluster   so in the example i've got here i see four turning  off events and that tells me i've got four single   dye molecules inside the cluster of interest  and that corresponds to four single proteins   so the key point from this slide and the take-home  message is that the number of photobleaching steps   corresponds to the number of single proteins or  monomers as we call them inside a single oligomer   and so using this trick of stepwise photobleaching  we can identify single proteins so this would be   a single protein with a single dye  attached to it in other words we observe   one step we can identify the earliest stage of  protein self-assembly in other words a dimer   a protein cluster with two single proteins  in it and this is a a trace that would show   two steps we can identify those with three  and four and five steps such as the one shown   on the bottom left hand side so a protein cluster  containing five single proteins should display   five turning off events and a hexamer a protein  cluster with six uh single proteins in it   um should display six photo bleaching steps  like the the graph shown on the bottom right   now why do we want to do this well we think that a  a dimer has very different levels of toxicity to a   pentamer and a pentamer has very different levels  of toxicity to a hexamer so by interrogating our   overall sample and understanding which types of  species we have we can more effectively understand   which are the most toxic and therefore perhaps  the most relevant for inhibitors so we can get   unique access to monomer to a ligament aggregation  using this technique we can even go as far as to   identifying protein clusters that contain around  32 photobleaching steps we think in the literature   at the moment the record is around 10 but as i  say we think we can beat that by a factor of 3   and identify 30 30 tumors essentially the more  and more fluorescent dye molecules you have and   the more noisy your data becomes and it becomes  even more difficult to quantify particularly   large structures so single molecule bioimaging  is really great for understanding the earliest   stages of protein self-assembly but less so for  understanding the the larger crusted clusters   and brightness is also a really good indicator  as i've mentioned so the the overall initial   brightness will scale with the number of single  um proteins within the the cluster so we can also   use brightness as an indicator and in this  particular sample we can see the majority of   species based on the brightness were monomers so  these were species that contained a single step   there was some levels of dimers around 30 so those  species displaying two photobleaching steps and we   even had a few trimers and those which displayed  three photobleaching steps so photobleaching plus   brightness um are two optical signatures or  optical fingerprints of alzheimer's disease on   the nanoscale it's become a bit of a tradition now  that when we collect data like this for the first   time that we stop everything that we're doing and  we immediately grab the cameras and take a photo   so this is myself and dr alex payne dwyer who  spent an enormous amount of time building the   the microscope and collecting the single molecule  stepwise photobleaching data for the for the first   time now why is this important well we can access  heterogeneity within a sample we can identify how   many monomers that are relative to dimers and how  many dimers there are relative to trimmers for for   example so here's the example of an aggregation  system where at time zero minutes the majority of   species displayed one protein or one peptide pair  a ligament but there was some evidence of dimers   with a few timers and under the environmental  conditions that we used you can see the evolution   of this histogram over time so in other words  we see an increase in the number of dimers   and trimers and dimers and tetramers even after  15 minutes and that progresses even further   at time one hour so now the number of monomers in  the system has vastly reduced and the the system   the solution is swamped with oligomers but  importantly after one hour and in the presence   of an inhibitor you can see that this histogram  is very very similar to that obtained at time   zero so this is now telling us that we can  block the aggregation using putative inhibitors   so single molecule bioimaging technology is  not only giving us a new understanding of what   particular species might exist within a sample  but it's also leading towards more effective and   efficient drug screening as we can monitor what  happens in the presence of a potential aggregate   blocker so just to summarize we have a situation  in alzheimer's disease where these single proteins   progress into fibros and plaques via oligomers  a number of microscopy based techniques and a   number of biological stains have been developed  to identify the fibrils and plaques but where   there's a real gap in our knowledge regarding  how the monomers progress into oligomers we're   using single molecule bioimaging techniques which  is essentially utilizing fluorescently labeled   beta-amyloid proteins as a means to provide  unique insights into a ligamer information   and for those of you who are interested  in this work we have now published   this paper in the journal methods um this is an  open access paper so it's free to to view and it's   titled amyloid beta oligomerization monitored  by single molecule and stepwise photobleaching   and our hope is that the biologists the physicists  and the chemists of this uh this world will take   our tools and techniques and more effectively  and efficiently screen for the next generation   of inhibitors and this work would not be  possible without the combination of chemistry and   physics and biology and therefore the combination  of chemists physicists and biologists and we're   really blessed at york that we have a really  great team of interdisciplinary scientists working   on this uh this project so i have to thank alex  payne dwyer for building the the microscope