Stem cells show promise in Parkinson’s

The symptoms of Parkinson’s disease (PD)—muscle rigidity, tremor and a general slowing of movement—have been successfully treated in monkeys using human stem cells.

PD is caused when large numbers of dopamine-producing cells (DA cells) die off in a brain region known as the substantia nigra.

In the July 17 issue of Proceedings of the National Academy of Sciences, a team headed by D. Eugene Redmond Jr., M.D., professor of psychiatry and neurosurgery, reports that human neural stem cells implanted into one side of the substantia nigra in monkeys with severe Parkinsonian symptoms migrated and survived on both sides, where many displayed biochemical markers indicating that they had matured into DA cells. Other implanted cells also migrated to key regions and appeared to play a nurturing role, creating a protective microenvironment that restored the function of the monkeys’ own surviving DA cells.

Over a four-month period, the monkeys treated with stem cells had vastly improved. “Not only are stem cells a potential source of replacement cells,” says Redmond, “they also seem to have a whole variety of effects that normalize other abnormalities.”