Strength in numbers: The Mito Test makes waves

No needles, scalpels, or stitches are necessary for this test.

No large machines or magnets. No biopsies. No blood will be drawn.

Instead, the work will be done by domino-sized sensors of the near-infrared spectrometer taped to your body. Its waves of light flow painlessly through your skin, seeking out measurements from your muscles. These readings return to a computer that translates them into data—in this case, how muscle mitochondria react and recover from exercise.

This test is known around the College of Education's Department of Kinesiology as the NIRS Mito Test. It has evolved over several years thanks to the tinkering of professor Kevin McCully, but the basic facts remain the same: It's non-invasive, which means it can be used on a variety of patients; it's inexpensive, which means it can be used in a variety of situations; and it has the potential to become a standard baseline-measuring test in labs and clinics around the world.

Put simply, the Mito Test uses patented software developed by McCully and other College of Education researchers to measure how fast muscles recover from a bout of exercise. The faster you recover, the more mitochondria you have—an indicator of overall muscle health. With a sprawling network of alumni who have developed their own lines of research around the test, as well as tutorials given to researchers both nationally and internationally, this test to measure muscle mitochondria, and the device developed at the College of Education to conduct it, is gaining a larger foothold. Assistant professor Jarrod Call, whose Skeletal Muscle Dysfunction Lab in the College of Education often collaborates with McCully's Non-Invasive Muscle Physiology Lab, where the NIRS device is housed, says the mitochondria test has the potential to become as ubiquitous in labs as the VO2 Max, a common test that measures oxygen consumption.

"The VO2 Max—every exercise physiology lab uses that to characterize any study participant," says Call. "The advancement of the NIRS technology and Kevin's application of it opens the possibility that we could have the same opportunity to test mitochondria in the same way."

A tree takes root On any given day, visitors to McCully's lab can find both undergraduate and graduate students using the NIRS device to conduct their own mitochondria research. The ease of the test allows students and clinicians of all experience levels to use it, McCully says. The root of the test came from McCully's desire to study muscle fatigue. After doing postdoctoral work investigating muscle metabolism in animals, he began to gravitate toward humans—specifically, diseased populations.

At the time, mitochondria tests were conducted using magnets, typically MRIs. The problem is, those tests get expensive, and they aren't right for every person. "I decided to learn how to do this near-infrared test, and it was less expensive," says McCully. "So, coming to UGA, I took the non-invasive experience I'd learned, took the ultrasound experience, took the animal experience, and said, 'Can I adapt the methodology to be more precise?'"

But testing on humans is much less precise than testing on animals—you can't control what they have for breakfast, for example, or the amount of exercise they do on a given day. So, for McCully, developing the Mito Test became an exercise in precision: How could he minimize outside factors and develop a test that would deliver precise results?

Terence Ryan (Ph.D. '13) was one of the first graduate students to work on the early iterations of the Mito Test—his name is also on the patent for the calculations done by the test. At the time, he says, he and McCully learned about a similar test in Japan. "And so, we started to test it out and through a number of failures we came up with a method to correct the data," says Ryan, now an assistant professor at the University of Florida. "That sort of spurred the patent application at UGA, and so over the next two to three years we did a whole bunch of studies to demonstrate the validity of the test." Ryan went from UGA to a postdoctoral position at Eastern Carolina University, where he worked for five years before landing his current position at UF last year. McCully's lab was instrumental in his research experience and has had a large hand in shaping the work he does today.

"In my lab, all we do is study mitochondria," says Ryan, noting that the mitochondria are the parts of the cell that drive its energy. The function of the mitochondria is critical to the function of the cell. "We see most pathologies have some sort of impediment to mitochondria function, so at this point we're looking at mitochondria function. I started at UGA developing this test of mitochondria function, and now we're working on the components of those diseases."

Branching out Ryan is one of many alumni who took the hands-on training they received measuring mitochondria in the Non-Invasive Muscle Physiology Lab and applied it to further research in their own areas. From postdoctorate positions to private clinics to faculty positions and research labs, the NIRS technology, via the Mito Test, is gaining a wider audience thanks to the Department of Kinesiology's alumni network.

