Exercise changes the genetic identity of your muscle cells

Muscle metabolism

New research may change the way we view our DNA and its ability to change. This could not only help improve the benefits of exercising, but also combat cancer and neurodegenerative diseases. Researchers from the Novo Nordisk Foundation Center for Metabolic Research at the University of Copenhagen, Karolinska Institute and Dublin University are behind the scientific breakthrough, which has just been published in the renowned scientific journal Cell.

The genetic changes in muscle cells during exercise is orchestrated by a methyl-group.

Researchers have long known that during exercise a genetic change in your muscle cells make the tissue better at burning fat and sugar. And it is this temporary betterment, which gradually makes the muscles stronger. Now researchers have made the remarkable discovery, that the genetic change in the muscle cell is so fundamental as to be compared to embryogenesis itself. 

“Each of the billions of cell in the human body contains a perfect copy of that persons DNA, which is like a private cook book with numerous different recipes or genes,” says Assistant Professor Romain Barrès from the Novo Nordisk Foundation Center for Basic Metabolic Research.

“What makes a skin cell different from, say, an eye cell or a muscle cell, are certain molecular bookmarks that are placed at different locations in the book and glue together the pages containing the recipes this particular cell does not need. A skin cell, for example, does not need to produce insulin, while a pancreatic cell should not produce pigment.”

Genetic book mark gives cells their identity

This book-mark is chemically seen a methyl-group, and this molecule gives each cell its identity. The methyl-groups are remodelled during embryogenesis, where they orchestrates the growth from stem cells to specified cells, and it is what makes your eye cells work as eye cells, pancreas cells as pancreas cells and skin cells as skin cells.

“We set out to understand what, biochemically speaking, happened in a muscle cell, to change the genes, so the muscles better burn fuel,” says Professor Juleen Zierath from University of Copenhagen and Karolinska Institute.

“And to our great surprise, it was the cellular identity tag, the methyl -group, which un-glues certain pages in the DNA cookbook so the cell starts producing enzymes that increase fuel burning in the surrounding muscle tissue. Who could have thought that something so fundamental as methyl groups, which in essence defines how your own personal DNA expresses itself in your own body, also partakes in something as transient as fuel burning? Because it is only when you move, that these pages are open – so to speak. When you stop exercising, the pages are glued back together almost instantly.”

Exercise manipulates cell identity

“It’s always been thought that tampering with this methyl-identity-tag in the DNA would lead to all kinds of trouble,” Romain Barrès continues. “But we have shown, that just by exercising, you, yourself manipulate the DNA of your cells. Our DNA is not as stable and unchangeable as previously thought.”

The researchers point out that these methyl-groups plays a role in healthy as well as diseased cells, and it opens up for completely new venues of research and possibilities.

“These methyl-molecules are also remodelled in cancer cells,” Juleen Zierath says. “So what would happen, if we could start manipulating with the identity of a cancer cell? Can we change it? Or what would happen if we could change the identity of a neurodegenerate brain cell? Could we help repair it?”

Pharmaceutical manipulation of cell identity could boost benefit of exercise

 “Or imagine getting the same effect of six hours of rock climbing from just 15 minutes on the running track,” Romain Barrès says.  “We also want to enhance the beneficial effects of exercising, which we know protects against obesity, diabetes, cancer, high blood pressure, depression and more. Something which is more important than ever with the global diabetes- and obesity-epidemics, where we need pharmaceuticals which can deal with the way we live and work today.”

The article “Acute Exercise Remodels Promoter Methylation in Human Skeletal Muscle” is published in the magazine CELL METABOLISM on 7 March 2012.

Recent Issues