New Migrating Stem Cells that Help Regeneration Could be a Focus for Stroke Treatment

Scientists are taking a closer look at a new type of stem cell that was discovered two years ago. Now, it looks as if these stem cells could be a new focus for stroke treatment.

The stem cell in question was first discovered in the brain and has the capacity to form new cells. Known as pericytes, these cells are located in the outer blood vessel wall and appear to actually be involved in the brain reaction following a stroke. Pericytes will drop out from the blood vessel, proliferate and migrate to the damaged brain area where they are then converted into microglia cells, the brain's inflammatory cells.

In order to actually see this happening, the researchers used a green fluorescent protein that bound to the cells. This allowed the scientists to track the pericytes to the damaged part of the brain. The migration itself took place about a week after a stroke.

"Pericytes are a fascinating cell type with many different properties and found at high density in the brain," said Gesine Paul-Visse, one of the researchers, in a news release. "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."

Currently, researchers aren't sure the exact role of microglia cells in regeneration after a stroke. However, the findings do reveal that pericytes 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," said Paul-Visse in a news release. "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 defense and repair mechanisms. 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."