Erin Spain: You're listening to Breakthroughs, a podcast from Northwestern University Feinberg School of Medicine. I'm Erin Spain, executive editor of the Breakthroughs newsletter. Deep in the heart of rural Indiana's Amish country, a medical phenomenon has been discovered that some are calling the internal fountain of youth. Among a community of old order Amish in Berne, Indiana are carriers of a genetic mutation that seems to protect against aging. They live 10 percent longer and seem to live healthier lives, from a variety of perspectives, than those without it. Dr Douglas Vaughan, the chair of the Department of Medicine here at Northwestern, has been studying this group and the protein associated with their mutation. He's now working on a new drug that may offer the anti aging protections found in this unique population. Thanks so much for joining me today.
Dr. Douglas Vaughan: Delighted to be here.
Erin Spain: So your journey to researching this extraordinary group of Amish people is pretty fascinating and I want you to tell us more about that. But first, how did you a cardiologist become so interested in aging?
Dr. Douglas Vaughan: Well, I first became interested in it as a human being. I'm looking in the mirror every day. I think all of us get more interested in aging as we move along in our lives and I think that's a background for me. It's probably a background for anybody to be interested in aging. The reality is in in 2019 the curtain on aging is being pulled back. There are a remarkable set of advances that have helped us to understand the biology of aging over the last 20 years, so it's one of those phenomenon that we all experienced. It's likely that we will be able to address aging in a tangible way in the next decade or two. So it's a pretty interesting space to be in.
Erin Spain: And as a cardiologist you see people come into your clinics and you see people as in your role for the department of Medicine with all sorts of ailments and age is the biggest risk factor for a lot of these.
Dr. Douglas Vaughan: You nailed it perfectly. Age is the most important risk factor for cardiovascular disease. It's also the most important risk factors for most of the common maladies that affect us all. Whether it's neurodegenerative disease, metabolic disease like diabetes, lung disease, cancer, all those occur more frequently as we age. So there's something about aging that reduces our ability to deal with or prevent changes, for example, in our blood vessels that promote cardiovascular disease.
Erin Spain: And as you said, there are things every day in the news it seems like - there's anti aging stories, but lifespan is pretty complicated when it comes to, as a human trait.
Dr. Douglas Vaughan: Oh, it's very complicated and there are so many different factors that get involved with it. We know that they're likely to be genetic factors. We all know we're aware of families that have short or long lifespans. There are groups of people around the world that have relatively short or extended lifespan. Sometimes it's attributed to genetic factors. Sometimes it's an attributed to environmental or dietary factors. It's extremely complex. And any of us, when we think about how long we might live, we have to not only think about the biological factors of it, but there's luck is also involved. You know, you have to to live long, you have to not step out in front of a bus sometimes too.
Erin Spain: So you are a physician scientist. I mean do you see patients in the clinic, but you're also studying this in the lab and you've created a pretty unique mouse model to study aging. Tell me about this model.
Dr. Douglas Vaughan: You know, over the last 20 years, several different groups around the world have engineered lines of mice that display changes, accelerated changes over time that look like aging. We've been using a mouse that's called Clotho. Clotho was one of the Greek goddesses who would determine lifespan with a couple other goddesses as well. And so a group in Japan first engineered these mice and actually they made it accidentally. They were making a transgenic line of mice and they were popping a gene into the mouse genome and it happened to land in a gene that had never been described, and when they saw the mice and they started breeding them, they were surprised to see that they manifested changes very rapidly that looked like aging. For example, they didn't grow to be very large. Their lifespan was markedly truncated compared to a normal mouse, a normal mouse in an experimental setting at a university like ours will live about three years if you don't bother them. These Clotho deficient mice live about 10 weeks. Just about the time I moved to Northwestern in the early 2000's, it was reported that Clothe deficient mice and mice that had this rapid aging phenotype show an alteration and increased expression in the protein that my laboratory has been working on for the last 30 years. It's called plasminogen activator inhibitor type one or PAI-1 for short
Erin Spain: For about 30 years - you've been studying this?
