FoundMyFitness - #035 Gordon Lithgow, Ph.D. on Protein Aggregation, Iron Overload & the Search for Longevity Compounds

Episode Date: April 4, 2017

Dr. Gordon Lithgow of the Buck Institute for Research on Aging tells us about worms! This unassuming scientific model has a lot of important advantages for science: they can be frozen and subsequently thawed and retain viability, they are extremely well understood down to the precise number of cells in their body and the wiring of their nervous system, known as the connectome. Additionally, they have a short lifespan and are cheap to work with. Why would that be advantageous, you may ask? This is where Dr. Lithgow's work on the Caenorhabditis Intervention Testing Program comes in. Short-lived organisms give Dr. Lithgow and his colleagues the opportunity to see how their biology responds to compounds in different contexts and to do so cheaply and rapidly. Think a vitamin, pharmaceutical or one of any number of other compounds may have a broad effect on longevity? Try it on Caenorhabditis first! Taking this approach allows the broad screening of compounds that might not otherwise get its chance in the limelight if science were limited to only working with rodents, for example. In this episode, you'll discover: (00:00) Introduction (03:30) What is C elegans and why do researchers use it? (06:43) Proteostasis and its involvement in aging (10:59) Shocking worms with heat extends their lifespan (16:40) Sauna use activates human heat-shock proteins, improving health (19:27) Excess dietary iron accelerates protein aggregation, promoting Alzheimer's and Parkinson's diseases (25:07) Vitamin D deficiency accelerates aging (35:19) Using worms to search for compounds that extend life in humans If you're interested in learning more, you can read the full show notes here. Join over 300,000 people and get the latest distilled information straight to your inbox weekly: https://www.foundmyfitness.com/newsletter Become a FoundMyFitness premium member to get access to exclusive episodes, emails, live Q+A's with Rhonda and more: https://www.foundmyfitness.com/crowdsponsor  

Welcome back again. Today's podcast takes a dive into the world of aging research, but from a perspective of lower organisms. Now, you may ask yourself, what do I have in common with something like a tiny nematode worm? And the answer to that is gene homology. In fact, Cinawaptitis elegance or C elegance as they are known, about 35% of their genes have human homologs, which means that a version is also found in humans. The beauty of a model like C elegance and aging research, as you will learn in this conversation with Dr. Gordon Lithgow is that these animals have a very short lifespan. That means that in comparison to more long-lived higher-order organisms like rodents, it's a bit more straightforward to change up the conditions and see what happens to their

lifespans. You can do this more quickly and more cheaply. By way of example, you might try adding in something like even a small amount of environmental stress, which if we're talking about heat stress, actually was shown to increase lifespan and worms when used in the right dose. A discovery that, as we'll discuss, Dr. Gordon Lithgow, Gow, today's guest, actually made in the course of his research back in 1995. But it's also practically useful for determining of certain compounds, including vitamins, may be candidates for increasing lifespan as well. This is where the Cinaweptitis intervention testing program comes in. The Cinaweptitis intervention testing program is a multi-institution effort sponsored by the

National Institute on Aging, a division of the NIH, designed to screen bioactive compounds for their ability to extend lifespan and enhance health using nematodes as a model system. for potential effects. The senior rapiditis intervention testing program is actually a spinoff of another program, more simply called the intervention testing program, which began in the early 2000s to look at the potential for various interventions, including vitamins and pharmaceuticals and otherwise, to extend the lifespan of mice. While mice are much more genetically close to us, sharing 92% of their genome in common with us, and discoveries are thus far more likely to have eventual clinical applicability, the cost and the time involved in screening is

also geometrically more expensive. Herein lies the value of doing broad screening with lower organisms like Cielligans, which can then potentially make its way up to mammal research and maybe if we're very, very lucky, clinical research in humans. All right, having rift on the value of research in lower organisms quite a bit, we can go ahead and get this podcast started. Quick reminder before we do that, though. This podcast was brought and paid for by amazing supporters. So in the place of the corrupting influence of more conventional advertisements, I'd like to ask you if you enjoy this podcast, you head over to foundmyfitness.com forward slash crowd sponsor. That's found my fitness.com forward

slash C-R-O-W-D-S-P-O-N-S-O-R crowd sponsor. From there, you can pitch in a pay-what- you can amount, in other words, any amount that you like, even a metaphorical cup of coffee, to support future episodes and the other various endeavors that fall, under the Found My Fitness umbrella. That means all the great stuff like my being able to travel to record on location as I did in this podcast or the YouTube videos that we produce from the interviews that are loaded up with helpful definitions and citations or the original content we produce. You get the picture. All that is made possible through this pay what you can subscription mechanism whereby each person pitches in as small or as much as they like and in doing so

becomes part of a community that makes cool stuff happen. So make sure to check that out once again, foundmyfitness.com forward slash crowd sponsor. Now on to the podcast with Dr. Gordon Lithgow. Hello friends. Today I'm sitting here with Dr. Gordon Lithgow, who is a professor at the Buck Institute for Aging. One of the cool things that I really like that Gordon does is that he actually screens various compounds, both natural compounds like vitamins and minerals and other compounds, to see if they potentially could be longevity compounds. And one of the ways he does this is by looking at the effects on a tiny nematode worm called sea elegance to see if there's any effect on their lifespan. So maybe you can kind of explain what are these sea elegans and

sure. Sea elegance is a tiny one millimeter sized roundworm. It's found in rotting fruit naturally. It's found on the backs of snails. And it's the amazing genetic system that was suggested by Sidney Brenner back in the 60s to study neurobiology and neuronal development. In the late 80s, it was adopted by Tom Johnson and Mike Class to look at longevity. And it's a fantastic system to study aging because, well, one, it's transparent. So you can actually see the tissues aging in real time day after day. But two, it lives a very short time. It lives about 15 to 20 days.

