A new study in mice reports that admistering pharmacological doses of a "sponge-like" molecule that occurs naturally in the human body may stave off brain damage from stroke.
One of the study's two senior co-authors, neuroimmunologist Larry Steinman, MD, has published several articles in the past few years on the substance's anti-inflammatory properties and possible therapeutic benefits in indications ranging from multiple sclerosis (his specialty) to heart attack.
Strokes - there's a new one every 40 seconds in North America alone - are caused by a sudden drop in the flow of blood to the brain resulting from a clot or, less often, bleeding. Here are the grim statistics:
The largest single cause of severe neurological disability and the third-leading cause of death in the United States, stroke accounts for an estimated $74 billion annually in related costs, including treatment and additional assistance for the three of every four stroke patients whose ability to perform the activities of daily life is impaired. One of every three stroke patients is under the age of 65. In all, there are 5.4 million stroke survivors in the United States and 15 million worldwide.
The only currently approved treatment, tissue plasminogen activator or tPA, is not only costly, but must be given within 4.5 hours of the incident to be effective. That's already tough, given the initial denial that often prevents those experiencing a stroke from immediately getting help. Further complicating the logistics is the fact that before administering tPA to a patient, doctors have to first run a brain scan to make sure the patient's stroke was caused by a clot, not by bleeding. (If it's the latter, tPA, which works by dissolving clots, would make it even worse.)
The substance tested in the study, alpha-B-crystallin, is produced in healthy tissues as well as in the brain in response to a stroke - but, according to neurosurgeon Gary Steinberg, MD, PhD, the study's other senior co-author, not in sufficient amounts to fully quench the inflammatory mayhem that follows. Indeed, much of the damage caused by stroke is due not to the initial blockage of blood flow to affected brain areas, but to the ensuing storm of inflammatory activity brought about by a scream of molecular sirens, an ensuing police riot of trigger-happy immune cells squirting brain-cell-breaking oxidants.
Alpha-B-crystalline seems to act like a sponge, soaking up all these crazed inflammatory hotheads, shrinking the ultimate size of the stroke lesion, and apparently reducing the resulting behavioral deficits even when given 12 hours after the stroke. At least in mice. (Stay tuned.)
Photo by Pobre.ch