Illuminating Alzheimer's: shining a light on York's search for a cure
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 19:57
