SEP 19, 2018 6:49 PM PDT

A Molecule That Coaxes Muscles to Burn More Fat

WRITTEN BY: Carmen Leitch

Scientists have identified an important molecule that is critical to metabolism. Called sarcolipin, this peptide that is only present in muscles can promote energy expenditure and increase fat oxidation. Sarcolipin causes muscle to drive the cell’s power plants, mitochondria, to make more energy by burning fat. This work, by scientists at Sanford Burnham Prebys Medical Discovery Institute (SBP), has been published in Cell Reports.

Image credit: Freestockphotos

"This study shows a direct relationship between sarcolipin and energy metabolism," says Muthu Periasamy, Ph.D., senior author of the paper and professor at SBP Lake Nona. "This mechanism is intrinsic to muscle and generates heat at the expense of fat burning."

It’s known that cold temperatures and exercise increase the amount of energy that muscles burn. Sarcolipin makes that energy expenditure less efficient, burning more. It forces muscles to move calcium ions into an organelle called the sarcoplasmic reticulum with SERCA, a calcium ion transporter. The process needs a lot of energy, in the form of ATP, which SERCA uses to move the ions. But if sarcolipin binds to SERCA, activity is uncoupled; that increases ATP consumption and decreases efficiency. 

"When you exercise, your muscle makes more mitochondria and oxidizes more fat. Sarcolipin is the missing link. It's recruited during exercise or cold exposure and alters calcium cycling to increase mitochondria biogenesis and fat burning," explained Periasamy.

The researchers manipulated sarcolipin levels in a mouse model and found that without sarcolipin, mice had cells with fewer mitochondria. The mice also had difficulty burning fat; there was more of it in their muscle, a disorder called lipotoxicity. Lipotoxicity is known to cause insulin resistance, which can result in type 2 diabetes. Animals with more sarcolipin had increased numbers of mitochondria and higher fat oxidation.

"When we feed mice with more sarcolipin a high-fat diet, they don't accumulate any fat in their muscle, and they don't develop insulin resistance and type 2 diabetes," said the first author of the report, Santosh Maurya, Ph.D., staff scientist at SBP Lake Nona.

It’s possible that sarcolipin may help people with metabolic disorders like diabetes or obesity, but more work will be necessary to know.

"Researchers have already shown that extreme obesity reduces sarcolipin function," noted Periasamy. "There might be a therapeutic window to increase sarcolipin recruitment to burn more energy. This strategy could help people with metabolic conditions, as well as those who have difficulty exercising.

"We have more SERCA pumps than we need. Some are bound by sarcolipin, but it only binds around 25 percent of SERCA pumps at any one time. We would need to find drugs that increase [the] efficiency of sarcolipin uncoupling SERCA."

Periasamy is featured discussing his work in the following video.


Sources: AAAS/Eurekalert! via Sanford Burnham Presbys Medical Discovery Institute, Cell Reports

About the Author
  • Experienced research scientist and technical expert with authorships on 28 peer-reviewed publications, traveler to over 60 countries, published photographer and internationally-exhibited painter, volunteer trained in disaster-response, CPR and DV counseling.
You May Also Like
MAR 08, 2020
Cell & Molecular Biology
MAR 08, 2020
How a Decoy Strategy Helps Cells Evade the Effects of Pathogens
Scientists have identified a strategy used by cells to shield them from the toxins that can be released by dangerous bac ...
MAR 16, 2020
Genetics & Genomics
MAR 16, 2020
How To: Recombinant Protein Construct Design
Creating recombinant proteins has become much easier over the past few decades. However, those with the skills to do des ...
MAR 27, 2020
Genetics & Genomics
MAR 27, 2020
Expanding the Genomic Regions That Can Be Targeted With CRISPR
CRISPR gene-editing technology has sparked a revolution in biomedical research and is poised to have far-reaching applic ...
APR 02, 2020
Cell & Molecular Biology
APR 02, 2020
Cooling Injured Brain Cells Can Aid Recovery
According to the CDC, in 2014 there were around 2.87 million incidences of TBI-related ER visits.
APR 26, 2020
Cell & Molecular Biology
APR 26, 2020
Researchers Remotely Trigger the Release of Hormones
It may one day be possible to treat hormone-related diseases using this method.
MAY 12, 2020
Genetics & Genomics
MAY 12, 2020
Learning More About Why Some Diseases Have a Sex Bias
The biological differences between men and women go beyond the things we're aware of like the sex chromosomes and hormon ...
Loading Comments...