Every high school biology student knows that the mitochondrion is “the powerhouse of the cell.” But what does that really mean?
In scientific terms, the mitochondria (the plural form) perform cellular respiration. This means that the mitochondria break down the nutrients in the cell and turn those nutrients into energy. In other words, the food that we eat and the air that we breathe would be essentially useless to us – and to most living things — without the mitochondria. The mitochondria use these nutrients to create the energy that allows our cells to grow, divide, and function.
So it is clear that mitochondria are essential to life. But why is it important to study them, and how does Auburn University’s MitoMobile further our ability to do that?
To answer these questions, we sat down with two prominent muscle physiology researchers whose work focuses on lactate metabolism and the mitochondria in health and disease: L. Bruce Gladden and Andreas Kavazis, both professors in the Auburn University School of Kinesiology. They answered questions that might help others realize why this work is important, and the unique role that Auburn University’s MitoMobile – a mobile mitochondria laboratory – can play in the large realms of human and animal health; evolutionary biology processes such as climate change and ecological disasters; and outreach and education.
Q: Give us the big picture. Why is it important to study mitochondria?
GLADDEN: Well, at the most fundamental level, life depends on energy. All of the billions and billions of random molecules that make up organisms — including people and their pets and the entire animal kingdom – require energy for cellular respiration to take place. And this happens because of – and only because of – the mitochondria. We hear that the mitochondria are the powerhouses of the cell. Well, it really is just that. The mitochondria do the work – the cellular respiration – that turns nutrients into the energy we need to live and move and have our being. So that is the big picture.
But on a practical level, we know that mitochondria are closely related to issues of disease in humans and animals. There is near-irrefutable evidence now that the mitochondria play key roles in cancer, diabetes, and obesity, which far and away have the most lethal impact on the lives and health of Americans. And from a strictly performance level, which is a particular research interest of mine, the mitochondria are essential to our ability to move and function. This impacts every aspect of health and performance, whether that is an Auburn University football player or a city firefighter, or a show dog, a greyhound, or a racehorse.
The great August Krogh, who in 1912 won the Nobel Prize in Physiology or Medicine, noted that for many problems, there will be an animal or a few animals on which it can be most conveniently studied. So our ability to study the mitochondria, whether in humans or selected animals, can have a profound impact on our health and wellness. You simply cannot treat a disease if you do not understand it.
Q: So how does the MitoMobile, Auburn’s mobile mitochondria lab, relate to some essential research questions?
KAVAZIS: The MitoMobile allows us to work in the areas of health research, biological evolution, and education and outreach.
To measure cellular function, or mitochondria, you must have living tissue. From the time you collect these samples, you have at most two hours to get any useful information. And these samples cannot be frozen. You must be right there where the animals are. The MitoMobile allows us to go anywhere to find that tissue, rather than being isolated in a lab on campus using, let’s say, mice. We could also use the MitoMobile to study mitochondria from human biopsies in specific communities, for example. The MitoMobile takes us where the action is.
On our first-ever trip, we drove from Auburn to Moscow, Idaho, where we did experiments on dairy lactation. These on-site experiments could have a number of far-reaching research implications. These implications might include not only improved agricultural outcomes that positively impact farm economies, but might also provide insight into human lactation and the long-term impacts of breastfeeding, which we might use to combat obesity and diabetes.
Q: What’s this about mitochondria and obesity?
GLADDEN: As I said earlier, you cannot treat a disease if you do not understand how it works. In the long run, basic science is about improving the human condition. So how does that relate to fat metabolism in humans?
We know this without a doubt: obese people do not metabolize fat very well. Fit, lean people do. We know that birds can fly days and days using only fat as a fuel. Think about a hummingbird and the energy it expends doing what it does. It is an amazing example of mitochondrial machinery. Now think about mammals – dogs, horses, humans. We cannot do what a bird does. Why is that? We know that fat is metabolized only in the mitochondria. So if we can understand how mitochondria work in the different species of the animal kingdom, that may very well lead us to learn how to combat obesity, and positively impact the occurrence of diabetes along the way, thus greatly improving the human condition and eliminating billions and billions of dollars wasted in needless medical costs.
Q: Andreas, you mentioned evolutionary biology and education as ways the MitoMobile can impact our lives, along with basic research into human health. What are some examples of that?
KAVAZIS: Well, there are countless examples. Let’s take one example in the area of pollution and ecology. Virginia’s Shenandoah Valley is contaminated with mercury, a result of decades of coal mining and runoff into the rivers and streams in the area. Mercury, as we all know, has a detrimental impact on growth and development as well as on cognitive function. With the MitoMobile, we can go into the polluted areas of the Valley and collect and study live tissue samples. We can then drive just outside of these contaminated places and take parallel samples and compare them. But to do that we must be on site. There is only one way to get these samples into a lab, and that is to be there. The MitoMobile allows us to do that.
And there are countless ways to respond to environmental crises. One would be to study marine species in the midst of an event like the Deepwater Horizon oil spill in the Gulf of Mexico from a few years back. How did those animals respond to that crisis? Another might be to assess the impact of animals displaced by the wildfires now sweeping through California’s Sonoma County.
Q: What about education?
KAVAZIS: Again, the ways we can impact communities and students with the MitoMobile are almost endless. On our recent trip to Idaho, much of the work was being done by doctoral students, but it could be used similarly by all kinds of students who want to be involved in real-life scenarios outside of the lab. We’ve just gone over several such examples. But what about taking the MitoMobile to high schools, including those with limited resources who may not have access to research laboratories? We could use the MitoMobile to set up experiments using whatever animals are indigenous to that area. When you have exciting, live action experiments on site, it may motivate young people and may lead to an increased interest in the areas of science, technology, engineering, and mathematics, often know as STEM. We need more bright young people to become involved in this area. The MitoMobile delivers the science right to their door. All we need is a paved road to lead us there. I can’t think of any other module that can do that. Our MitoMobile has the potential to change the way we think, learn, and work to improve the human condition through basic cellular science.