And that's the big advantage because you can go through lots and lots of experiments very, very quickly, fairly economically. And therefore, you can study lots of compounds and look for things that extend the lifespan. Right. As opposed to, for example, people that are looking at compounds and how they affect another model for eight, you know, and another model, like mice, for example. Yeah, I mean. How long do they live? Well, so a mouse in the labs living two or three years.

And it's incredibly expensive to maintain the animals. And, you know, these are million-dollar experiments to study longevity in mice. Whereas with the worm, again, it's very quick. And you can study lots and lots of individuals fairly economically. Yeah, it's super cool. I actually started doing my early, early research, right after I graduated from the University of California in San Diego, before I went to graduate school, I worked in an aging lab using Sieligan.

So I'm very familiar with them as a great model for aging. People fall in love with them, right? I mean, they actually come in and they're a little worm, but before long they're just devoted to all the biology and all the interesting things that happens. I mean, you're looking down the microscope and you're seeing all sorts of interesting behaviors, you're seeing growth, you're seeing learning and memory even, And then you start seeing this aging process taking over and one by one knocking back the functions that you can see. And it's really dramatic when you have a mutation or a chemical compound that stops that from happening or slows it down.

And people are just kind of amazed to see down the microscope a worm that's crawling around and behaving normally when it shouldn't be, when it should be dead. Totally. That's what sort of hooked me into this, you know, basically the field of aging was looking at these worms where you can get rid of. rid of their IGF1, you know, growth signaling pathway and literally can make them live 100% longer. I mean, it was incredible. And to think that this is the same pathway that's conserved in humans, it's like, well, that seems very relevant. Yeah. So, yeah, definitely that was the thing that got me really, really interested was that just, and seeing it myself, doing experiments, right? Seeing it in the microscope. It's really profound. So you do a lot of work on, these days, you're doing a lot of work on what's known as protein homeostasis, or I guess the word would be proteostasis, and how that's

involved in aging. I'm not sure most people watching or listening even have any clue why protein homeostasis plays a role in aging. Well, so as you know, we take in our proteins and we break it down into the essential amino acids and then we build our own proteins and the worm builds its own proteins, and those proteins have a three-dimensional shape, and that shape's important for function, of course. And during aging, the general observation is that that proteins lose their shape in various ways. For example, during Alzheimer's disease, the protein beta amyloid, loses its shape, undergoes various conformational changes,

becomes toxic, neurotoxic, but eventually ends up as an insoluble protein in amyloid plaques in the diseased brain. Now, that process happens in Parkinson's disease as well with a different protein, alpha-sinuclin, but actually we believe it's happening to thousands of proteins. And a few years ago, we published a paper where we showed that many hundreds of,

if not thousands of proteins undergo conformational change during aging and come out of solution. And it so happens that those proteins are enriched for proteins that determine lifespan. So when you're saying out of solution, you're saying so they're insoluble. They become insoluble. Can you at that point say it's an aggregate? Is that technically accurate? Biochemically, insoluability is related to aggregation. Aggregation is a coming together of that insoluble protein in a single foci.

So these, you're saying these aggregations or these insoluble proteins that are happening, you're saying hundreds of proteins that are happening with age this is happening. You know, this is partly because of damage that accumulates, correct? I mean, a lot of damage that damages DNA. So things like, you know, reactive auction species, inflammatory cytokines, these things are damaging our DNA, are proteins as well. Right. I mean, proteins sustain lots of damage in the normal course of metabolism.

But it's actually not too clear to us why this particular set of proteins come out of solution. And that's something we're pursuing and other labs are pursuing as well. Cynthia Kenyon's lab discovered a very similar mechanism around about the same time. And so I think we're all really interested as to why these proteins come out of solution and are enriched for proteins that determine lifespan. That kind of suggests that the protein of insoluability or misfolding or conformational change in itself has something to do with the aging process. And I think this is really important because here's a process that's been studied for decades in the context of neurological disease, Alzheimer's and Parkinson's and so on.

