Are Lungs The Size Of A Tennis Court

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Thiennu Vu

Breathing is such an unconscious event – except when it isn't. Then and only and so practise we become a suffocating sense of how dependent we are on our efficient and expertly packed lungs to keep us both alive and energized.

UCSF's Thiennu Vu, Physician, PhD, needs no firsthand reminders. Indeed, she chose to report lung biology in large part because of the suffering of others she'd witnessed on hospital wards.

And because therapies are in short supply, Vu decided to do something nigh it in the laboratory. But first, she needed to uncover the developmental clues backside the wondrously simple way in which air and blood are brought together.

Certain, everyone knows we inhale oxygen and exhale carbon dioxide. But the system that allows this exchange of gases takes physical shape under rules nosotros take still to learn.

And what if we do? Well, the unfolded surface of our lungs would fill a lawn tennis court. That alone should brand the lungs worthy of our interest. But imagine the possibilities if we could somehow stimulate the adult stalk cells recently institute in the lung to repair damaged tissue? Recollect asthma, emphysema, lung cancer.

This is the stuff of heroic science – simply similar that practiced by the men and women in white coats who saved the earth in the Godzilla movies of Vu'due south youth. She was inspired then to become a scientist. She hopes others will at present follow her.

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Thiennu H. Vu, Faculty Contour

Podcast transcript

Jeff Miller: Hello, I'm Jeff Miller and welcome to Science Café, today I'm
with Thiennu Vu, an associate professor of medicine at UCSF, welcome Thiennu.

Thiennu Vu: Thanks very much.

Miller: Now, as anyone who regularly listens to Science café knows, I'thou peculiarly fond of MVPhDs, and then I need to enquire you lot right off the bat, how long did it take you to get both degrees?

Vu: It took me ix years.

Miller: ix years? That seems a picayune shorter than some I've heard.

Vu: I think information technology's almost the boilerplate. Some take longer, some accept shorter.

Miller: Is it true that MVPhDs take a special perspective on their world, primarily because they occupy 2, both the clinical side and the research side, practise you feel you have a piffling special perspective on problems?

Vu: I think that I do. I call back my medical grooming helps me to see scientific problems in a different style. I tend to retrieve of things that I can do that would help patients eventually, so I ask scientific questions not only for the intellectual curiosity, but also whether it is going to be skilful for patient care.

Miller: And that may non exist true for someone who is actually delving deep down into more basic scientific questions considering they never run across patients.

Vu: That could be true, but I as well know PhDs who ask questions of relevance to medical intendance. But that may not be on their mind every bit much every bit it is mine.

Miller: In your case. Nosotros're going to exist talking about your work with lungs and lung biology and lung development in just a second, but I'k curious to know, is there annihilation in your training forth the manner, was there some pivotal moment that turned you toward your current inquiry focus, maybe a patient problem, a problem of a relative, annihilation like that?

Vu: I think I got into pulmonary medicine first when I got into my clinical training, and I got interested in pulmonary medicine because I noticed the lack of really therapeutic treatment for a lot of the lung diseases, that was true when I was going through preparation and continues to be truthful now.

Miller: Permit's become a list of lung diseases so everyone is on the aforementioned folio.

Vu: The mutual diseases are asthma, COPD or emphysema, interstitial lung diseases, lung cancer, and some of the infectious diseases such as pneumonia.

Miller: Then when you lot've seen patients with lung diseases, did that trigger your interest?

Vu: Yes. Patients with lung diseases suffer a lot, it is a very uncomfortable and scary feeling when you cannot breathe. And because the lack of effective treatment, it really motivated me to attempt to practise research, to learn more than near lung diseases so that we can come up upwards with better handling for these patients.

And the other factor that motivated me to become into pulmonary medicine was patients in intensive intendance units. The patients are very ill, critically sick, and they're at moments of their lives when basically they cannot do anything only entrust themselves into the care of physicians, and the families as well are very concerned and worried about the patients. And a lot of the patients in critical care units are there because of lung issues likewise, so that also motivated me to become into pulmonary medicine.

Miller: And then how much time do you spend seeing patients and working in the lab at this point in your career?

Vu: Currently I spend about twenty per centum doing clinical medicine and the balance in the lab.

Miller: I know you came to the U.S. from Vietnam when you were 16, were there whatever members of your family who had a medical background, and what prompted you to even consider a career in medicine or science?

Vu: At that place'southward no ane in my family who was in medicine or scientific discipline, and actually when I was growing upwards I never thought about going into medicine – but I always wanted to be a scientist, fifty-fifty when I was a child.

Miller: And How did you know that equally a child, was in that location something in particular yous were interested in, were yous very curious nigh why things worked? How did that manifest itself?