um   lara dresser was heavily involved in collecting  much of the data that you observed today   along with patrick hunter jamie howards did a lot  of work on the protein purification side of things   and jion lee who is now working in edinburgh did  a lot of work on figuring out how to immobilize   the proteins onto a microscope slides so that we  could um study them um thanks to also professor   mark leake who heads the physics of of life  research group in york and also to gareth evans   who we're working with in trying to understand  which of these protein clusters are most toxic   i also need to thank alzheimer's research  uk um who have supported all of our work um   quite simply this work would not be  possible without their their funding   and i need to also thank the epsrc specifically  for funding lara in this in this work and of   course thank you for your attention i'm now  i'm very happy to take any questions thank you right well thank you very much indeed for that  absolutely fascinating i'm not sure i grasped   every subtle nuance of all the technical data but  i am going to ask you a question straight away   which i'm reasonably confident i will understand  the answer and that is you mentioned that today   the world's alzheimer's day can you just tell us  when that started why it was set up and and what   it aims to achieve our partners seem to talk like  yours on this particular date so alzheimer's days   is part of alzheimer's month and the the main  goal here is to ultimately raise awareness if i   put it into some kind of perspective the amount  of funding that's available specifically for   alzheimer's disease research is about equivalent  to one mile of motorway per year compare that   number with the funding that's associated with  cancer and heart disease hiv and stroke um the   amount of money that's available for alzheimer's  disease research is is utterly minuscule now   that's not to say it's not effective the money  that that is there but ultimately we need to   raise awareness of dementia-based research but  also the implications of dementia and alzheimer's   disease generally for the people who live with  alzheimer's disease and dementia and for those   who care for people with alzheimer's disease and  dementia because as i mentioned the cost is huge   not just to the person with the symptoms but also  to the the cost economic costs involved both to   families and to and to governments so alzheimer's  day is really about raising um awareness and   really you know demonstrating that this is a  disease that we understand we i mentioned at   the start that we have some open questions but  by and large we understand um what's going on   we understand these protein clusters exist and and  therefore a therapeutic is in sight and we really   just need to push towards that finishing line  now okay thank you very much now i've got two   questions from uh wolfgang and the first is i'll  give you both because i think they may be linked   the first one is how can you ensure that each  protein has its own fluorescent dye molecule   and then he goes on to ask can you ensure that the  inhibitor is not destroying the protein function so the to answer the first question how  do we ensure that each protein has its own   fluorescent dye molecule um so we can employ a  number of tricks and techniques during the uh the   purification process of these things we can try  to separate um free fluorescent dye molecules from   proteins but also labeled proteins from unlabeled  proteins and that works to to some degree   but really to identify whether or not every  single protein has been labeled we can perform a   technique known as absorption based spectroscopy  so really what that means is quantifying the   amount of dye that we have in our sample versus  quantifying the amount of protein that we have   in our sample and it seems based on our data that  we have a one-to-one labeling ratio in other words   the amount of dye present in our final sample  matches very well the amount of final and protein   how can we ensure that the inhibitor is not  destroying the the protein function it's a great   question many inhibitors many putative inhibitors  can interfere with proteins in other words they   can simply just change the the structure of the  protein and that leads to it not being able to   to aggregate but as i mentioned the beta amyloid  protein we think is part of the immune system so   it it's needed inside the body so we can't do that  with an inhibitor what we can do though is test   the amyloid function using a variety of different  assays and in this particular case the inhibitor   is not interfering with the function of a single  amyloid protein but but great great question   all right thank you um now i've got two again  two questions i again suspect they're related   from sandy divers and she asks how long will it  be until the process of research is available to   alzheimer's patients directly and or are human  clinical trials in process already please and   then link to that additionally are you able to  direct different procedures more specifically   for the previously acknowledged alzheimer umbrella  definitions e.g will the different alzheimer   definitions require different processes and to  be very grateful if you could um address those   so to to address the the point how long will it  be until the process of research is is available   to alzheimer patients directly um so a lot of  this work um has been used with my colleagues   and others as i've mentioned for the development  of a rapid blood test um so moving away a little   bit from inhibitors and understanding the disease  we now have the tools and techniques in place   at york to study single protein oligomers and  importantly to detect single protein oligomers at   really really really low concentrations now many  of the conventional blood tests can't do that they   they just don't have the sensitivity or the  specificity and our techniques do so what   we're trying to do at the moment is um build upon  preliminary data to build a blood test that we can   then