Gravity-Free: A Conversation with Cell Growth Space Scientist Millie Hughes-Fulford

By Jeff Miller

Photo of Millie Hughes-Fulford

Millie Hughes-Fulford

Outer space envelops us in a cold and bright mystery.

For some, like Millie Hughes-Fulford, PhD, director of the Laboratory of Cell Growth at the UCSF-affiliated San Francisco Veterans Affairs Medical Center, this mystery has lured them off the planet into a weightless world heavy with adventure.

But even the most ardent astronaut, or would-be astronaut, must accept the reality of human evolution. We are earthbound life forms, sculpted by the elemental force called gravity.

Hughes-Fulford, who was the first woman scientist to ride in the space shuttle in 1991, has long been a world leader in exploring what happens to our immune system and our bone cells when suddenly thrust into a gravity-free environment. It’s not a pretty picture. From bone loss to infections, humans in space seem fragile creatures. And indeed, extended space travel to distant planets – let alone the creation of a moon base – seems far too risky without “doing our homework,” as Hughes-Fulford continually insists.

Still, this native Texan remains optimistic about the value of both space travel and space science. Apart from humanity’s innate impulse for literally “looking over the next horizon” – an impulse she heartily endorses – Hughes-Fulford touts the spin-off effect. From osteoporosis to AIDS, what she has learned in space benefits disease researchers on the planet’s surface too.

That is in keeping with her world view that, in the end, everything is connected.

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Millie Hughes-Fulford



Podcast transcript

Miller: Hello I’m Jeff Miller, welcome to Science Café, today I’m here with Millie Hughes-Fulford, director of the Laboratory of Cell Growth, also known as the Hughes-Fulford Lab at the UCSF-affiliated Veterans Affairs Medical Center, welcome Millie.

Hughes-Fulford: It’s great to be here Jeff.

Miller: Millie’s also a former space shuttle astronaut on what turned out to be the ill-fated Columbia, she studies, among other things, the effects of weightlessness on the human immune system. So my first question is why that, and not something else?

Hughes-Fulford: Well, as a child I was a big space buff, I love science fiction, and at 5-years-old I thought I wanted to be a space cadet or an astronaut--they didn’t exist back then by the way--and I saw all of the Apollo astronauts, Mercury astronauts, and it wasn’t until I was older that I realized none of them were women (laughter)-

Miller: True--they seem to be always the exotic planetary princesses or something, but not astronauts

Hughes-Fulford: Not astronauts, so, long story made short, I became a scientist, and a chance came that I could put my hat in the ring to be an astronaut and I was lucky enough to be chosen, and I got very interested in looking at the diseases associated with space flight, and they’re mainly in the areas of osteoporosis and Immunosuppression.

So that’s how I got started on my road to looking at the body systems that seem to depend on gravity for normal function.

Miller: You were selected for that original space mission as a space scientist-

Hughes-Fulford: As a space scientist.

Miller: Was that the first time that scientists studying these types of things have been included in missions?

Hughes-Fulford: We actually had on Space Lab 1, Owen Garriott and a few European scientists fly. I was the first woman scientist to fly on the shuttle.

Miller: And what year was that, so we can get our chronology correct?

Hughes-Fulford: OK, it was on STS-40, it was 1991.

Miller: You’ve mentioned Immunosuppression and osteoporosis, so let’s start with the bone part. I know you’ve done a lot of experiments – can you kind of summarize the types of experiments you’ve run in space, and then what you’ve learned?

Hughes-Fulford: The first one was on STS-56, where we smuggled aboard on a commercial flight, some bone cells to look at what happens to bone cells in space flight, and what we found was that they did not grow as quickly and that their internal skeleton called the saddle skeleton didn’t form properly in space flight.

Miller: Was that a surprise?

Hughes-Fulford: That was a surprise. It was the first time anyone showed that the saddle skeleton was abnormal in space flight. And later other people found that to be true in the immune cells.

So anyway, after STS-56 we were able to fly bone experiments on three flights, and what we found was that the bone cells are not making the normal bone growth factors they normally make – those are down – we had on board, a 1 G centrifuge so the cells that were in a gravity field made those growth factors normally, so it was a matter of gravity.