Vu: This is actually a very funny reason, because when I was growing up – I don't know if y'all have seen or heard of a series of movies about Godzilla?

Miller: Sure, of class!

Vu: (laughter) They were very popular when I was growing up, my dad used to take united states of america to see Godzilla movies a lot, and in these movies, the heroes are always these scientist, in white coats trying to save the earth--

Miller: And yous wanted to exist one of those people-

Vu: I wanted to be ane of those people trying to save the world from Godzilla!

Miller: And now y'all're tackling lung illness. And then I think anybody understands on the nearly basic level that nosotros breathe in oxygen and exhale carbon dioxide, simply how do the lungs actually brand that happen?

Vu: I'm glad you asked that question considering the lungs are very circuitous but beautiful organs. I guess you know the part of the lung is to bring oxygen and blood together then that we can substitution gas. Oxygen into the blood and carbon dioxide waste matter products into the air. And it has to do that very efficiently then it has to movement air in and out of the lungs very efficient and quick-step, so when nosotros're sitting, talking, we're moving maybe iv or five liters of air per minute.

Miller: Just at present as nosotros're sitting and talking we're moving that much?

Vu: Yes. And you demand to move air in order to speak. When yous practise you increase that chapters as well, upward to maybe twenty or thirty liters per minute.

And then y'all have to bring the air into contact with the blood over a very large surface area then gas tin can diffuse between the two compartments very chop-chop too.

Miller: How large a surface expanse? I forget the actual measurements of the lung when you lay it out flat.

Vu: About the size of a lawn tennis court. Well-nigh 80 meters square is the full surface of the gas commutation area of the lungs. It has a series of conduits, which is the airways, to bring air in and out of the lungs very quickly. And and then it has this full surface expanse which is very large, but the problem is it has to fit all of that into the pocket-sized chest crenel equally well, and so how do yous fold up this large surface area with systems of conduits inside the chest cavity? That is a very complex trouble.

Miller: And this is a problem of development, how the organ actually develops, how information technology takes shape also as the structural integrity of it.

Vu: Exactly.

Miller: Is there annihilation special nearly the human lungs? Are they fundamentally different in some way?

Vu: It'due south not different from other mammalian lungs, then it's very similar to primate lungs or rogan lungs, but it'due south different from avian lungs for example, from the lungs of the birds.

Miller: Are human lungs among mammals the largest, the strongest, somewhere in between?

Vu: I call back it's not the largest, information technology's certainly non the smallest, it's somewhere in between.

Miller: The exchange that goes on at the alveoli level – is that something that is peculiarly complicated? I know information technology's obviously essential, and is it tied into some style in the style the lungs really develop?

Vu: The gas commutation?

Miller: Aye.

Vu: Information technology's unproblematic, you just have to bring air and blood together very closely separated by very sparse membrane, so that the gas tin lengthened freely very quickly. So the development of the lungs, how to make that happen is the complicated office.

Miller: At present are you studying at this bespeak in your research the actual development of the lung itself?

Vu: Yes, I have been studying lung evolution, especially the evolution of the gas substitution surface or the alveoli.

Miller: And what have you learned so far?

Vu: What I have focused on is how the development of the vasculature is regulated. How it develops and how it contributes to the development of the airways, And the reason I focus on that area is because in the lung, particularly because of the function of the lung, that it needs to bring air and blood close together, y'all really need to bring the blood vessels, very close together with the airways. Then there has to be cantankerous-talk. The two systems, when they develop, they have to talk to each other, and so that they develop at the same rate, the same time, in the same spatial human relationship.

Miller: In a normal state of affairs are the blood vessels very densely packed in the tissue or is it kind of a thin network.

Vu: It depends on each different organ, and so in each organ the vasculature has a very particular relationship with the tissue, so in some tissues information technology could exist very dense, in some tissues, more than sparse.

Miller: So now y'all're studying how this develops, conspicuously in doing so you're learning how things go wrong, then what does that tell you? Are these genetic influences? Is it the way the genes are non responding correctly in the form of development that underlines some of these lung problems – which I'chiliad sure if that's the instance, develop early in a person's life?

Vu: In that location are definitely genetic influences in the lung evolution, because if y'all modify the expression of several of the genes we've been studying, yous definitely see abnormalities in the development of the lungs. So what we've been focusing on is what regulates the vascular development, and we accept identified one of the genes that are critical for that, it is called vascular endothelial growth factor (VEGF), which is a very essential factor regulating claret vessel development in many different organs.

And that regulates how the vasculature develops. And if nosotros alter the expression of that gene, we inhibit the development of the vessels, and and then yous likewise modify or impair the development of the airways.