Dr. Douglas Vaughan: I have been studying this, but more from a perspective in its role in cardiovascular disease and thrombosis. Now it turns out in the, in the mid 1990s, several groups around the world identified the fact that that PAI-1 is a marker of cellular senescence, now what is that? As we age, our cells in our body becomes senescent. That means they lose their ability to regenerate and proliferate and we lose our reparative potential as we age. So one of the key drivers of aging in all mammals are all animals, probably, is this process of cellular senescence. It turns out PAI-1 is part of the molecular fingerprint of senescence. We took those separate observations that PAI-1 is involved in senescence. That PAI-1 is increased in animals that age rapidly. And we said, "Why wouldn't PAI-1 be one of the drivers of aging?" So that's the experiment that we did and that was work that we did here at Northwestern. Long story short, it turns out that PAI-1 was a major contributor to the rapid aging phenotype in Clotho. If we took PAI-1 out of a Clotho deficient mice, either both copies of the PAI-1 gene or only one copy of the PAI-1 gene, we quadrupled their lifespan. We saw that they were protected from emphysema. We saw that they grew up in a much more normal way. There were much more active. We restored the fertility and some of the mice, even by taking PAI-1 out of the equation and overall they were just much healthier animals. Now the question is - is that really affecting aging or is that just effecting some biologic processes that look like aging? And that's a big question,
Erin Spain: It was your study of PAI-1 that led you to Berne, Indiana and the Amish community there. Tell me about that connection and how you ended up in Indiana in this Amish community is studying a phenomenon there.
Dr. Douglas Vaughan: In the early 1990s, there was an interesting little article published in the New England Journal of Medicine about a young woman and her family that were members of this old order Amish community in, around Berne, Indiana. The kindred was originally from Switzerland. They've been in Indiana since the mid 1800s. Anyway, this little girl was described in the New England Journal of Medicine. She had an odd bleeding disorder. She wasn't a hemophiliac. She didn't bleed spontaneously, but after she was injured or if she had minor surgery, she would form a clot just fine. Her primary hemostasis was perfectly intact so she wouldn't bleed then, but a day or two later she would start oozing and a very astute and clever hematologist in Indiana was asked to see this young woman and she worked her up in all the kinds of ways that you would work up someone for a bleeding problem and couldn't find anything. The only thing that they could find at the end of the day was that she had no PAI-1 in her blood, so they ended up getting her the gene codes for PAI-1 sequenced at the University of Michigan and it turns out this little girl had a premature stop codon in the gene. She had a known mutation and she had two copies of the known mutations show. She was homozygous for this, for an alteration in the gene that codes for PAI-1, so she had no PAI-1 in her blood. Turns out she had a brother with the same problem. She had some cousins or two with the same problem and that this was how this was described.
Erin Spain: And this is unique to the literature? This had never been seen before?
Dr. Douglas Vaughan: This had never been described before. PAI-1 wasn't really even discovered until the early 1980's when there was a big push and development around creating or developing a new drugs to dissolve clots in the body. TPA is the one that came out of that push in the mid 1980s and that's a drug that was discovered and described in a lab in Belgium. It was licensed to Genentech. They developed the first recombinant drug used in human medicine. TPA is still used today to treat strokes and heart attacks. It activates your clot dissolving system. PAI-1 is the natural inhibitor of our own TPA. That's how it was known in the 80s and early 90s. And no surprise, she had this weird bleeding disorder because her clot dissolving system worked too well.
Erin Spain: You saw this at the time when it came out in the New England Journal of Medicine - this was, sort of, your protein. What happened next? How did you end up going to her community?
Dr. Douglas Vaughan: I had a lingering desire to go study that population in a way, but I didn't have a very well formed hypothesis about what I would test. In a generic sort of way, I just wanted to go study their cardiovascular system, trying to understand if PAI-1 impact on blood pressure or atherosclerosis and things like that. But that's not a very robust or valid way to go test the population. I kept the idea in my mind that someday I wanted to go. I wanted to have an opportunity to go study this very unique population. And you already mentioned it is as far as we know it's unique in the world that there's a, a community that harbors this mutation. Let me just say a couple of other words about it. The the original founder of the mutation can be traced back to the mid 1800s. He married into the community around that time. He and his wife had 10 children. They had 148 grandchildren. Every carrier of the mutation that can be identified today is a direct descendant of that original founder.
