Brown Fat Research Could Pay Off for Type 2 Diabetes
Drs. Aaron Cypess &
C. Ronald Kahn
Friday, December 18, 2009
Scientists have long known about brown fat, a “good” fat found in babies and children that increases the expenditure of energy. But they’ve generally assumed that brown fat doesn’t play an active role in adults. Until last spring, when Joslin’s Aaron Cypess, M.D., Ph.D., and his colleagues demonstrated that brown fat can remain active in adults.
The discovery raises hopes that brown fat eventually could aid treatments for obesity, and type 2 diabetes. Earlier this year, Dr. Cypess, a Joslin research associate and physician, answered six questions about his work.
What did you and your colleagues find about brown fat?
Not only did we find active brown fat in adult humans, we found important differences in the amount of brown fat based on a variety of factors such as age, sex and, most importantly, level of obesity.
One finding which is intriguing is that men have brown fat half as frequently as women. (Other researchers had seen this before.) Why do women have it more often? It’s a fundamental question, and we are looking at several possible explanations.
We also know that as you get older, you tend to have less brown fat. We found that, among old people, if you are more obese you have substantially less brown fat. And we found that if you take beta blocker medications (a class of drugs used for certain cardiac conditions), brown fat is reduced or eliminated.
We also saw that people’s maximum brown fat activity was in the winter. That’s one of the advantages of living in Boston!
What’s the promise of brown fat research?
If you can increase the amount of brown fat in the body and then turn it on, you’ll burn up several hundred extra calories a day, if you do it right. That is fascinating. And that’s what we’re working on now.
What are your next steps?
We’re doing two things.
One is figuring out, how can you best measure brown fat in the body? This is a challenge, because fat is special. Everybody’s got the same bones in their hands, but fat doesn’t work like that. Fat’s spread out everywhere. It’s a tissue that’s changing in size, and it’s all over the place, and not in a predictable way.
Second, [Joslin Assistant Investigator] Yu-Hua Tseng published a paper in Nature last year showing that a protein called BMP-7 increases brown fat in mice, and those mice gained less weight than normal mice when they ate a diet high in fat.
It turns out that BMP-7 is given to human beings for bone surgery. We’ll study people who are already getting BMP-7 for their surgeries, to see if their brown fat grows and has an effect on them.
As an M.D./Ph.D., do you juggle research and the clinic?
Yes, I see patients and I do research. I wouldn’t want to do just one. A number of other people here also do that, including Drs. Gordon Weir, Robert Stanton, Mary Elizabeth Patti and Allison Goldfine.
I’m only in the clinic half a day a week, but it’s an integral part of my experience here. I see patients because I like making a difference and I like talking to people. Being a clinician is very rewarding from minute to minute and day to day.
Ideally, you’re helping your patients by what you’re doing in your research, and your research is informing you on how to treat your patients.
After your fellowship in endocrinology at Beth Israel Deaconess, you ended up here. How did you choose Joslin?
I joined Dr. Ronald Kahn’s lab for two main reasons.
One was the kinds of projects he was working on, which were similar to what I had studied in graduate school, so I could apply some of the research techniques that I had learned.
The other was mentoring. Ron meets with his postdoctoral researchers once a week. It’s a way of really mentoring that is rare and very important. It’s no surprise that, for example, Jeffrey Flier [Dean of Harvard Medical School] was one of Ron’s trainees.
You also can walk up to anybody at Joslin and ask them a question. You have the conviviality and convenience of being in a small institution.
And yet, you’re part of Harvard Medical School, which means that you can go to Beth Israel, to Brigham, to MGH, to Children’s. You can work with everybody. I’ve established collaborations with a lot of people. That’s great fun, and it’s how we were able to do the brown fat research.
Aaron Cypess, MD, PhD talks to Inside Joslin about his research into brown fat.
Joslin Research Updates
Page last updated: March 10, 2014