But if the same process is happening in the course of normal aging, it shows a connection between normal aging and disease. And that's something I think that lots of us are interested in right now. What are the mechanisms of normal aging that are likely to accelerate age-related pathologies and disease? Right. And if this is happening in not just our neurons, if it's happening in our endothelial cells that line our blood vessels, I mean, I often think about that as another, you know, tissue that is prone to, you know, insoluble proteins forming. I'm not sure if that's actually accurate. Right. No, I mean, there's the amyloids form and lots of tissues in our body, and there's very specific diseases associated with that. But I think what we're seeing is that this amyloid formation is a more general aging process. It's just going on probably in most of our tissues, if not all.

and maybe then drives disease pathology that becomes obvious to us when we look at it as a disease. So it's disrupting just normal tissue function, whatever tissue that is, it's disrupting maybe mitochondrial function, just, you know, the everyday things that are happening aren't happening as well, and this sort of can, you know, lead to or be part of what we call the aging process in a way. Absolutely. And, you know, and it's not to say it's the only aging process. It clearly isn't the only thing that's changing, everything is changing. There's evidence, for example, in Alzheimer's disease that there's a metabolic problem that happens before you start seeing aggregation of proteins.

So who knows how all these things interact with each other, but it's important. I think that's firmly established now that this is a major mechanism of aging. Right, yes. Well, I remember, gosh, it must have been like 12 years ago when I first read a paper of yours where I believe you may have been a postdoc because you were first author on this paper. And the paper was, you had found that heat-shocking worms. Actually, I think it was just at this early paper was a single heat-shock, and you increased a lifespan of the worm by like 15%.

And this was totally dependent on the production of something called heat-chalk proteins or HSPs, which people have heard me talk about before. And then you publish again showing that multiple heat-shock treatments could have increased the lifespan of the worm, like even more robustly. So could you maybe talk for, you know, just a little bit about, you know, how he chalk is this type of hormetic stress and how this can have beneficial effects? I remember when I saw this for the first time as a postdoc and I ran into the office of my supervisor, Tom Johnson, and they said, look at this. This is amazing. He stressed the animals and they live longer.

How is that possible? And he said, oh, right, you've just discovered something that John Maynard Smith published in nature in 1950s. And he pulled this paper, you know, he's drawn sure enough that John Maynard Smith, evolutionary biologist. had been looking at trade-offs between reproduction and lifespan, and he had stressed, in this case flies, stressed the flies with a heat shock and they had lived longer. And it was kind of amazing that this was in the 1950s, and this was before our understanding of molecular chaperones

and stress responses. And so they probably could never put that discovery into the context of the molecular and cellular processes that were going on. And what was going on was, the animals were being stressed, they're ramping up their defenses against misfolded protein. of course proteins misfold during the heat shock. And as a result, these defense systems are actually acting against the normal aging process, which is also the misfolding of proteins.

So it kind of makes sense to us now that these so-called hermetic responses are the production molecular chaperones, also ramping up of autophagy, the process of breaking down proteins. And a beautiful paper from Malene Hanson a few weeks ago showing at autophagy, autophagy is critical for this response to heat shock. So it's nice that things have come full circle and we've got a better understanding. understanding of what's going on there. It totally makes sense. So I mean, if you think about it, like you said, you know, in the case of heat, you know, there's lots of examples of hormetic stressors. I mean, heat's one, there's fasting. There's a lot of xenobiotic, you know, compounds or

zenohermetic compounds. Yeah. Cuman. These sort of things can, you know, they're slightly toxic in a small dose. And because of that small dose, I think dose is important. It activates, like you said, all these cellular stress response pathways that then help us deal with stress better. and guess what, aging is a stress. So, you know, you're not only increasing things that help proteins keep their three-dimensional structure, but you're increasing antioxidant pathways and inflammatory, just a whole host of things. And autophagy, you know, wanting to get rid or clear away damaged proteins, damaged cells.

And it's so funny, I hadn't thought about heat shock increasing autophagy before. And I was doing some background reading to sort of prepare to talk to you. And I came across that paper. And I was like, oh, this is. awesome, you know, because I hadn't thought about it. Melina told me about this before the paper was published, who's sitting in my office telling me about this, and I thought, ah, this is fantastic.

You know, and here's a mechanism now that really explains why a stress is actually leading to longer life. Yeah, and it makes perfect sense. Things like heat stress would increase, you know, the activity of machinery that we have to degrade proteins that are damaged like the proteosome. And it would make sense that autophagy, which is another pathway to do that would also be, also would be part of that stress response pathway. well. But what's really cool is that this is very relevant for humans, right? Because humans have

heat shock proteins. Yes. And our heat shock proteins are also responsive to heat. Absolutely. So, I mean, this isn't like just understanding worms. It's something that's, you know, being translated to humans. And actually, there's a body of literature about pre-stressing organs ahead of surgery that's very interesting and might be relevant to this. Where you know, there's just better recovery from surgery if there's been a pre-stress. Yeah. And similar literature on starvation or fasting ahead of various treatments for cancer, for example, chemo, yeah.

So we might not know all the details there, but absolutely, I think this is really important. It's probably a neglected area, actually. Oh, yeah. I think that, you know, Malina's papers brought it back to light that these stresses are anti-aging and potentially beneficial, and we need to think about how you would modify the stress in itself for humans. Obviously, we don't want to stress people. Stress is damage.

Right, no doubt about it. But can we harness that endogenous machinery that counteracts the stress? And I actually think that's what we're doing with a lot of the chemical compounds that we discover extend lifespan, is that they are either hitting pathways that regulate stress responses, or they are providing a sort of, we call it, I forget what we call it. Sorry.

