Post-stroke aftermath
One of the most dangerous periods for a person who has experienced a stroke or cardiac arrest is the period following the attack, when blood resumes flowing to the brain’s neurons. Gary Krause, MD, professor of emergency medicine, just received a five-year, $2.1 million grant from the National Institute for Neurological Disorders and Stroke to conduct research on that interruption and resumption of blood flow, termed reperfusion. “We’re trying to figure out what this reperfusion injury is – what’s involved in it – and if we can intervene in it to somehow cut down the amount of injury that continues to progress for at least the first 24 hours after the stroke has happened,” he explained. Over the last four years, Dr. Krause has learned that the death of vulnerable neurons in the brain’s gray matter – the cerebral cortex and hippocampus – seems to be associated with the inhibition of protein synthesis, and that this inhibition is associated with reperfusion. He and his research team found that the body regulates the rate of protein synthesis by changing the activity level of a control protein known as eIF2. During reperfusion, an unknown kinase turns off the eIF2 protein, he said. With the new grant, Dr. Krause and co-investigators Drs. Blaine White and Donald DeGracia of emergency medicine, and Larry Grossman of molecular biology, will study both the kinase and a regulatory protein called p67, which normally protects the eIF2 protein from the kinase. “We’re trying to determine whether the kinase has been turned on inappropriately, which turns off the eIF2, or whether the protector is just missing,” he said. “We don’t know which it is, but we’ve got five years to find out.” Dr. Krause remarked that the work should be a particularly important addition to the pool of stroke research. “We’re trying to figure out what the reperfusion injury is, number one, to see what we can do about fixing it. Until we know what it is, we can only guess at the therapy.”
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