We have found that in some cases we can add back those factors and get the cells to grow normally, so we kind of have a handle on -

Miller: You can add back those factors while in space, or-

Hughes-Fulford: -in simulations. So basically the bone cells need gravity to perform properly, and in some cases you can do a lot of resistance exercise and cut down the bone loss. On Apollo, they lost in two weeks an average of 2 percent, on Skylab in 30 days one guy lost, I think, seven and a half percent of his bone, and then on space station Mir, we had people who were up for six months, and one individual lost 24 percent of his bone and he did not recover it.

Miller: Even back on earth-

Hughes-Fulford: Even back on earth it did not recover. Yet we have other people that did not lose any bone, so it must be something in the differences between people; it must be the genetics involved, that the genotypes, the people were different; so we really need to do some homework on who is losing the bone, who’s not losing the bone, and the counter measures that we need to do the keep the bones healthy, especially on the moon where we only have one-sixth the gravity, and of course a trip to Mars.

Miller: We haven’t yet talked about the immune system, so let’s talk about those experiments and what you’ve learned…

Hughes-Fulford: On Apollo, 15 of the 29 astronauts had some type of infection either during the flight or immediately upon return. That’s a pretty big number for healthy people. There are also studies done on white blood cells and it was found that they were not activating properly, specifically the T-cell.

Dr. Augusto Colgaly was the first to show that the isolated white blood cell did not proliferate when stimulated in the micro-gravity environment, thus showing that gravity was required for normal T-cell activation. Now we’ve done some studies since that time with Augusto and have found it’s probably one of the IO2 receptors that’s not being turned on.

We have another experiment coming up next September where we’re actually going to be able to look at the early signaling and find out why the T-cell is not being activated.

Miller: And this experiment is going to take place…

Hughes-Fulford: On ISS, International Space Station, I think this time it’s going to go up on shuttle, that’s what we hear…

Miller: On a U.S. Shuttle-

Hughes-Fulford: On a U.S. Shuttle. All of the other experiments have had to go on European space agency projects, that meant we had to go to Russia and to Kazakhstan to do our work.

Miller: To the former Soviet space site ground zero-

Hughes-Fulford: That’s right, the Russians have I think a 50 year lease with the Kazakhstans to be able to launch, but for right now it’s a long way to get to Kazakhstan to do your work.

Miller: Have you launched with the European space agency these experiments once or twice?

Hughes-Fulford: Twice. We just got back from the second time in October, where we put an experiment with monocytes up there. There are two cells that are affected by space: one are the T-cells, and the other are the monocytes. In general, what the monocyte does is it is the guardian of the body, it matures into a cell called the macrophage, which means big eater, and what happens is the macrophage eats bacteria. And so, when you get an infection, the macrophage is eating it. Literally, it recognizes it and eats it.

But what happens in space flight, we’ve seen in returning astronauts, that the monocyte itself, there’s fewer of them, and that fewer of those are being turned into macrophages, so they’re not maturing properly. So the experiment that we did in October was, we took then on a site, put it in space, then we activated it to turn into a macrophage, and so we’re looking at the gene expression of that.

Miller: So is it the absence of gravity that’s really at the root of all this?

Hughes-Fulford: We believe it to be the absence of gravity, on the European flights we’re able to have a sample that’s in a 1G centrifuge, and so we actually can know what happens in a 1 gravity situation versus space flight. Or macrogravity.

Miller: So we’re revealing I guess, as products of earth-bound evolution, the impact of gravity on how we’ve-

Hughes-Fulford: Evolved, yes.

Miller: So that’s what’s happening here. You mentioned the moon earlier, so I know a moon base is planned, and I know you’ve been somewhat outspoken about the need to take certain measures, so tell me about that.

Hughes-Fulford: Well since we have 15 of the 29 Apollo astronauts that became ill during the Apollo program, we know that there’s a possibility that we’ll see that same Immunosuppression on a moon base. And so my concern is we haven’t really done all our homework in finding out why the T-cells are not being activated, and of course on the moon there’s a lot of moon dust, and during Apollo they found that the moon dust would get in the air, it got all over them.

So we would have to control the dust, for one thing you don’t want the dust in the air and people breathing it in, that might have bacteria attached to it, the other thing is the moon dust is very sharp, actually on some of the suits that came back from the Apollo astronauts, they were worn, because it was more like an abrasive, and anyplace they would have movement it would just saw into the fabric.

And so, you don’t want people breathing that in.

Miller: So what measures are being taken, as plans take shape for this moon base.

Hughes-Fulford: Well hopefully by now they’re putting in a lot of filters and a lot of fans to keep the dust down. I haven’t seen the plans lately, in the beginning I know they weren’t really considering how to maintain it but I think they are beginning to think about it now.