I think some of the chemical compounds that we discover that the extend lifespan are actually doing this. They're harnessing the endogenous stress responses. Absolutely, absolutely. They're either activating the regulators of stress responses or they're causing a segmental stress. So you're seeing a limited stress response or only parts of the stress response are being activated,

but that's enough to give you beneficial effects. Yes, so I totally wanted to. mentioned something before you jumped into the compounds that was related to the heat stress, and that is there was a study, you may be interested in this, there was a study I read, was published not too long ago, just a few years ago, where people were looking at the heat shock response in humans that were sitting in a sauna. So, of course, that would be, you know, a way that humans can activate their heat shock proteins. So humans that sat in a 163-degree Fahrenheit sauna for about 30 minutes increase their heat-shock proteins,

including HSP-70 by 50% or baseline. And that was actually sustained for about 48 hours. So that elevation stayed for around 48 hours, which is really cool because it's kind of like a take-home while maybe we can activate our heat-chuck proteins from the sauna. And to sort of go one step further, because I've been sort of obsessed with heat-chalking in sauna probably since I started doing research many years ago

and I was working on heat shock a little bit in HSF-1 and all this stuff. But I recently went to Finland last November, and there's a researcher there. His name is Yari Lalkanin. And he's been doing, he's a MD PhD. He's a cardiologist, so a lot of his focus has been on heart health. And the sauna is something that is ubiquitous in Finland.

I mean, everyone has a sauna. Everyone. It's just ridiculous. So he does a lot of research on sauna. And he published a couple of studies that one came out in 2015 where he was looking at all-cause mortality in sauna use. So men, this was like 2,000 men cohort, men that had used the sauna like two to three times a week,

had a 23% or 24% lower all-cause mortality. Wow. Men that used it 4 to 7 times a week had a 40% lower all-cause mortality compared to men that only used it once a week. So it's like a dose response effect. But here's where you'll be interested. So he just published this paper last December,

same cohort of men. But this time he was looking at Alzheimer's disease. And what he found is that men that used asana two, three times a week, had a 20% lower risk of getting Alzheimer's. If they used it four to seven times a week, they had a 60% reduction in Alzheimer's disease risk, which is really kind of cool because it goes with your molecular mechanistic work and lower organisms on, you know, the protein aggregation and the heat shock and the stress response pathway. I spent most of my career just interested in worms. I mean, I thought if we can solve worm aging, that's fantastic.

Right. Over the years, this creeping realization that actually what we're doing, could be important for people as well, making all these connections to disease and all the model organism people coming to this conclusion, working on flies and mice and yeast even, that these are basic mechanisms of aging. They're likely to be playing out in humans as well. And therefore, we should do something with this knowledge

we've accumulated over the last 25 years. It's really time to try and translate that and do something that might be beneficial. Yes. Well, another thing that you've done, I think is very relevant, is your work on iron. So you had looked at how excess dietary iron affects, again, I think protein homeostasis. Absolutely, yeah, yeah.

Well, this was inspired by my wife, Julie Anderson's work on Parkinson's disease, where many years ago she published a series of papers showing how important iron was, causing damage to complex one in the mitochondria through redox reactions, and then that very specific damage would play out all the way to neuronal death, the doponergic neurons. So we went back and looked at iron. Basically, we had a collaborator, David Kililiah, who was able to show that iron levels become elevated

during normal aging in the worm. We thought, well, that's interesting because that's what happens in human brains and other tissues. And so we did a couple of things. First of all, we fed exogenous iron, so we increased the iron levels in the media, in the diet. That accelerated aging, so it shortened a lifespan, but it also accelerated the accumulation of insoluble proteins.

So it accelerated this sort of molecular pathology of aging. And the other thing we did was to feed the worms and a collator, an iron collator. And in that case, the iron levels did not rise during aging. And the worms lived longer. And it protected against protein aggregation as well. That was going to be my next question, actually. Yeah. So, yeah, so all sort of made sense.

Right. So the iron that you're feeding these worms, is there any way that it could be physiologically relevant to humans? like the levels that you were given them? I believe so. I think the experiments in mice with Parkinson's disease, for example, those are around about the levels that you could be exposed to, especially if you're working with metals, you're a welder or certain careers like that.

And the epidemiology suggests that indeed that leads to increased risk of Parkinson's disease. So I think coming back to normal aging, I wouldn't be surprised if these kind of levels of iron are important. the the are you familiar with the um there's a few gene polymorphisms and one is in the hemato hemochromatosis gene and people can get hemacromatosis where they're absorbing way too much dietary iron so that seems like it could be something very relevant if someone's homozygous for those polymorphisms in that gene it could be and it'd be interesting to to look at their aging characteristics and ask whether there's any sort of accelerated the aging phenotype there I know there's

all sorts of problems, so I wouldn't be surprised if there was. And there's also, what's so funny is I didn't think about, you're mentioning Parkinson's and how Parkinson's, you know, is associated with iron accumulation and the mitochondria, and this is, this, or damaging mitochondria, and this is leading to death of dopaminergic neurons. But what I was familiar with was Alzheimer's disease and how there's, I know there's, especially a cluster of polymorphisms, one is in the hemachromatosis gene, the other one's in the transferin gene, which binds free iron. Together, if you have like this right combination, I don't know how frequent it is in the human population, it occurs, people actually have a five times increased risk of Alzheimer's disease.