commercialize and put into clinical trials  and we hope to do that within the next two years   this is all entirely dependent on funding we've  got many applications at the moment pending we're   very hopeful that this work will be funded we  hope that it will be funded and if it is then we   have a commitment to our funders to to get these  tools and technologies out there within two years   in terms of the um the inhibitor work  so we're if you like at the very very   early stages of the development of an inhibitor so  we're in the test tube and really to develop a an   inhibitor that will ultimately be used in humans  there's a number of different steps that have to   be fulfilled a number of requirements uh  number of boxes that have to be um picked   um so we're at the very early stages of that and i  would i would guess uh that from the test tube to   a clinical drug um would be around eight to ten  uh years um but the good news is that technologies   are evolving all the time technologies are getting  better and faster well as we know because of the   coronavirus um pandemic and we're now able to  screen for inhibitors much more effectively than   we were able to um several several years ago so  these timelines are constantly evolving over over   time and are we able to direct the procedures more  specifically to other forms of dementia yes the   the answer to that is we absolutely we  are using these tools and techniques to   investigate the building blocks of parkinson's  disease so we're looking at protein aggregation   um but not in the context of the beta-amyloid  protein but in the context of the alpha-synuclein   protein which seems to be a major hallmark  of parkinson's and in motor neurone disease   we now believe that the clinical symptoms  are related to the build up of protein called   and we're using our tools and technologies  again here to understand the building blocks   of motor neurone disease so absolutely  that's exactly where we want to go   thank you so that's a very encouraging  response now let's move on to andrew porra   and he asks how can you disrupt or  destroy the toxic stages of this process   without stopping the protein for putting  a youthful function elsewhere in the body   and this is the this is the million dollar  question ultimately um so we need the protein   we can't get rid of it we can't just simply stop  it from forming but equally these protein clusters   do seem to be to be to be toxic so the key goal  here is to block the toxic formation um now that's   not to say that the overabundance of the single  proteins could also happen and we could get even   more protein clustering after the let's say the  drug or the inhibitor has has gone in um it's   it's it's a great question um we we don't know  that we can't disrupt or destroy the um protein   function but i think i would take my chances with  disrupting the normal protein function versus the   protein clustering which seems as i've mentioned  to be orders of magnitude more more harmful   okay we've got a question from sue lister  who's asking this as a non-scientist   i think some of the question you may have  covered but i think it's such an important   area uh if you are repeating yourself i think  it's worth doing it right he says what is the   safe way to block the growth of dementia and when  will it be available to the nhs but before this   how and when will you be able to  test the free dementia symptoms   so right now as things stand there have been  over 300 believe it or not drug trials aiming   to identify an inhibitor a blocker if you like for  these these structures not one has been successful   in a clinical trial and we think it's because the  drugs are targeting the wrong structures we think   that the drugs are targeting the fibrils and the  plaques and stopping the fibros and the plaques   from growing even further they're not targeting  the oligomers and recent developments have seen   the at least in the test tube and in animal models  the development of inhibitors which do seem to be   um blocking the the oligomer so i think there's  there's promise there when will this be available   to the nhs um again it takes time for these uh  inhibitors to be fully validated um by i think   time scale that we're working on is is is on the  year's time scale um how and when may we be able   to test for the pre-dementia symptoms well i would  go one step further we want to really test for   the biochemical signals signatures long before the  symptoms actually arrive arise once it gets to the   point of having symptoms we think that the plaques  are formed so really what we want to be able to do   is identify someone who has no symptoms but who  is showing biochemical signatures um that comes   back to my previous answer of we hope to have a  blood test technology um in about two years and   we also hope to use the technologies of the blood  test to detect um proteins within the the urine so   not just a blood test but a non-invasive amp test  if you if you like it might be able to identify   whether or not you have more oligomers relative to  proteins in the body and therefore whether you are   exhibiting the earliest biochemical signatures of  alzheimer's disease such that we're in a position   a far better position to help slow those um  symptoms down because there are drugs available   to help slow the symptoms but there's not a drug  yet to completely block the alzheimer pathogenesis   all right thank you now i've got a very  different question from uh ben wagner who   asks on a personal level for you uh what made you  first pick up alzheimer's as an area to research   my grandfather uh had um dementia um he i'm sure  he had alzheimer's disease that was never really   clinically diagnosed and and part of the problem  is uh in large part because there is no diagnostic   test for alzheimer's disease but in in a sense his  his mind dies so names dates places his his entire   scrapbook his entire mind dissipated and and for  me that was really quite eye-opening and even more   so because there really was no treatment at the  at the