Science Friday - After A Park Fire, Milkweed Bloomed | The ‘Creepy’ Procedure That Taps Into Young Blood

Episode Date: October 31, 2024

Great news for the nearly-extinct monarch butterflies, which will pass through the area as they migrate back to Mexico. Also, to find out how blood affects aging, scientists can surgically connect two animals and let blood circulate between them.After California’s Park Fire, A Second Bloom of MilkweedDon Hankins examines a bright yellow-green patch in the meadow. The land all around is charred by fire. But here, there’s a sort of miracle at work. Native milkweed has sprung up and bloomed for the second time this year. This is not something these plants, Asclepias eriocarpa, also known as Indian milkweed, are known to do.They bloomed in late spring and early summer and had already done so this year when the Park Fire roared through. But the fire seemed to happen at just the right time to coax a second flowering, one that is likely to line up with the return migration of the monarch butterflies south to overwinter in Mexico. Monarchs rely on these flowers to complete their life cycle. For researcher Don Hankins, this is a surprise delight.“We may be coming back into some knowledge here that hasn’t been practiced in a long time,” said Don Hankins, a professor at Chico State, who teaches classes in geography with a focus on fire. He is also a California Plains Miwok traditional cultural practitioner.Read the rest at sciencefriday.com.Inside The ‘Creepy’ Procedure That Taps Into Young BloodWhile fictional vampires suck the blood of the young to live forever, some researchers have found that certain elements in young blood actually can improve the health of the old. This is possible through a spooky procedure called parabiosis, in which the circulatory systems of two animals are joined, letting the blood flow from one into the other.By connecting old mice and young mice through parabiosis, researchers have observed how different molecules in the blood impact symptoms of aging. While some outcomes have excited experts, enthusiastic biohackers attempting to defy their own aging might have jumped the gun. There’s a long way to go before we understand how elements of young blood might be harnessed to treat aging humans.Emma Gometz, SciFri’s digital producer of engagement, talks to Dr. Tony Wyss-Coray, a neurology professor at Stanford University who has used parabiosis (which he once described as “creepy”) to help reveal how components of our blood affect our cognition as we age. They discuss parabiosis, vampires, and how far the field has to go before humans can benefit.Transcripts for each segment will be available after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

Vampires aren't the only ones interested in young blood. Researchers are learning how it could affect aging and the brain. We can transfer young blood into old mice, and their memory function becomes better and more like a young animal. It's Friday, October 31st. Happy Halloween and Happy Science Friday. I'm Cyfry producer Dee Petersmith. We have a lot of new vampire movies and TV coming out, like the new adaptation of Stephen King's Salem's Lot and the Nospheratu movie coming out in December. And we found out about a research procedure that shares an eerie similarity with our favorite fictional bloodsuckers. That's coming up. But first, here's guest host Sophie Bushwick discussing how a recent Californian fire could help out the struggling monarch butterfly population.

And now it's time to check in on the state of science. This is KERNO. St. Louis Public Radio News. Iowa Public Radio News. Local science stories of national significance. California's park fire scorched 430,000 acres of land this summer. It was the fourth largest fire in the state's history. But there's been an unexpected success story that has sprouted from the ashes of this charred landscape, a boon for monarch butterflies.

Joining me to talk about this story is my guest, Danielle Vinton, science reporter for KQED Public Radio in Sonoma County, California. Welcome to Science Friday. Thank you for having me. You went out with some experts to check out the post-fire landscape. What did you find? I found the remains of a fire that had burned very intensively over an enormous area. I'm really interested in how prescribed fire can be used to make landscapes more healthy and protect against the worst, most destructive fires. So I visited areas that had been prepared for fire with prescribed burns, and I saw lots of places where these burns

had helped slow and calm the fire, saving houses, saving the older, bigger trees, and a few places where the fire burned hot and out of control anyway. But in looking at these different examples, I came across something I had never seen before, something almost no one alive today has. I was checking out the Big Chico Creek Ecological Reserve. I was with Don Hankins. He's a professor at Chico State. He teaches classes in geography with a focus on fire. He's also a native person. He's a California Plains Miwok traditional cultural practitioner. And he showed me a bright yellow green patch in a meadow. The land all around was charred.

But here, native milkweed plants had sprouted back up just weeks after the fire. Their flowering period in this location is usually the later part of spring, early part of summer. So they would have already set seed at the time the fire had come through. And this year we're getting another round of flowers. and maybe we'll get another set of seeds. And I'm thinking the timing of when they flower will probably coincide about the time that monarchs are making their migration back south. And this is something they're not known to do, flower and set seed more than once a year.