Yes. So there's definitely a connection between iron and obviously neurological diseases in general. And other metals as well. Other metals as well. Yeah, you've looked at some other metals, right? Yeah, and copper and manganese. And I think copper is probably critical in Alzheimer's disease. And again, this is possibly an underappreciated aspect of neurological disease,

partly because I think that it's difficult to think of ways to go after that as a target. So if you say, you know, we're going to manipulate the levels of metals. Well, you know, a third or a half of all proteins have metals as part of their active sites. Right. And the idea of treating a metal disorder is a little bit difficult to get your head around. And there are very few pharmaceutical companies in the world really go after metal. But, you know, I don't see why we shouldn't be asking the question, you know, can we modulate metals?

Can we modulate the activity of metal transporters in particular tissues? And can we prevent the elevation of metals and tissues during aging? That basic prevention of elevated levels of metals could be enough to protect us against disease. Yeah, absolutely. I think it's a very important question. You know, people are supplementing with all sorts of vitamins and minerals and some people are taking way too many, you know. Exactly.

You know, iron is something that I don't, I think, you know, people should get their iron levels measured. They shouldn't just be blindly taking an iron supplement. I mean, because that could be completely dangerous. Absolutely. And, you know, with these gene polymorphisms, like I always, it's sort of a pet topic of mine, so I'm sorry if I'm going off on this, but, you know, it's, we've sort of evolved in different regions, you know, across the globe, and there's different, you know, food availability, different minerals in the soil, things like that. And so we sort of like, depending on, at least this is the thought, depending on how much, you know, minerals were in the soil and all, you know, what type of food we had available, we sort of, you know, acquired certain mutations that became more frequent in the population, it became polymorphism.

So it may be some people, and you can see this when you look, if you look at, you know, a lot of different gene polymorphisms, a lot of them do have to do with minerals. They have to do with vitamin intake. And so all these things are sort of different people. And so I think it is very relevant to look at how this affects age. you know, for multiple reasons. So I'm actually glad that someone's doing it. Of course, the pharmaceutical drugs are always thinking of it from a different angle. And it may not be the way.

But it's all very important. But sort of to kind of go on to the next topic, you've also looked at vitamins. And I was very excited about your most recent, not most recent, but a recent publication of yours that had to do with one of my favorite vitamins, which is not actually a vitamin. It actually is a hormone. A hormone, yeah. But vitamin D. So you'd found some really interesting findings with vitamin D.

Yeah, we were looking at the C. Elligan strain that was engineered to express A-Beta, so human A-Beta. And when you do this in the worm, you see these tiny aggregates form, like mini plaques, and something about that is toxic and the animals become paralyzed. So this is in their muscle cells? It's in their muscle cells, although you can do the same in neurons as well. But it always makes the worm sick. So this was a strain created by Chris Link in Colorado.

And we were looking for chemical compounds that suppressed the paralysis. So very easy. You looked at in the microscope, but the worms are still crawling around after you've turned on the expression of the A-Beta, you've got something that's protecting against the aggravation process. And Carla Mark, a post-doc in the lab, conducted a screen on natural products. We'll look at all sorts of different libraries. This happened to be a natural product library.

And came to the office and said, hey, vitamin D. And we said, well, we're not going to work on that because there's a paper every day on vitamin D. And surely people have been studying vitamin D for decades. There's nothing new to learn about vitamin D. But the thing that intrigued us was when we started to look at the epidemiological literature and realize that when you're deficient, when humans are deficient in vitamin D, there are an elevated risk for many adult cancers but also neurological disease. And if you look at the spectrum of disease, you know,

it almost looks like many of the chronic diseases of late life. So I thought this can't be, is this possible that vitamin D deficiency is really some sort of accelerated aging? Is that what's going on here in people? So I thought, well, we may as well follow this because there's not a lot in the literature about A beta and protein confirmation and aggregation and so on. So we did many, many other experiments and found that indeed vitamin D had an effect, widespread effect on the proteome. So it was preventing protein insoluability, this age-related rise in protein insolubility, across hundreds of different kinds of proteins and different organelles in the cell and different tissues. So it's essentially

helping the proteins age better? Exactly, yeah, suppressing this phenotype of aging. And then we combine treatment with compounds or feeding with vitamin D in this case with different genetic backgrounds. And so we discovered that there's a requirement for certain genes, transcription factors. and these are transcription factors that normally respond to stress, and now we're back to stress. And it seems like vitamin D somehow is able to elicit the endogenous defense systems, detoxification systems. So it's turning on those systems. Like NRF2, we're like regulated? Right, that's right, yeah.

Yeah, the oxidative stress transcription factor in the RF2. It requires NRF2 in the worm to see the beneficial effects on the proteome. How weird. So we're following that up, but all this was new. for vitamin D. We began to show this data to some clinicians, experts in vitamin D metabolism and bone and so on. And they were really excited by this,

which is always nice when you study worms. Suddenly you've got a clinician excited. And I think they were excited because at the heart of it, you could see how an effect on a global process like protein aggregation, which is associated with lots of different diseases, could explain perhaps why vitamin D deficiency is associated with neurological disease and other diseases.