Erin Spain: So that took some genealogical work on your behalf as well?
Dr. Douglas Vaughan: Six or seven generations into it. Actually, it took that many generations for the first homozygotes to appear. They don't marry their first or second cousins, but anybody that carries the mutation is at least remotely related. So this is true of the first homozygous young woman that was identified, her parents were distant relatives. And it's true for everyone that carries the gene. Now we don't know, there are probably 20,000 members of the extended Amish community in two counties in eastern Indiana. They have not been all genotype by any stretch of the imagination. We think the carrier rate might be as high as 10 percent in the group as a whole, but only about 500 individuals have been been genotyped at this point in time. We know that there are at least several hundred carriers of the mutation. There are only 11 homozygous individuals for the mutation and the oldest one is that young woman who was described in 1992. Now she's in her late thirties.
Erin Spain: And you know this number because you went there, you took a team from Northwestern to this small community in Indiana and started the research and as you said, this was something you had been wanting to do for a long time. How were you able to assemble it and do it?
Dr. Douglas Vaughan: Well, there were several components. There was the intellectual component and coming up with a hypothesis that was testable and also there was having the right amount of have preliminary evidence that this would be a worthwhile undertaking. So our studies in the Clotho deficient mice were really pivotal in this regard. So we showed in the Clotho deficient mice - if we simply took out one copy of their PIA-1 gene, we protected them from an aging like changes. We hypothesized that the carriers of the mutation in the Amish population might be protected from aging in some kind of way and knowing that there were potentially lots of heterozygotes or carriers of the mutation we had a basis and there were some kind of probability that we could actually answer the question. So we put together an application to the national heart lung blood institute. We hypothesize that carriers of the mutation would be protected from aging in some measurable or quantifiable way. Now the interesting question is, how do you measure aging in a human being? I mean, how do you measure biological age versus chronological age? You know, we all spin around the sun but our biological age doesn't necessarily correlate with our chronological age. So there are lots of potential ways you can measure. There are things that clearly changed over time in all of us. And so we put together basically a short list of measurements that we intended to do in the population to test their biological age. We combined that with some molecular markers as well that speak to biological age as well.
Erin Spain: So you have these things you wanted to do, but not just anybody can waltz into an Amish community and say, "Hey, I want to collect some of your DNA, your blood." How did that part of it work?
Dr. Douglas Vaughan: Well, this is a really important part of the story and it would never would have happened without collaboration and partnership with Amy Shapiro, who is the astute hematologist who first identified the young woman with a bleeding disorder in the early 1990s and her partner Dr. Shweta Gupta. They practice hematology in Indiana. I knew Amy from the world of thrombosis. I talked to her at scientific meetings over the years. I called her up and I said we have a hypothesis that the carriers of the mutation might be protected from aging. She was very excited about the idea. She gave us an intro into the community. She and her office staff and her partners invited 300 members of the Amish community to come have a series of tests done. In May of 2015 we went over there, we took a group of 30 individuals from Chicago, we took over all kinds of tests for all kinds of equipment from centrifuges to echocardiographic machines and we set up camp in a recreation center in the fields in and around a farm field near Berne, Indiana. We brought 177 members of the community through in a two day period. We performed a variety of tests on them and included everything from a measuring, taking blood samples to measuring their blood pressure.
Erin Spain: And it's important to have mentioned all of these people are pretty healthy. Just the lifestyle they live, which is sort of a mid 1800s lifestyle.
Dr. Douglas Vaughan: Yeah. They live a very vigorous life. You know, this particular group of old order Amish don't use combustion engines. They don't use electricity. They get around by horse and buggy. They dress in a traditional way. They even speak to each other in a traditional low, low German dialect. It's a remarkable natural experiment if you think about it for a minute. So they are sort of geographically located in a relatively restricted area. They interact with each other around this community. They tend to live their lives in their community and marry other people in the community. So they're relatively genetically isolated compared to the typical American and all the other things that might impact on things like aging. Diet? Well, they all have the same kind of diet. Environment? They all live in the same area. They all of them kind of do similar work. They all look similar degrees of education. They all have the same religion obviously. They all wear the same kind of clothes. So you're randomized at birth. One of the things that you are just by a natural experiment to being a carrier of this mutation or an individual that doesn't carry the mutation. And then you can ask questions about how does this impact on the physiological changes that occur with age.