time um so alzheimer's disease i think much   like peter it hits home um in oxford i studied  cancer-based research at mit in the us i studied   cancer-based research but i'll be on new tools and  technologies and now that i've studied a number   of different diseases using a number of different  tools and techniques we're now in a position here   in york to more effectively pinpoint and target  the earliest stages of alzheimer's disease so i   think um just to broadly answer your question it  was um you know a personal and relationship with   my grandfather that probably directed me into  the area of research i'm involved with now   all right thank you now i've got another question  from wolfgang and this question makes me suspect   you may know him um and he asks would there be a  benefit to measure the absolute concentration of   those proteins brackets regardless of the i think  it might he says dusting on its clustering stage   within a probe without single molecule detection  if so are there standard techniques at hand he   says hyperpolarized 129 xe might be there as a  tool at york there is also a great group working   on this i think your answer might perhaps unpack  a bit more of what he's asked there if you can   so so the answer is yes there is a benefit to  measuring the absolute concentration of protein   proteins because it's the overexpression the  abundance of these proteins that seems to trigger   the um the clustering process so in other words  the more beta-amyloid proteins we get the higher   chance of of clustering um more so than that there  are different lengths of the beta amyloid protein   and measuring the ratio between these various  lengths is thought to be an excellent indicator of   alzheimer's pathogenesis so specifically  um to answer your question um there's a a   beta-amyloid protein that's 42 amino acids long  there's another one that's 40 amino acids long   there's another one that's about 16 amino acids  long and yes measuring the absolute concentration   of those proteins in the blood in the urine could  be an excellent indicator of alzheimer's disease   the trouble though is that there is not a standard  tool for measuring picomolar concentrations of   proteins so really really tiny amounts of  proteins the best technique is a technique   called elisa that we have but the sensitivity  isn't quite there for the concentrations   that we think are in the brain um sub nanomolar  at the very early stages of disease pathogenesis   all right thank you i've got a question  from an anonymous attendee um and they ask   do you think environmental factors could  slow down the development of clusters   yes much of our work in the test tube does  show that environmental factors factors can   influence the the growth of these objects um so  specifically uh the the salts concentration the   local salt concentration that's surrounding the  the proteins influences and certainly speeds up   the the protein clustering switching the ph is  important so the more acidic the environment is   the faster the clustering um becomes now quite  how those environmental factors we can change   um is is a question that I don't have the answer  to is it related to diets we we just don't know   but certainly the local environment of the protein  does heavily heavily influence the development of   the the clusters now that's not to say that they  won't form um if the environment wasn't changed   or wasn't altered in some way and but there does  seem to be a link there between the growth rates   right i think we're going to have to wind this  up very shortly um i've got two more questions   so that's a quick answer to both of them if you  could and then we'll keep in our time limit from   linda she asks following your research do you  think pharmaceutical companies will become more   interested in developing provincial potential  preventative drugs and they have been lately   and actually the sense linked to that  is andrew porras come back with another   question at what stage is the most damage done  and can it be reversed rather than just unstopped   um so to answer the the first question i think  the answer is yes so for example johnson johnson   i know are particularly interested in developing  potential preventatives for not just alzheimer's   disease but dementia in in general they're also um  i know really interested in the technologies so in   the sensing technologies they want to send out um  blood test technologies to gps so that they can   more effectively know who's in the early stages  of disease pathogenesis so i think there's two   problems there first yes they're interested in  preventative drugs but they're also interested   in the technologies um now at what stage is the  most damage done so that's that's the question   that we're trying to really address we don't know  whether it's the trimers or the tetramers that are   more toxic than the dimers or vice versa what  we do know though is from our preliminary work   that some of these oligomers can punch holes  within the cells and when they punch holes   within the cells the cells or the contents of  the cells can be leaked to the environment and   that i'm afraid um cannot be cannot be reversed at  least in the test tube right well thank you very   much indeed i say you know a very very stimulating  evening it's wonderful to have this world breaking   research showcased for alumni forum and i really  do hope we can arrange some more of these i've   really enjoyed hosting it i've really enjoyed  listening to you and thank you for speaking to   us thank you for kyla for arranging all this and  her team that's made it all possible and thank   you for everybody who's logged on and listened  to the talk thank you again thank you on behalf   of the whole university to peter for hosting this  evening's event for us and to steve not just for   giving up his time as well this evening to speak  to us today um but for everything that he's doing   for the fantastic research and  encouraging news thank you very much steve

2021-09-29

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