So it almost like was giving them a handle and a potential mechanism that might explain a lot of what's going on in the epidemiological data. And we thought it was cool because when we talk about vitamin D to our colleagues or our friends or the general public, there's a response. People are interested in it.

It's cheap, it's readily available. Many people are already thinking about it in their own health. And so it makes a connection between the, you know, the curiosity research we do in worms and actually people's lives. So we're enjoying working on it. Very cool. Well, I have a thousand questions about that. So, I mean, obviously the question you probably get from every single person that you talk to about this research, and that is, okay, so do the worms make vitamin D? We make vitamin D in our skin from UVB radiation.

Correct. I always thought of the worms as being soil dwelling, but you mentioned beginning in the podcast that they actually are on fruit. Right. So potentially they are exposed. They probably are exposed to light. Now, water will run away from light. If you turn the UV light on in the microscope, they'll move. But they probably are exposed to a certain amount of light. Now, do they make it in the wild?

We don't know. What we do know is that if we feed D3, which is the metabolite you buy at the drugstore, D3 is converted into 125 dihydroxy vitamin D. So there's two steps, one in the kidney, one in the liver in mammals, that does that conversion. Now, we know if we feed the worms D3,

they are able to make the 125 vitamin D. So we think that there's conserved metabolism between mammals and worms. That suggests that maybe the worms are really making it in the wild as well. They've got the apparatus. They've got the enzymes. We also know that they have the precursor to vitamin D that we have in our skin

that we turn into D3. They've got tons of that in their tissues normally. We actually feed the worms cholesterol. Really? Oh, they have seven dehydroxyclosterol. They do. They have seven dehydroxy cholesterol in large amounts. So our expectation is, and we'd never really been able to think how to do this experimentally, but if we took worms from the lab and took them outside into the sunlight,

we might be able to detect them making 125. Well, why don't you just, there's a couple of experiments I would think about is one shining UVB on them, right, and seeing if that works, because that's how we do it. Yeah. So UVB radiation hits the seven dehydr cholesterol, and then that's converted in vitamin. D3, that gets transported in the bloodstream, and then two hydroxylation steps later, you get the active hormone. Right.

So that could be one thing you could do. The other thing is, did you guys try feeding one 25 hydroxy vitamin D? We did. Actually, we fed a whole bunch of different metabolites of vitamin D. And basically, any metabolite that can be converted into the active form is beneficial. Okay. Cool. So that sort of makes sense.

It makes sense. Yeah. You'll be interested in know, if you haven't already seen this literature, because I also have published on vitamin D and very obsessed with it. Are you familiar with the work that was published? Geez, must have been like 10 years ago now, but on the vitamin D receptor knockout? Yes, yes, yes, yes. Have you seen those animals?

I've never seen them personally, but I've certainly right about them. Well, at four months of age, they're both, you know, if you have normal wild type mouse and you knock out the vitamin D receptor and then you look, four months, they look the same age. And then eight months, that mouse looks like a progeri. I mean, it doesn't even look like a two and a half year old mouse would normally look. It looks like some sort of progeria kind of phenotype where there's no hair. The skin is all wrinkled. Their organs are all like shutting down.

I mean, it seems like a very progeria type of phenotype. I don't know if that's... Certainly the papers suggest that and there are specific measures that are absolutely in keeping this normal aging. There's probably a lot of other things going on as well, I imagine. Yes. When you really seriously mess up vitamin D metabolism, it's going to have lots of effects. given. Yeah, but absolutely.

It was very exciting when we went back and looked at those papers and thought, oh, this could make sense. Right. And there's also, like, if you look at the epidemiology stays in humans, we know that, for example, there was a very large meta-analysis, like 33 different studies that were looked at, ranging from, you know, the year 1960s all the way to 2013. So broad range of time, looking at people's blood levels of 25 hydroxy vitamin D, which is the precursor, and it's the most stable form. And what the research, the meta-analysis found is that people that had blood levels

between 40 and 60 nanograms per milliliter had the lowest all-cause mortality compared to those that had lower vitamin D levels or even really, really high ones. But we also, there's some randomized controlled trials that have looked at giving people high-dose vitamin D supplementation like 4,000 IUs a day and an improved cognition. Whereas low-dose did not like 400 IUs a day would be considered low-dose. That did not have no effect. So I think there's certainly, there's a lot of evidence, associative studies, and also there's some randomized controlled trials that really does point to the fact that vitamin D is regulating

the aging process. It's been shown to regulate telomere length. I think that it's absolutely probably regulating the aging process. And this whole like protein aggregation angle is new to me. I didn't know that it really played a role in that. And that's super cool because I do know that protein aggregation plays a role in the aging process. So it kind of, you know. It's beginning to join up into a.

a sensible story. Now that said, we should be cautious. And I'm not an MD and I'm not prescribing vitamin D for anyone. Although it's likely that if you're deficient, you really would benefit from coming up into a sensible range. High doses, and these are usually very high doses as a result of some accident, but obviously it causes mineralization and that can be serious. And so, you know, I think it's up to people to talk to the physicians about it,

to get tested perhaps for levels, it's probably almost completely harmless to be taking an additional thousand units a day on top of whatever's in your diet, but really talk to your doctor about it. I think that's excellent advice, and most people don't get their vitamin D levels measured, and I think that's exactly what people should do.