Erin Spain: As a scientist and a physician, what was that experience like for you?
Dr. Douglas Vaughan: It was unbelievable. It was the most exciting moment of my whole career to be able to go and interact with them and talk to them and perform the study. We had a hunch that there might be something there but, we didn't know. Mice are interesting experimental models, but they don't necessarily speak to the complexity of human disease. Originally, we were relatively simplistic in our perspective on age when we wrote that grant a few years. We decided our primary endpoint would be a molecular marker of age that's called telomere length. So in all of us - the ends of our chromosomes shorten as we age as ourselves go through proliferative cycles. The telomeres shorten and actually there are commercial vendors now out in the world that will measure your telomere for you. Telomeres predict your lifespan. They predict how long you're gonna live. The length of your telomere predicts whether or not you're going to get cardiovascular disease or diabetes or cancer or neurodegenerative disease. It's a pretty interesting molecular marker. So we set out as our primary end point telomere length. We thought the PAI-1 mutation might impact on telomere length and secondary to that we ask things about their metabolic efficiency, their cardiovascular system and their lifespan, how long they lived.
Erin Spain: And the results are pretty fascinating and they got a lot of attention - some of the findings. What you published in science advances, we're not only on aging, but the healthy aging of this population carries of the mutation lived to about the age of 85, which was 10 years longer than their peers. And the carriers had no type two diabetes at all and their peers had about seven percent. Why are those findings so important?
Dr. Douglas Vaughan: Let's talk about diabetes first. I think there's a community of individuals across the world that studies the biology of aging embraces the idea that insulin or insulin related peptides and signaling is one of the drivers of aging. It's certainly true in worms and flies and probably mice, and it's likely to be true in human beings too. So the reality is, what we found was that the carriers of the mutation actually have lower insulin levels than their uninfected counterparts. Their fasting insulin levels were about 30 percent lower and that's controlled for their BMI and that's controlled for their diet and their age and their gender. They're more metabolically efficient than individuals that don't have the gene mutation. As you mentioned, we've not seen any evidence of diabetes in the carriers of the mutation we followed them up since the time we originally did the study a few years ago. We've added a few more carriers to the group that we've seen overall. We've still not seen one develop diabetes. That's pretty unusual in an American. So we think that's probably one of the key contributors to the molecular effects of this gene mutation that impact on aging now they're tilomeres are 10 percent longer too. That would sort of predict a 10 percent longer lifespan theoretically and that's actually what we saw when we went back into the geological records of the community. When we can identify clearcut case and controls and looked at their lifespan. It looks like the carriers of the mutation actually live about on mean about 10 years longer than their uninfected counterparts. That's probably about all you could ever, ever expect from a single gene mutation in a human being.
Erin Spain: And you're actually taking some of these findings into the pharmaceutical realm possibly to develop a drug that could support healthy aging. Tell me about this drug. Where's it at in testing right now?
Dr. Douglas Vaughan: About 10 years ago, I was contacted by an academic research group in Japan, Tohoku University. A professor named Toshio Miyata. Toshio subsequently became my friend and partner in a variety of investigative activities. Toshio is a nephrologist. He and his group were interested in developing a drug that could block the activity upon one because of its role in kidney disease. So they came up with a prototype, a small molecule that you can take by mouth that will be orally active. And he contacted me and said, would you mind testing our drug? The reason he contacted us was because several years ago we engineered a different line of mice in my laboratory, a line of mice that, that makes too much PIA-1. They actually make too much human PAI-1. We thought that someday that would be an interesting reagent to potentially test drugs that block human PAI-1. If a drug company or someone ever came up with one. It turns out these PIA-1 over expressing mice that we engineered exhibit a few characteristics that also look like aging. They're bald. They have been since the day we first saw them.
Erin Spain: Never grew hair?