Daniel Shill (M.S. '16), now a third-year doctoral student at the University of Maryland, says he thanks kinesiology faculty for helping to shape his research pathway. As a student of Nathan Jenkins, (B.S.Ed. '05, M.S. '05) an associate professor in the College's Department of Kinesiology and director of the Integrative Cardiovascular Physiology Lab, Shill used the NIRS method for his master's thesis and says it's now part of his research toolbox.

"Now I'm doing a lot of cell culture work, so I've moved away from the human side and now doing more mechanistic research, like cells in a petri dish," he says. "But it was nice that I got that perspective of the mitochondria test. It's nice to have those different tools in my toolkit, to be able to translate it all up into a functional outcome."

The experience with the Mito Test also adds to his marketability once he graduates.

"It goes back to that whole concept of translational medicine," he says. "It's just putting more tools in my science toolbox, so once I graduate and get a job, I can market myself better because I have all these different experiences under my belt. It's given me a unique perspective."

On the other end of the spectrum, Ashraf Gorgey discovered the uses of the Mito Test years after leaving UGA. During a fellowship studying spinal cord medicine, he realized the large effect mitochondria health had on his research. At the time, the main technique to gather mitochondria was a biopsy, but that was often problematic.

"Then it clicked with what McCully was doing in his lab, and I started to learn more about NIRS and how it would apply," says Gorgey (Ph.D. '05). "And we've been using it on a regular basis, in a number of studies, and it's much simpler, much easier. We can't believe we're measuring mitochondria by just using this tool, which is very simple. Once you figure it out, you can do it in any patient."

Gorgey now splits his time between the Richmond VA Medical Center, where he directs spinal cord research, and Virginia Commonwealth University, where he is an associate professor. He uses the Mito Test in both clinical and research settings and says the non-invasive aspect of the test is a game-changer for many patients—many of whom already are in delicate states or can't tolerate more invasive tests. "I think this will save a lot of time, effort, money and resources, and give the right direction to your patients," he says.

Christopher Black (M.A. '03, Ph.D. '07) uses NIRS technology as a supplemental test in his lab at the University of Oklahoma, where he is an assistant professor, to gauge the function of the muscle mitochondria in relation to other measurements. Black first joined McCully's lab in 2001—"I sort of stumbled into exercise physiology and stumbled into McCully's lab," he says—but the happenstance meeting has turned into a long collaboration.

Today, Black studies the function of the neuromuscular system, such as how it tells our muscles to turn off and on to exercise, and specifically, pain after exercise.

Black echoed others' praises of the NIRS technology and the Mito Test specifically: It's non-invasive, it's cost-effective, and it's even portable. "You can take it out into the community if you want," he says. "Those things make it a very attractive measure to tell us something that's pretty sophisticated about how people's muscles work."

Planting more seeds In tracing the reach of the Mito Test, McCully notes it branches beyond alumni. His lab has collaborated with researchers from the University of Alabama at Birmingham, Auburn University, and Penn State. There's even a researcher from the Netherlands who traveled to Athens for training on the test.

The Mito Test also plants seeds of collaboration within the Department of Kinesiology. While McCully's lab studies the functions of larger muscle systems, Call's focuses on cellular functions and a third, run by Jenkins, investigates prevention and treatment of metabolic diseases.

"I'm interested in this big paradigm, this big puzzle. And with the resources that the lab next door provides, we do have this kind of 'super lab' model where we collaborate on different things," says Jenkins. "It increases our capabilities, and we have quite a diverse toolbox; it enhances our ability to answer a lot of questions."

Shill agrees, noting the influence that collaboration had on his research. "Jenkins and McCully collaborated on, I believe, three different projects when I was there, and that was really cool to see labs collaborate like that and put two different pieces of technology together that you wouldn't necessarily see together," he says.

And, as more researchers continue to gain exposure and access to the technology, its capabilities will continue to grow.

"It really gets into a broad impact," adds Call, recalling a paper written by a California researcher who had limited experience working with NIRS technology, and yet was singing its praises. Both Call and Jenkins wrote responses, also in support of the technology. "The advance of the NIRS technology, and Kevin's application of it opens the possibility that we could have the same opportunity to test mitochondria in the same way. The same broad applications."