And what's the relationship between this milkweed and monarch butterflies? For monarchs, milkweed is breeding habitat. The adults use the flower for nectar. And the leaves are the only thing they're larvae, the caterpillars, will eat. And the milkweed provides protection to the caterpillar. Milkweed holds toxins called cardenolites. Monarchs are fine with these, but most other animals aren't. It'll make them vomit. The caterpillars store this poison in their body, and it gives them their bright coloring, white, yellow, black stripes as larva and the black and orange that's so striking as adult

butterflies. This coloring is a warning to birds. Don't eat me. I taste bad, and I'll make you sick. And in your reporting, you learned that what's happening this year with milkweed ties in with some indigenous knowledge from the past. What did you learn about that? Native tribes of Central California tended milkweed with fire and used the plant's fibers for garments known as feather belts, weaving fibers together with feathers from important bird species into these velvet-like textiles decorated with geometric patterns. While milkweed and such birds were once abundant, today they're comparatively rare. And Hankins believes by seeing this were coming back into some indigenous knowledge that hasn't been practiced in a long time. And monarch butterflies are near the brink of extinction.

Could this knowledge help us bring their population back? It could be helpful. It's going to take more than this, of course. The loss of milkweed habitat due to pesticides has been a major driver. in the decline of monarch populations. For the western population, those west of the Rockies, they've also been hit by the loss of overwintering habitat. So there's lots of work to do. But I checked with Don Hankins to see if monarchs had been seen on this new crop of milkweed plants, and he said that better than that, larva had been spotted on them. So that's really neat.

I also want to mention all of us with gardens can help monarchs. One way is by planting native milkweed, but when doing this, watch out. A lot of people have planted tropical milkweed plants. They're brightly colored. They bloom longer. But they're not as helpful for butterflies. It messes with the signals of when it's time to migrate and increases the spread of parasitic diseases. If you do have tropical milkweed, you can try cutting it back in the fall so that it more closely mimics native species blooming patterns and plant native varieties when you can.

That's all the time we have for now. I'd like to thank my guest, Danielle Vinton, science reporter for KQED Public Radio in Sonoma County, California. Thank you for joining us. Happy to be here. After the break, we'll dive into paribiosis, a creepy procedure that's helping scientists learn more about Alzheimer's. It's officially Hala Weekend. I'll be celebrating with a spooky movie. And I noticed we have quite a few new vampire offerings coming out.

There's the new adaptation of Stephen King's Salem's Lot, the Nosferatu movie coming out in December, and my personal favorite, the final season of what we do in the shadows. And just as vampires suck the blood of the young to live forever, some researchers have found that certain elements in a young person's blood can actually improve the health of the old. This is possible through a spooky procedure called paribiosis, where the circulatory systems of two animals are joined, letting the blood from one flow into the other. That procedure has found its way into movies and TV as well, like in this clip from HBO's Silicon Valley. Is Bryce your assistant? No, of course not. It's my transfusion associate.

Which is? Are you really not familiar with paribiosis? I can't say that I am. Well, the science is actually pretty fascinating. Emma Gomez, Cy Fry's digital producer of engagement, who writes our science goes to the movie's newsletter, sat down with a neurologist who's used this technique to research aging and the brain. Here to tell us more is Dr. Tony Weiss-Carray, a professor of neurology at Stanford University. Welcome to Science Friday. Thank you for having me. So you've said that talking about paribiosis is a bit creepy before, and it reminds some people of vampires. Why is that? That's right. Well, you know, just the idea that

two animals would be sutured together at their flank. Sounds a bit spooky. And even though it's 100 years old, I think it's still something that not everybody would feel comfortable about. And could you just tell us what is paribiosis and who came up with it? Yeah, so this is a technique that was invented over 100 years ago by Paul Baer in France. And the initial idea was to test whether animals could share their tissues. And the model has really had a big impact in transplantation of tissues that we now take for granted. It also led to the discovery of sex hormone or an obesity hormone. And more recently, it has been used to study aging. And so why is there a need to use this procedure in research at all? Like what health conditions does this benefit? So it's not directly a

health benefit, but a researcher have wondered whether something in the blood might be associated with age. So in other words, is the blood from a young animal, for example, or a young person different from that of an old one? And indeed, we see that the composition at a molecular level is very different between young and old people, between young and old mice. And so people then in the aging field wondered, what if we would... expose an old organism, specifically old stem cells, to a young circulation, to factors from the young blood. The way I got into it is really from my interest in understanding Alzheimer's disease, and one of the key drivers of this disease is age. And we noticed that the composition of the blood

changes dramatically with age. And so when my colleague Tom Randall made these discoveries that blood from young animals is beneficial for muscle regeneration. We wondered, of course, could the same be true for the brain? And he had indeed some hints that this might work. So that's really how we got into it and then wanted to understand better what are the factors and is old blood detrimental for young ones and so forth. So you mentioned these factors in young blood, like elements in the blood of young people. Can you explain what they are and how they affect our health as we age?

Yes, so we haven't really discovered enough about what exactly these factors are. My lab and others have focused on proteins specifically, and we see many proteins change in concentration from young to old. And some of them seem to have beneficial effects on the body. They maintain tissues, they maintain stem cells. And then we also find accumulation of factors. that seem to be detrimental that accumulate with ages. Some of them involved in inflammation. Right.

