Ottawa researcher finds potential muscle rebuilder

Protein molecule stimulates stem cells

For years Michael Rudnicki has watched children with muscular dystrophy, and adults with other diseases, whose muscles are wasting away.

Today the Ottawa medical researcher says he’s optimistic about a new tool that uses a protein produced naturally in our bodies to help muscle cells repair themselves.

It won’t be a cure for Duchenne muscular dystrophy or other diseases, he cautions. But like insulin for diabetes, it might be a helpful tool.

Rudnicki is a senior researcher at The Ottawa Hospital Research Institute and University of Ottawa.

He’s working with a protein molecule called Wnt7a, one of a family of proteins that play a key role in stimulating stem cells and helping tissues to regenerate.

Put it into muscle cells, he reasoned, and it could help those cells repair themselves. It could also help to produce new muscles tissue from stem cells.

Such a treatment “could have a huge impact,” he said. The protein “stimulates the intrinsic repair process ... and also stimulates muscle fibre strength. So it acts at multiple levels to give you stronger and better muscle.”

But there’s a problem. This protein molecule is nearly impossible to manufacture in the lab.

The new discovery from Rudnicki’s team, however, is that just part of the molecule appears to do the same job — and that bit is much easier to manufacture.

They have published their work in a major science journal, Nature Communications, and hope to start the first stage of human trials in early 2015. The protein is manufactured by Fate Therapeutics, Inc., a biopharmaceutical company co-founded by Rudnicki.

“Muscle-wasting diseases represent a huge, huge, unmet clinical need for which there is no treatment,” he said.

Some elderly people start losing muscle mass and become weaker. Some cancers can cause the loss of muscle as well. So can hip or knee surgery or a stay in intensive care. And some people lose the muscles that give us bladder control as they age.

Many of these conditions, he said, could be helped by treatment that makes the body repair and rebuild muscles.

His main, focus, however, is Duchenne muscular dystrophy, which currently is fatal to all the children who have it.

The U.S. Food and Drug Administration has declared muscular dystrophy to be an “orphan” condition, meaning one where little research is going on, and this means the trials can be sped up.

“This will not cure the disease,” he warned. “And the first form will be an injectable that will treat an individual muscle at a time,” targeting the muscles that allow these children to breathe and swallow.

“Down the road, it’s possible that forms will be developed that can be delivered through the blood system to reach all muscles. But we’re not there yet.”

And other drugs would still be needed with it. “Just like AIDS, you need a cocktail.”

He said he believes the other proteins in the same family might also have roles to play.

So far, the protein works in mice and in human cells in the test tube. But muscular dystrophy “is a tough nut to crack,” he said.