On Friday’s closing day of the 2014 World Stem Cell Summit a panel of three researchers working on neurodegenerative diseases drove home the importance of paying attention to the environment that surrounds stem cells after transplant.

CIRM grantee Evan Snyder from the Sanford-Burnham Institute noted that most of the neurologic diseases people are looking at are conditions associated with aging and the cellular makeup of the brain changes as we get older, adding that most of the diseases result from chronic states that have existed over many years. He contrasted this against mouse models of the disease, which usually involve artificially recreating the disease and treating shortly after the injury happens.

“In stem cell therapies there is a dialogue between the transplanted cells and the recipient. The host influences the fate of the stem cells.”

He noted that the patients we will be treating have generally had long-term degeneration and asked if we might be able to develop drugs that effect the environment where the stem cells will be placed so that it mimics more closely the environment found in the animal model in the acute phase, that is right after injury.

One aspect of the environment in the brain in most patients with neurodegeneration is chronic inflammation. Another CIRM grantee on the panel, Jeanne Loring of the Scripps Research Institute, discussed a project her team hopes will take advantage of the inflammation that occurs in Alzheimer’s disease. They are loading nerve stem cells with an enzyme that can degrade the plaque that accumulates in nerves in the disease. Because stem cells home to inflammation, they hypothesize that the stem cells will be drawn to deliver their cargo to the nerves with the worst plaque.

The third panelist, Erzi Kokovay of the University of Texas Health Science Center in San Antonio, described the changes in the brain as we age in a bit more detail. She described infiltration of cells called microglia that researchers will need to take into account when they plan to transplant stem cells in the brain.

While on the surface this all may sound like another road block to getting to the stem cell cures we all want, the presentation actually made me optimistic that we are starting to learn enough about the field that we are more likely to get it right when we start to treat some of these devastating brain diseases.

Don Gibbons