Saving cells to improve stroke recovery
Researchers at the University of Calgary’s Hotchkiss Brain Institute are developing new tools to save brain tissue when blood flow is cut off during a stroke and oxygen levels crash.
“If you can protect brain tissue during a stroke you can greatly improve recovery,” says cell biologist Dr. Roger Thompson, whose research focuses on how tissues in the body respond to changes in oxygen levels.
Dr. Thompson’s seven-member research team is focused on an ion channel – a pore in the membrane of the neuron (brain cell) – that stays open during a stroke and results in cell death.
“What my lab has been doing is trying to design drugs that can keep this channel closed and protect the brain tissue,” says Dr. Thompson, a researcher in the Heart and Stroke Foundation Canadian Partnership for Stroke Recovery.
In 2016, his team published a study in the prestigious journal Nature Neuroscience that showed how a small protein they designed to close the channel allowed rodents with strokes to recover from their injury.
“If you can get neuroprotection and recovery together you get the best-case scenario,” he explains.
The Thompson team is now studying the protein, called Pannexin-308, in other relevant models to confirm that it works and to show that it’s safe for people. Ideally, it will one day lead to the development of a drug that can be given to stroke patients in an ambulance or the emergency room.
In addition to studying how to protect the brain from loss of blood flow, Dr. Thompson’s lab is also looking at ways to protect the brain when blood flow returns to the area affected by stroke.
“Dr. Andrew Demchuk, head of the Calgary Stroke Program, identified that reperfusion (the return of blood flow to the area of the brain affected by stroke) injury is becoming more and more a concern,” Dr. Thompson says. “Physicians are actually getting quite good at getting the clots out through surgery and use of (the clot-busting drug) tPA. But what they are finding is that reperfusion is causing injuries that hamper recovery.”
Part of his lab is shifting focus to understand reperfusion injuries with the idea that drugs designed to protect neurons will actually help reduce ongoing cell death after the stroke.
Dr. Thompson says the thing that really sets Calgary apart from other research centres is the “excellent dialogue between the clinical stroke people, who are among the best in the world, and the basic scientists.” Hotchkiss Brain Institute has nine neuro teams, one of which is co-led by Dr. Thompson and focused on stroke. He describes it as a “fantastic resource for getting the clinicians and basic scientists in the same room to talk.”
And being part of the Canadian Partnership for Stroke Recovery links the Calgary group with research teams across the country to develop new approaches and big ideas for enhancing recovery.
“You can answer more complex problems if you have more and more people working together.”
In the end, he says it’s likely a combination approach developed by people working across the continuum of stroke recovery research – studying everything from exercise to medication – that will be the game-changer for care.