Miller: And with the immunosuppression the risk then is if someone gets sick then everybody gets sick-

Hughes-Fulford: It’s in the air, right-

Miller: -and that could devastate the whole group of people who are studying and living and working there.

Hughes-Fulford: I think that we just need to do our homework, find out A) how much gravity do you need for your T-cell to normally activate? I don’t know. We haven’t done the work. How do you keep the moon dust off of things because it has some static electrical properties that tends to cling to people. There’s a picture of one of the Apollo astronauts that looks like he’s got black on his face – it’s moon dust. So I think it’s real important we start looking at these things and do our homework before we get there.

Miller: I could envision what an exercise space on a moon base might look like as a gravity counter-measure, but when we talk about a longer space flight, like to the planet Mars, how does that work?

Hughes-Fulford: I think all of us have seen the movies with the spacecrafts with rotating centrifuges inside, like 2001, I think that’s the best way to do it -- create an artificial gravity. So far, I haven’t seen any space vehicles being designed that had that built into them.

Miller: For reasons of cost, or for other reasons?

Hughes-Fulford: Oh, it takes a lot of energy, if you have a centrifuge going one direction – it’s kind of like a top -- it’ll be going in another direction –you’re causing a force to get off orbit so you need two of them going in opposite directions to stay in your flight path. So that cost money to run, but again the question is, do you need it 24 hours, or do you just need an hour of it a day to keep everything normal-

Miller: And we don’t have the answers to that question yet –

Hughes-Fulford: I don’t know. No one knows. So I think doing a little bit of homework might save us a lot of money.

Miller: Some have said on maybe the longer space flights, that we use robots instead of human beings.

Hughes-Fulford: Oh I’m a big fan of the robotics guys, JPL, big fan. We need robotics. We need to go. We need to find more about Mars, do we have water on Mars, it’s going to make it a lot easier to live on Mars. So I think we really need robotics to do our homework with.

And then I think we need to go into space, but I think we need better propulsion, we’re still using the same old-fashioned propulsion they were using in World War II-

Miller: The technology’s not improved at all since then?

Hughes-Fulford: I don’t think it’s changed a bit.

Miller: We don’t have any bright young engineering students studying propulsion?

Hughes-Fulford: Well you would have to have a program to help support them. People have to eat, and they have to have a place to sleep. You can have great ideas but you still have to live. And unless we have programs to promote new thoughts, and to take us into new areas, it’s not going to happen.

Miller: And you’re saying these programs don’t exist?

Hughes-Fulford: I haven’t seen a lot of them – I would like to see engineering schools get grants to do forward thinking, and then pick the best ideas and then fund them. I do know there is a plasma drive being worked on in Costa Rica --

Miller: In Costa Rica by whom?

Hughes-Fulford: I think it’s Chang Diaz, a former astronaut, who is working on it. And I think they’re making some progress on it and a plasma drive would only take about a month to get to Mars instead of nine months, so that would reduce the amount of radiation exposure, reduce the amount of damage from not being in a gravity field, it’d be much better.

Miller: Is it realistic for us to assume that we’re going to inhabit other planets? That’s a little out of your field I realize but you’ve been an astronaut so let’s speculate.

Hughes-Fulford: I believe that we, as a people, as a planet, will explore. It’s in the nature of mankind. I think it would take the entire population of the planet to really start thinking about going to another planet, or going to another galaxy, and I think it would take a lot more technology and development than what we have right now.

But yes, I don’t see any reason that by 2,300, we would be doing that. There’s probably a warp drive engineer out there, a young kid, or one yet to be born… Yes, absolutely.

Miller: Fair enough. Early in the space program, on one of its enduring facets, was this spin-off s into consumer culture and other things. Since you’re in the field of health, I’m wondering, these things you’re learning, are their going to be more benefits for more earth-bound needs?

Hughes-Fulford: I think so. I think if you look at the spin-offs we had already from NASA, remote monitoring and ICUs was a shoot off of what NASA did, Velcro of course, as we all know. A lot of the remote technology in medicine was originally done by NASA, and it was spun-off.

What we think we’re going to get back from basic studies of the immune system is that we’re able to turn off certain signal pathways in microgravity that we can’t do in other situations. And so we’re learning more about how immune cells work, and once you know what part of the system’s not turning on and what that does, then you can target that system to turn on.