They should get their D levels measured before and after supplementation, both. I mean, it's not a hard test to do. If you have health insurance, it's covered. If you don't, it's still really cheap. I've done it. You know, it's not an expensive. of tests and it's very worth it. So I agree that it's very important to get your levels measured

and you don't want to just blindly start taking like 20,000. Yeah, especially if you're a CLEGANS. Okay, so the last thing that I want to talk to you about that is really super cool that you're doing is you're involved. I know that the NIH set up this program that was like this intervention testing program in mice, right? That's right. And they were looking at compounds that could potentially affect longevity in mice. But in parallel, you're doing something really cool in worms? Yeah, I mean, the mouse program has been very successful. Rapamycin was the drug that emerged as being robust and reproducible at all three sites where these experiments were conducted in mice. But a few years later, I guess it was a feeling that maybe we can accelerate this

if we utilize the speed of the worm and also utilize the great genetic diversity in Cinerobditis itself. Cinearabditis is found all over the world, has incredibly large genetic diversity. And the thinking there is that, well, if you can find compounds that work in not only different labs to the same extent, but also different genetic backgrounds, then you've maybe got a high value candidate to then take forward into a more expensive mouse study. So, yeah, so it made perfect sense to us. We were very fortunate to be funded with Monica Driscoll and Patrick Phillips, the other two investigators involved in the study. It's a large study with lots of people in all of our labs. and we were, we sat down for the first time to talk about doing worm aging experiments and to work out how are we going to do this so that we're all doing the same thing.

And we were horrified, absolutely horrified to see the differences between labs in protocols. It needs to be the simplest experiments in the world. You take worms, you put them on an agar plate, you squirt a compound on there, you watch them every day until they all die. It's the simplest thing in biology. except we were all making our plates differently, growing our bacterial food differently, handling our worms differently.

Everything was different. So it actually took us over a year to standardise the protocols and start to see similar results. Even without treatment, just growing worms and measuring aging. It took us about a year to really get that down. But then we had this wonderful platform where we could go in and say, well, let's test some of the compounds that are already out there

and published, and let's test some compounds that have been looked at in the mouse studies and ask, are they robust and reproducible? And the results are mixed, to be honest. We are able to find reproducible and robust compounds that work in lots of different genetic backgrounds and extend lifespan in all three labs. But we find also a great degree of variation

and different kinds of variation that we'd never imagined before. So I think it's proven to us that this is difficult stuff doing this, And we really need to pay great attention to the protocols that we're using and be able to communicate those and convey them to other laboratories if we expect other people to be able to reproduce our findings. And what sort of compounds are you? So there's like a top 10 compounds that you were looking at? Yeah, I mean, we selected 10, as I said, just to get started.

And those included some compounds that we had published, including thioflavin tea, which is a compound that binds amyloids. And we hoped, and we think it does, promote protein homoestasis as the result of this. It also turns on stress responses, as we're talking about earlier. So thiety was one that we felt was going to be robust. It turned out it was. It was robust and reproducible. So that extended lifespan of C. Elegans? Yeah, C. Elegans and all the other... C. Briggs-e and other species. See tropicalis and other species. Wow. And there were some compounds that did really well in Elegans,

where they were first published, but actually didn't then do well in Briggs. So there could be many, many reasons for that, but it was kind of what we expected that different genetic backgrounds will respond differently to a compound. And we found compounds that really didn't do anything at all under our protocol. Now, that's not to say they don't work in someone else's hands in their protocol, but now I think we've got a deeper understanding of the major effects of just subtle changes in the way we do experiments. So they don't work in their hands, but that doesn't mean they're not promising candidates. It just means we need to think more about what conditions they're going to work in.

It seems like the compounds that are working in multiple different species are probably, you know, the best candidates, in my opinion. But, you know, the ones that are at least working in some species are also seems. I think alpha-kidogluterate was another one that is in some. Yeah, it's doing really well. I mean, it's great when you just, you go to a paper, you know, really great paper that you like and you just are able to reproduce it. It's fantastic. Yeah. So alpha-quitigliterate was one of those candidates.

And, yeah, I mean, I think we also want to invest. why compounds do not work in particular strains because that could tell us something about genetic specific responses to compounds. And this may become important as you move towards humans where there may be particular metabolic pathways that we want to avoid engaging or we might have genetic information on that would suggest we shouldn't be treating this group of people. Right, exactly. Personalized medicine sort of interaction between genes and compounds and there's lots of interactions between drug metabolism, like way metabolized drugs and, you know, the genes that we have.

So that's what can actually make sense. But so the next step then is once you, so if you have these compounds that seem very promising that you've identified in the various species of worms, is that do you like communicate to the mouse community and they sort of potentially will look at those? Absolutely. I mean, we will publish everything positive and negative with respect to lifespan effects.

