A Longer Window for Treating Stroke?
There is an urgent need for developing new drugs that can alleviate the harmful effects of a stroke because current treatment possibilities using thrombolysis are limited to the first hours following a stroke. To that end, researchers at Lund University in Sweden are studying brain cells known as pericytes. The team discovered in 2012 that pericytes can for new cells. According to a release from the university, the 2014 research shows for the first time that pericytes are directly involved in the reaction of the brain tissue after stroke. Pericytes are known to contribute to tissue repair in a number of organs, and the researchers believe that their reparative properties could also apply to the brain.
The release quotes senior author Gesine Paul-Visse as saying, “Pericytes are a fascinating cell type with many different properties and found at high density in the brain. It was surprising that a pericyte subtype is so strongly activated after a stroke. The fact that pericytes can be converted into microglia, which have an important function in the brain after a stroke, was an unexpected finding that opens up a new possibility to influence inflammation associated with a stroke.”
Using a green fluorescent protein bound to the pericytes, the researchers were able to track the cells’ path to the damaged part of the brain. The migration takes place within a week after a stroke. When the cells reach the site of damage they are converted into microglia cells, the “cleaners” of the central nervous system. Inflammation can, however, have both positive reparative effects and negative effects on the damaged tissue. The exact role of microglia cells in the regeneration after a stroke is not entirely clear, but the Sedish scientists say that pericytes do play an important role in protecting the brain against disease and injury.
“We now need to elucidate how pericytes affect the brain’s recovery following a stroke. Our findings put pericytes in focus as a new target for brain repair and future research will help us understand more about the brain’s own defence and repair mechanisms,” Gesine Paul-Visse said. “Because inflammation following a stroke is an event that continues after the acute stage, we hope that targeting pericytes in the subacute phase after stroke, i.e. within a longer time window following the onset of stroke, may influence the outcome.”