So just so I'm understanding this, you find this out by circulating the blood of a young animal into an old animal, and then you can see how that affects the older animal. That's correct. So technically, you actually only suture the animals together at their flank, at their skin, and then blood vessels grow into this wound. and so you have a connection between the two circulatory systems. It's a very slow exchange.

But we showed later on, actually, that you can simply collect the blood of a young animal and then infuse it into the old one and reproduce some of the same effects. So you specifically study how these circulating factors can affect our brains and our cognitive functioning. So what are you researching right now related to that? So we're really interested in how the brain is.

ages and working together with Tom Randow, we asked whether these effects that he saw on the muscle would also apply to the brain. We identified some factors that are detrimental that accumulate with aging and we can block them and at least in mice show that this benefits the old mouse. And we also, as I mentioned earlier, we can transfer young blood into old mice and the mice show improvements at molecular levels, at the cellular level, and then most importantly, their memory function becomes better and more like a young animal. Oh, okay. Can you tell me a little more specifically what you mean by improvements? Like, what about it changes?

Yeah, so as people get older, and especially if they get cognitive impairment and Alzheimer's disease, one of the characteristics is that they lose spatial orientation, so they may get lost in their neighborhood taking a walk. And interestingly, we see the same in mice. So you can imagine a mouse must be able to find, you know, where its nest is or where, you know, it was hiding some food or things like that. And as the mice get older, they have similar deficits. And we can actually quantify them.

We can measure them. There's a number of different memory tests that have been developed for mice. And as they get older, they get impaired in these tests. And what we've shown is that, If you give an old mouse infusions of young blood, then they do better again in these tests and show improvements in function. Wow, that does kind of remind me of a vampire, I got to say. So does this go the other way? Like, do, like, does circulating old blood from older mice into young mice do anything? When you create paribiosis, does the blood flow both ways or does it only go from one to the other? Yeah, that's a fantastic question. So indeed, what we see is that the old blood is actually detrimental for a young organism, and it induces impairments and mimics aging to some extent. So we have now tools

that allow us to measure molecular changes that are associated with aging, and we can show that old blood can accelerate these aging changes at a molecular level and also at a functional level. It can cause inflammation. And then, as I said earlier, the young blood can reverse some of these effects in older animals. So it really goes both ways. So paribiosis is done mainly on mice, like you said, but how close are we to using the results of this research to develop treatments for humans? And what would that even look like? So one approach would be to, try and use blood donations from young individuals and give them to people with Alzheimer's disease, for example. And indeed, that's what we did in studies together with industry could show that,

at least in early stage trials, that this is well tolerated and might be beneficial. This is something, as you know, in the hospital, you know, blood donations are used all the time, whether it's for, if you lose blood in surgeries, but sometimes also exchanging blood if people have autoimmune diseases. And then people who are immunodeficient, they get parts of fractions that are isolated from blood donations. So it's something that is very frequently used already in the clinic, and it's possible that this could be adapted. The other direction is, of course, to try to find what are the individual components, what are the individual factors, and then produce them synthetically as we do for other drugs and apply them for the treatment of age-related diseases. Wow. Parabiosis and research on young

blood has popped up a lot in the media, like the Silicon Valley clip we played earlier, or even among some enthusiastic biohackers who get blood transfusions from the young. Does this actually work for humans? We don't know yet. There are studies underway. There's a study in Norway that is testing this. And we did studies earlier in just small numbers of individuals to test whether young blood, blood from young people could be beneficial for patients with Alzheimer's or Parkinson's disease. But the results are still out.

So we really need large clinical trials that are controlled with placebo so that we can figure out, Does this really work? So it's a don't try it at home situation right now, right? Exactly. Don't do it in your kitchen. Okay. And where do you see this field going in the future? I think one of the key directions has to be to figure out what are the components.

We know now it's not going to be one factor that can do it all. We know from studies, very broad studies where we interrogate every cell in the body of a mouse. and see how does it respond to old or young blood, that different cells respond in different ways to factors, suggesting that you would probably need more than one factor if you want to have very broad benefits, almost like a cocktail. The alternative is to find factors that are beneficial for one tissue. So if we could find a factor that is particularly beneficial for the brain,

that might still lead to the development of a drug based on these discoveries. You know, this has been a really enlightening conversation, but I definitely do think it's still a bit spooky. Do you have a favorite vampire movie or anything? Are you a spooky guy? I don't know what that means. I don't have a favorite vampire movie, but yeah, it certainly fits the season. Definitely. Well, thank you so much for your time.

This was a lot of fun. That's great. Thank you. Dr. Weiss-Carray, Professor of Neurology at Stanford University. If you'd like to read more about paribiosis and check out how it connects to a vampire movie that just came out, you can go to Science Friday.com slash vampire. I'm Emma Gomez. And that's it for today's episode. A lot of folks help make the show happen, including... Jordan Smudjik.

Rasha Ridi. Charles Bergquist. Shoshana Buxbaum. Tomorrow, we'll dive into the top news in science this week. I'm Cyfry producer Dee Petersmith. Thanks for listening.