Scientists Pinpoint Flaw, Offer New Promise for Stroke Treatment
April 29, 2017
The best treatment doctors currently have for stroke can accelerate the death of brain cells in addition to dissolving
blood clots, researchers report in the journal Nature Medicine. But they also found good news: Another drug currently used to
treat patients with severe sepsis counters the harmful effects, offering the possibility that a combination of two
already-approved drugs might offer a powerful new stroke treatment that would give doctors a bigger window of time to treat
patients.
The work is the result of a longstanding collaboration between scientists at the University of Rochester Medical Center and
at The Scripps Research Institute in La Jolla, CA. The team found that the clot-buster tPA (tissue plasminogen activator) can
magnify the harmful effects of stroke in mice and in human cells, and that a compound known as APC (activated protein C)
counters the harmful effects.
"TPA has been a great therapy for some patients, but right now it's available to a tiny minority of patients. We hope to
extend the window of opportunity that tPA could be given, by protecting the brain against its toxic effects," says Berislav
Zlokovict neuroscientist who led the research thanks to funding from the National Heart, Lung, and Blood Institute. "This
holds great promise for stroke therapy."
TPA is best known as a clot buster useful for patients who have the most common type of stroke, where a blood clot blocks
blood flow to a portion of the brain, cutting off oxygen. The trauma causes more and more brain cells to die as they try to
cope with the damage. The result can be a devastating brain injury that incapacitates the person for life.
TPA can prevent the damage by dissolving the clot and restoring the flow of oxygen - but the drug must be given to patients
within three hours of the onset of stroke symptoms. That's a big reason why just a tiny fraction of patients benefit from the
drug: Zlokovic estimates that the drug reaches only about three percent of patients who are eligible, and of those, less than
1 in 10 benefits.
The window of opportunity is so short largely because tPA is capable of doing additional damage if not given immediately.
While doctors know that tPA can cause damage, the research team observed more extensive damage than expected…………
CONTINUES……….www.scripps.edu