Dr. Douglas Vaughan: Well they've got sparse hair. We went through multiple generations of breeding them and observing them. You can always pick an animal that has too much PAI-1 out of the cage because they don't have their normal coat. They also developed a couple of other things that look like human aging, for example, they develop heart attacks as they age. They clot their coronary arteries. That's pretty unusual in a mouse. But again, that's a manifestation of aging in human beings. We have heart attacks. They also displayed or exhibited a remarkable deposition of protein in a variety of tissues called amyloid. Amyloid is an amyloidosis, is an aging related disorder. The deposition of amyloid is thought to be one of the drivers of Alzheimer's disease. We see amyloid in a variety of tissues, including the liver and the brain in these transgenic animals. So we published a description of these animals a few years ago. And then we had tried drugs that potentially could block PAI-1 that were developed by Pharma and nothing ever really did much in those animals. Toshio actually sent us some of the drug that they developed and we fed it to the mice for a couple months and suddenly the mice started growing hair. We said, well, I don't know exactly what this drug does or I don't know what it means, but it's certainly making these mice restore the health and the cycling of their hair follicles and it restored that part of the phenotype. So I said, wow, he's really got a drug that blocks human human PAI-1. So from then on we've been working together on this project and we've used it in a variety of different animal models. For example, if we feed that drug to the rapid aging mice, we can quadruple their lifespan. We can reduce the pathological changes that we see in multiple systems that look like aging. Toshio and his group have created a company in Tokyo and that company is moving it through the regulatory process in Japan. It's in phase two studies in human beings now. So, so it looks to be safe. It got through phase one in terms of administering it to healthy volunteers and they're testing it now. We hope to be able to start testing it here in selected populations in the not too distant future. We've filed an application for an IND with the FDA recently and we want to test it in human beings with disorders that might be influenced by PAI-1 like in diabetes or insulin resistance or fatty liver disease and potentially cardiovascular disease.
Erin Spain: Something that could help slow disease.
Dr. Douglas Vaughan: Exactly, and with the idea that maybe this might be an agent that might be useful someday in reducing the progression of aging like disorders broadly in human beings.
Erin Spain: And what's next for you? What are you coming out with in the future that we can look forward to?
New Speaker: Our studies in the Amish. Funding for that was renewed by the Heartland Blood Institute, We have another budget to go back and revisit that population and just to see what kind of changes have taken place over time. We took a snapshot over two days in a group from that community, but we want to go back and revisit the individuals that we've done all the measurements with before and expand the group that we studied as well. We're making plans and working on the logistics of doing that again relatively soon. We also think that there are other aspects of this that need to be tested. PAI-1 has been linked at least experimentally to Alzheimer's like pathology in mice. A couple of groups around the world, some here in the US, have used a form of this drug that we're interested in mouse models of Alzheimer's disease. It looks like it prevents or reduces the deposition of amyloid plaques and preserves memory and cognitive function in mice. So we're in the process now of putting together a grant to hopefully go back to the Amish population and ask if PAI-1 deficiency protect against cognitive decline. Does it protect against Alzheimer's disease? That's a very important question and perhaps this community could really impact on human health in an enormous way. I mean if what we already know of it, impacts on aging that that affects everybody, but talk about a devastating and challenging disorder. Alzheimer's disease falls in that category. If the mutation present in the Amish population provides some insight into how to prevent or treat Alzheimer's disease. Well, that would be very interesting. So we're on that now and we're actively involved in trying to get an IND to start doing limited testing for the effects of PAI-1 inhibition on metabolism and cardiovascular disease in human populations here in the US.
Erin Spain: We're very excited to see what comes next. I don't think there's going to be any shortage of interest in aging, as you said, as our population continues to age and grow. So thank you so much for coming today and sharing your research and your insights and we look forward to seeing what comes next out of that population in Indiana.
Dr. Douglas Vaughan: Well, thank you very much for having me. You know, with all this can't happen quick enough for us, but we're dedicated to it and hopefully we'll have some more interesting stories to tell you about in the not too distant future.
Erin Spain: Thank you. Dr Douglas Vaughan, who is the chair of the Department of Medicine here at Northwestern.
Dr. Douglas Vaughan: Thank you.
Erin Spain: A note for physicians who listen to this program, you can now claim continuing medical education credit just by listening to this podcast. Go to our website feinberg.northwestern.edu, and search for it CME for more details.