Also health span. We're looking at health span. How do you do that in worms? Well, you know, that's a big debate right now, as to how to do that. Of course, the worms are changing their behaviors as the age. They're becoming slower. They're eating less. They cease reproduction. Eventually they become paralyzed, essentially not moving at all on the plate.

So there's plenty of things to look at. Also, their tissues are changing, and you can look at the tissues themselves. And really, we're just kind of sorting out what the best parameters might be right now. resistance to stress, for example, goes down with age. And so maybe we just look at resistance to stress at multiple ages and asks if compounds are able to maintain that resistance. What about compounds that are able to really work well when you stress the animal? So let's say you have a compound that is, you know, something that's like a xenohrometic kind of compound, which you may see a very small effect on lifespan just under normal aging conditions.

But what if you were to like stress them, you add some sort of oxidative stress or something, and then you see a really robust. Like, do you think you might be missing some of those sort of compounds? I believe so. And I think that they might come out of our next series of experiments where even where we have a negative result on lifespan, we will look at health span. We'll look at stress responses and ask, well, is this something that's really making the animal healthier for longer, which of course we're interested in, but maybe just fails to increase the maximum lifespan? Can I give you a, can I put a bit in for a compound? you should look at. Sulfuriphan.

Okay. Sulfurphane is, are you familiar with sulfurane? Nope. Okay. All right. So sulfurophane is a xenohrometic compound. It is produced in cruciferous plants. So, you know, anything from broccoli to kale to California.

Yes. I remember now. So it is produced when the plant is, you know, crushed or broken, and it comes in contact with an enzyme called myrosanase, and then you produce sulfurophanees. So, ferruphine is, to my knowledge, the most potent dietary, naturally occurring dietary activator of NRF2 pathway. I've done a lot of reading about it. I've interviewed Dr. Jed Fahy, who's at Johns Hopkins, who worked with Tallulay, who

sort of discovered that it was the activator of this whole NRF2-Keep-1 pathway. So I'm sort of really familiar with the field, and I was doing a lot of reading trying to figure out, because in humans, there's been a lot of clinical studies in humans showing it lowers inflammation, biomarkers of inflammation in humans. It lowers biomarkers of oxidative stress in blood cells. It affects glutathione. Just everything, right? And all sorts of cancer prevention studies, just, you know, Alzheimer's disease in animals.

I mean, lots of animal studies. But I couldn't really find any lifespan studies, and I was looking specifically for Drosophila or Skelligans or something. And I came across this paper that was published in, like, red flower beetle or something. I'd never heard of it. Anyways, they fed these red flower beetles sulfurophan. and it extend their lifespan. And then they did some oxidative stress

and it really robustly extended their lifespan. So I would be really interested to see if it doesn't. I mean, I would bet that it does something in C.L. That's very cool. So sulfurophane. Okay. I'll send you an email. Please do.

And actually, you know, we are really interested in hearing stories like this and we want other scientists and other people to make suggestions to the consortium for testing compounds. We have another 10 that are in process right now, but this is going to continue for the next few years, and we hope to get through hundreds of compounds eventually. So we're looking for suggestions. Definitely one. Yeah, I would love to see.

I mean, really love to see it. So that would be super cool. Well, Gordon, I really, thank you so much for taking some time to speak with me about your research and, you know, how you're, you know, trying to look at all these various, you know, pathways as they relate to aging and protein homeostasis and these compounds that may extend health span and lifespan and lifespan, all very relevant to us, you know, down the line. So pleasure talking with you today. And if people want to find you, they can find you at the Buck Institute for Aging.

Absolutely. And if you want to learn more about your research, you'll be there. That's right. Thank you very much. Bada-Bum. That's an episode. Thanks for listening. For those of you that have done 23-me genetic testing and are interested from a non-medical

informational-only standpoint in learning about whether you might have some of the specific combinations of gene polymorphisms discussed with Gordon in the transferin gene and the hemochromatosis gene, you can actually find out what your genotype is by running the raw data through the tool on my website. It's very easy to do and very quick. Learn more about that at FoundMyFitness.com forward slash genetics. That's G-E-N-E-T-I-C-S, genetics. From there, you can also learn about certain genes involved in fat metabolism, vitamin D metabolism, omega-3 fatty acid metabolism, vitamin A metabolism, and more. Lots of really cool stuff and I plan on continuing to add even more great reports on there as time goes on. It will only get better. So make sure to check that out once again

at foundmyfitness.com forward slash genetics. If you're interested in receiving notifications about the very best podcast, expanded show notes, articles, and other information I publish nowhere else. Also make sure to go sign up for my email newsletter, also found at my website. And finally, if you love this podcast or any of the cool stuff brought to you under the Found My Fitness umbrella, you can learn how to support it for as much or as little as you like, even that metaphorical monthly cup of coffee or bundle of kale by visiting FoundmyFitness.com forward slash crowd sponsor. That's foundmyfitness.com forward slash CROWD S P-O-N-S-O-R.

Until next time, may your telomeres be long and your DNA repair enzymes be strong. Dr. Rhonda Patrick over and out.