Major national study looks to stem cells to aid recovery from stroke


Two of Canada’s top research networks are preparing to join forces to try to speed the development of the country’s first human trials of stem cells to repair brain damage after stroke.

Stem cells, the master cells that have the ability to differentiate or morph into other cell types, represent some of the strongest hope yet for future treatments to improve recovery after stroke.

One of the biggest challenges will be to get enough cells where they’re needed to replace lost neurons and “regenerate” or rewire damaged tissue, either by transplanting stem cells directly into the brain or using growth factors to mobilize endogenous stem cells within the body’s most complex organ.

“But now that we have adult stem cell populations that can, in theory, be made to become neurons and other brain cell types, we have an opportunity to really push the frontier a lot further and really address in a manner that has never been addressed before whether or not adult stem cells do indeed provide an avenue for repair after stroke,” says Dr. Samuel Weiss. The University of Calgary scientist was among the first in the world to discover stem cells in the adult brain.

If Canadian scientists could find a way to use stem cells to help stroke patients regain the use of an arm or leg, for example, or recover their speech, the stakes would be enormous.

“If we could make it work, it would be remarkable. The world would be beating a path to our doorstep,” Dr. Weiss says.

The goal is to bring experts within the Canadian Stroke Network and the Stem Cell Network together under a two-year effort to “carefully and systematically investigate” how stem cells taken from adult skin, bone marrow, muscle or brain could be reliably engineered to become functioning neurons in animal models of stroke.

The hope is that, within 12 to 24 months, researchers would know whether adult stem cell populations can contribute to brain repair in animals – and whether human adult stem cells could generate neurons that could then be tested in human clinical trials.

“Scientists are excited about the prospect that we could use skin or marrow stem cells to repair brain lesions,” Dr. Weiss explains. That’s the dream. But some fundamental questions remain.

“The big one is, if you’ve got a skin or bone marrow stem cell, can it become a neuron that has the same functional properties as one that comes from the nervous system? Not ‘maybe’. Yes or no. We need to start getting those types of answers because right now there’s ambiguity and uncertainty in the literature.

“If we put our minds together – and those are some pretty heavy hitting brains that are going to be coming together – there is an opportunity to answer these questions in a definitive fashion.”

The Canadian Stroke Network has the ability to measure behavior and functional recovery after stroke “better than anyone in the world, full stop,” Dr. Weiss says. “The Stem Cell Network has the best grouping of adult stem cell people in the world, full stop. What’s to stop us now from having a significant impact?

“Scientifically, it would make the Canadian effort the envy of the world, because nowhere in the world would you have this level of expertise in a controlled fashion.”