Striking against stroke

Stroke is the leading cause of long-term disability and the second leading cause of death in Australia.

Yet doctors have limited treatment options for those left battling the debilitating effects of stroke.

Dr Alyson Miller, who heads RMIT’s Cerebrovascular and Stroke Laboratory, hopes to change that by discovering new ways to effectively treat brain damage caused by stroke.

“Unfortunately there is only one approved pharmacological therapy for stroke, the clot-buster rt-PA, which less than 5% of stroke patients are treated with,” she says.

“It is unquestionable therefore that advances in the treatment of stroke are of paramount importance. It is hoped that my research will provide new directions in the search for effective stroke therapies.”

Traditionally, stroke research has focused almost exclusively on finding new drugs to treat brain injury.

However, survival after stroke is not only defined by the extent of brain injury, but also by systemic complications such as infections and weight loss.

“Treatment of these complications, as well as brain injury, is therefore a necessary approach to improve stroke survival,” says Miller.

Finding a new way to prevent and treat stroke would make a huge difference to the 50,000 Australians who suffer new or recurrent strokes each year, according to the National Stroke Foundation.

Stroke survivors can suffer temporary or permanent disabilities including paralysis and pain. But those affected by stroke have reason to be hopeful.

A radical new hormone has taken Miller’s research in an exciting new direction.

In collaboration with researchers at Monash University, Miller and RMIT research partner Dr Sarah Spencer are investigating the potential of ghrelin, a hunger-stimulating hormone found in the stomach, as a novel treatment for stroke.

“We have experimental evidence that this stomach-derived hormone reduces damage to the brain and its blood vessels after stroke and may lessen infection and weight loss,” Miller says.

“So we believe ghrelin could be used to treat several aspects of stroke pathology.”

Miller’s research into the therapeutic potential of ghrelin was recently boosted by a National Health and Medical Research Council Project Grant worth almost $400,000.

The three-year project, “Investigating a Novel Agent to Limit Brain Injury and Post-Stroke Complications”, will investigate ghrelin’s potential for treating stroke pathology including vascular and neuronal injury, infections and weight loss.

Miller anticipates the outcomes of this research will provide a strong case for clinical trials of ghrelin and may ultimately lead to the development of an effective new stroke therapy.

This new step for stroke research builds on years of work focused on understanding the causes of brain artery damage that accompanies stroke risk factors, such as high blood pressure and high cholesterol, and stroke itself.

Miller, who has published 41 research articles in this research area, says her work over the past decade has shed light on the role of toxic oxygen radicals in brain artery damage.

“My research has shown that a family of enzymes called the NADPH oxidases produce large amounts of toxic oxygen radicals within brain arteries, and are important contributors to brain artery damage and also brain injury in a range of diseases including stroke,” she says.

“Excitingly, we have since found that ghrelin is very effective in blocking the NADPH oxidases, a finding that galvanised our current research on ghrelin as a novel stroke therapy.”

(Source: RMIT University)