So I think we can do a lot with the knowledge that we’re getting back from space flight.

Miller: So that might be a benefit to those with immunosuppressive diseases, perhaps?

Hughes-Fulford: Absolutely.

Miller: And how about osteoporosis?

Hughes-Fulford: Again, right now we don’t know the origin of osteoporosis in space flight, we know that it’s probably due to the lack of gravity. There have been some cases where people on Mir were exercising for four hours at a time, and they still lost bone. It might be in the genetics of the person themselves – but we do know that gravity is involved and we do know that not having gravity means that we’re going to have to do more resistance exercise and so forth, but to really know how to turn on new osteoblast growth, I think that’s the next step in the treatment of osteoporosis.

We need an anabolic, or a constructive treatment, so we can rebuild bone, rather than just keeping it from being destroyed.

Miller: I know that in addition to the things we’ve discussed you have some other research interests as well and you recently got a grant for stem cells?

Hughes-Fulford: Yes, we are looking at the possibility of growing stem cells in a more rapid manner and turning them into new bone cells for osteoblast, and then looking at mineralizing them. And it’s being supported by the DOD, and we just heard that we most likely have a VA grant coming in to look at a similar project, using stems cells and repair of bone.

Miller: And you have done earlier work in prostate cancer- can you tell us about that?

Hughes-Fulford: In prostate cancer I was interested in how the different fatty acids affected prostate cancer. As you know in this country we have a lot of Omega 6 fatty acids that we intake, and we’re not eating as many Omega 3’s, that’s fish, oils from nuts, we don’t graze our cattle anymore, they’re corn-fed so they have a lot of Omega 6 in them, and looking at the ratios, we can manipulate in the laboratory the ratio of Omega 6 to Omega 3, and control the growth of tumors in tissue culture.

Miller: So more Omega 3, much less Omega 6.

Hughes-Fulford: Absolutely. Early man had 1 to 1.

Miller: And what’s the ratio today, do you suppose?

Hughes-Fulford: About 25 to 1.

Miller: 25 Omega 6, to 1 Omega 3. I’d say that’s disproportionate there-

Hughes-Fulford: It is. It’s very important we keep looking at this. We’re writing grants – it’s not like I’m not writing grants to do the prostate cancer work, it’s just that there’s not as much funding right now. I’m lucky in that I have several grants that will keep me alive, but the funding at the NIH is way down; NASA funding is down by about 90 percent in the life sciences, so we’re in a period of time when the government is not supporting science like it did.

Miller: What is the connection, we have prostate cancer, immune systems issues, bone growth, is there some connection to all these things?

Hughes-Fulford: Probably an inability to focus --- no, that’s not true (laughter) – I look at systems, and what makes systems work. And if I’m looking at an immune cell or a bone cell or a cancer cell, I’m looking at what makes it grow.

The cancer cell, I don’t want it to grow. The bone cell, I want it to grow. The immune cell, I want it to grow, but it’s the same system. So you can think of me as a systems engineer. I want to find out what makes things work.

Miller: While I have you here I want to talk a little bit about women in science. You are yourself a very successful woman scientist and I wonder if those that you’ve encountered in your lab recently, complain about some of the same things you might have encountered in your career, some discrimination, or has it all faded now?

Hughes-Fulford: Well we are in California, and California is a fairly liberal place to be a woman scientist. I haven’t seen a lot of blatant discrimination at all; I think it’s a fairly level playing field right now, at least here.

Miller: How about earlier in your career, was there a nurturing father or some relative who helped to guide you along the scientific pathway?

Hughes-Fulford: It was my father. Absolutely. And of all the female astronauts I’ve ever talked to, it was their father that was encouraging to them. So to the fathers that are listening to this, you create your daughters’ destiny.

Miller: Were there some particular words that you recall?

Hughes-Fulford: He was always there, I remember one day in third grade I was working on some word problems in math, was having trouble, he came in (we owned a supermarket and he was on his feet twelve hours a day, and now I know how tired he had to be when he walked in, back then, you didn’t know) and he said what’s wrong?

I said I was having trouble, he said come and sit on my knee and we’ll work through it together. That’s what I remember.

Miller: That’s a very wonderful memory, thank you for sharing it, and thank you for joining me today on Science Café, I wish you great luck in future research efforts and hope to be reading about new and exciting developments.

Hughes-Fulford: Thank you Jeff, and thanks for inviting me.