Cohen P. et al / Laboratory of Molecular Metabolism / The Rockefeller University
Mouse aorta with immunofluorescence staining. In a new study of mice, beige adipose tissue is associated with lower blood pressure
We all know that there are two types of fat, brown and white. But according to a new study, beige fat, a mysterious type of fat cell proposed in 2008, may play an important role in heart health.
When we think about fat, we most often think about the famous fat cells. white fatwhich store excess calories like batteries, providing insulation and cushioning to our muscles, bones and organs.
But not all fat is white: mammals also have brown fat — named for its brownish color, thanks to a high concentration of iron-rich mitochondria — which does the opposite, burning energy to keep the body warm.
And then, there is beige fat.
First proposed in 2008, beige fat is located in white adipose tissue, but it works like brown fatburning energy efficiently when exposed to cold temperatures.
In recent years, a growing body of evidence has suggested that beige fat may play an important role in heart healthtells .
“There is enough data to affirm that beige fat is beneficial for human health”, he says Bruce Spiegelmanresearcher at Dana-Farber Cancer Institute and professor of cell biology and medicine at Harvard Medical School, who proposed the existence of beige fat and was the first to isolate beige fat cells in 2012. “For me, is now a settled scientific question“.
A new one, published on Thursday week in the magazine Science, adds evidence: it shows that beige fat helps lower blood pressure, a risk factor for heart disease and stroke.
The study, led by researchers at Rockefeller University, and carried out on rats, is based on previous work carried out on humanswhich show a correlation between brown fat and blood pressure lower.
In humans, brown fat is more prevalent in babies and is mainly located in deposits between the shoulder blades. Scientists believe that this fat, as in other mammals, is intended to keep us warm in cold temperatures. But as we age, most of this brown fat disappears.
What researchers call beige fat, in turn, is found above the diaphragm and along the neckoe of the upper part of the spine. Just like brown fat, burns energy to release heat when exposed to cold.
In 2021, Paul Cohen, an associate professor at Rockefeller University who studies obesity, published a paper showing that people with more brown fat had less likely to have type 2 diabetescoronary artery disease and high blood pressure. This raised new questions, says Cohen.
“This link between brown fat and hypertension It’s just an association?”, asks Cohen, who is also the author of the new article in Science. “Or is there a causal relationship?”
Cohen and his colleagues found that mice raised without beige fat had a higher blood pressure than mice with this type of fat — evidence of a causal relationship.
“If we just change the identity of the adipose tissue, we see that these mice have an increase in blood pressure,” he says. Mascha Koenenpostdoctoral researcher in Cohen’s lab and co-author of the new study.
The team also discovered that the beige fat removal influenced the production of an enzyme called QSOX1which can alter blood vessels and raise blood pressure.
This discovery is particularly interesting, says Biao Wangassociate professor at the University of California, San Francisco, who studies the development of adipose tissue.
By identifying a mechanism by which beige fat cells can regulate blood pressure, it opens the door to more studies in humans, and raises a new question, Wang adds: “what What else can beige fat secrete??”
Cohen and his colleagues hope the new study will help elucidate how beige and brown fat affect human health.
“We hope this type of work will lead to better, more personalized therapies based on specific characteristics of each patientwhich may be more suitable for controlling blood pressure”, concludes Cohen.
