Otttawa scientists have discovered a trigger that turns muscle stem cells into brown fat, a form of good fat that could play a critical role in the fight against obesity. Fighting fat with fat? The recent stem cell discovery identified a potential obesity treatment, says research from the Ottawa Hospital Research Institute. The study is a collaboration that included researchers from the Ottawa Hospital Research Institute, University of Ottawa, University of Ottawa Heart Institute, Nordion, Erasmus Medical Centre in the Netherlands and University of Copenhagen.

The findings from Dr. Michael Rudnicki's lab, based at the Ottawa Hospital Research Institute, were published online ahead of print on February 5, 2013 in the prestigious journal Cell Metabolism. You can check out the abstract of the study, "MicroRNA-133 Controls Brown Adipose Determination in Skeletal Muscle Satellite Cells by Targeting Prdm16."

"This discovery significantly advances our ability to harness this good fat in the battle against bad fat and all the associated health risks that come with being overweight and obese," says Dr. Rudnicki, according to the February 5, 2013 news release, "Fighting fat with fat: Stem cell discovery identifies potential obesity treatment."

Rudnicki is a senior scientist and director for the Regenerative Medicine Program and Sprott Centre for Stem Cell Research at the Ottawa Hospital Research Institute. He's also a Canada Research Chair in Molecular Genetics and professor in the Faculty of Medicine at the University of Ottawa.

Globally, obesity is the fifth leading risk for death, with an estimated 2.8 million people dying every year from the effects of being overweight or obese, according to the World Health Organization

The Public Health Agency of Canada estimates that 25% of Canadian adults are obese. In 2007, Dr. Rudnicki led a team that was the first to prove the existence of adult skeletal muscle stem cells. In the paper published today, Dr. Rudnicki now shows (again for the first time) that these adult muscle stem cells not only have the ability to produce muscle fibres, but also to become brown fat. Brown fat is an energy-burning tissue that is important to the body's ability to keep warm and regulate temperature. In addition, more brown fat is associated with less obesity.

Perhaps more importantly, the paper identifies how adult muscle stem cells become brown fat. The key is a small gene regulator called microRNA-133, or miR-133. When miR-133 is present, the stem cells turn into muscle fibre; when reduced, the stem cells become brown fat.

The recent study reveals how adult muscle stem cells become brown fat

Dr. Rudnicki's lab showed that adult mice injected with an agent to reduce miR-133, called an antisense oligonucleotide or ASO, produced more brown fat, were protected from obesity and had an improved ability to process glucose. In addition, the local injection into the hind leg muscle led to increased energy production throughout the bodyan effect observed after four months.

Using an ASO to treat disease by reducing the levels of specific microRNAs is a method that is already in human clinical trials. However, a potential treatment using miR-133 to combat obesity is still years away.

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How stem cells can fight obesity - Sacramento Holistic ...