Miller: Is the mutation in that gene fairly common, and if so would information technology show up as something dramatic in a newborn, of would it be something more progressive.

Vu: Uh--

Miller: And before you respond, could defects in that system contribute to the development of asthma and other things?

Vu: The mutations of these genes have not been reported, I think because it is such an important factor for blood vessel evolution, that whatever mutations that cause alteration in its expression probably are not viable.

Miller: Then the fetus would not be viable.

Vu: Exactly. Only there could be alteration in expression, non because of mutation just because of environmental factors. For example in babies who are born very prematurely, and they have to be placed on supplemental oxygen or mechanical ventilation, and this could alter the expression of this growth cistron because they are exposed to higher level of oxygen prematurely.

When the fetus is in the womb the oxygen level is non every bit high every bit if y'all place them on supplemental oxygen.

Miller: And have there been studies of premature infants, as they grow upwardly, showing greater signs of lung problems?

Vu: Yes. And then these premature babies placed on supplemental oxygen or mechanical ventilation, sometimes practice not survive. And when they survive, they develop a illness nosotros call chronic lung disease of prematurity. And that causes them to have a lot of lung bug as a child and when they abound older as well.

Miller: Does the percentage of harm vary from person to person? Are nosotros talking 50% loss of function or greater, or what?

Vu: Information technology varies for individuals depending on how severe the impairment is when they are built-in.

Miller: And that would mean since the really tiny preemies would exist in the oxygen longer, if they survive, and then their lung impairment subsequently in life would be greater.

Vu: Exactly.

Miller: I know you are studying too, the possibility of using developed stem cells to somehow repair lung tissues, is that correct?

Vu: Yes. I'k interested in seeing whether at that place are resident or stem cells that reside in the lungs themselves, that can repair lungs after damage. And right at present, this is not our piece of work, simply other people take identified a population of what seem to exist stem cells in the lungs. And they reside at the very end of the airways, before the airways co-operative out into alveoli.

Miller: Was that a surprise to find stalk cells at that location?

Vu: In retrospect it's not surprising because if you think most the analogy of a tree, right now is cherry flower flavour, so when you look at a cherry tree in blossom, y'all can think of the airways every bit the tree and the branches of the tree, and the blossoms equally the alveoli. And when the blossoms are gone, you but have the braches of the tree left, just at that place's however something there at the tips of the branches, and then that the next flavor the leaves will come up out the blossoms will ascend over again.

So it could be like that with the lungs. At the end of the airways there'southward something there that tin be redeveloped into alveoli. So that makes me think that the location is not surprising. Simply whether these few cells that we take found that have stem cell properties at this location can really redevelop and reform the whole sets of alveoli again – you know like whatsoever buds are left at the tip of the tree tin grade the blossoms over again, is not clear.

Miller: But wouldn't these "buds" perhaps be damaged by the illness itself?

Vu: Possibly. Perchance. Right at present we actually accept not been able to place instances where the lungs actually regenerate post-obit disease or damage-

Miller: Is this something y'all're exploring though in your research?

Vu: Exactly. Yes.

Miller: Are you lot very early into to it? Are we many years away from having whatever kind of answer? Are there lots of people working on this or is this a specialty of yours?

Vu: There are a few people, a few groups working on this, I think there will exist more than, because I think nosotros're even so far from being able to induce the lungs to regenerate. Probably non in the almost hereafter.

Miller: I'thousand not going to put yous on the spot and say how many years before a cure

Vu: (laughter)

Miller: Now I'm going to ask you to put your clinical hat on for a second, we're near the end of our scientific discipline café interview for today… Is there annihilation people can practise, apart from non smoking, plain, to protect their lungs and health? Is in that location a way to increase capacity, obviously there'south do, what would exist some dos and don'ts?

Vu: I'k not certain if there's anything y'all tin really do to improve your lung wellness, besides trying not to cause damage to the lungs by smoking or past exposing your lungs to toxic chemicals or fumes or pollutions.

Miller: So if y'all paint at domicile, vesture a mask, these kinds of things?

Vu: Yes. Try to avoid breathing in fumes, smokes, chemicals that nay crusade damage to the lungs.

Miller: Just a question that occurred to me, are yous ever approached by groups on the exterior that may be complaining that they've been exposed to something in the air, and you're asked to offer your professional advice? Merely curious.

Vu: I haven't been, so far.

Miller: Cheers very much for joining me on Scientific discipline café – still stuck in my head is that epitome of my lungs splayed across a tennis court, I'll never think of them in quite the same mode. Thank yous for that and good luck in your research.

Vu: Give thanks y'all very much.