Stem Cells Treat Monkeys With Parkinson’s

A team of researchers, led by Takuya Hayashi of the RIKEN Center for Molecular Imaging Science in Kobe, Japan, has succeeded in using stem cells to improve the motor skills in monkeys with Parkinson’s disease. The team’s report, published in the Journal of Clinical Investigation, suggests that stem cells from bone marrow might someday be a source for treatment of Parkinson’s in humans.

Eryn Brown, writing in the December 3 Los Angeles Times, quoted the lead researcher about the treatment with stem cell-derived neurons. “To the best of our knowledge, this study is the first to show restoration of dopaminergic function and motor behaviors in parkinsonian primate animals, ” he said. Parkinson’s seemed like a good candidate for stem cell-derived therapies. Brown noted, because people with the disorder have lost neurons in the brain that produce the neurotransmitter dopamine.

The team conducted its research on a group of 10 adult macaque monkeys in which they had induced Parkinson’s disease on the left side of the animals’ bodies. Removing bone marrow from the hip bones of the macaques, they isolated the mesenchymal stem cells and used a previously reported method to turn the mesenchymal stem cells into dopamine-producing neurons.

Hayashi and his colleagues studied the neurons they created in the lab to assure that they were indeed dopamine-producing, and then administered the treated cells to five of the monkeys. Each of the five monkeys received cells derived from its own bone marrow. The remaining five monkeys received sham treatments.

The animals who received the cell treatments showed improved motor function, Brown reported. By using PET scans and tissue analysis, the researchers determined that the implanted neurons continued producing small amounts of dopamine for at least nine months and none of the monkeys developed tumors. Because the cells came from the monkeys’ own bone marrow, tissue rejection was not an issue.

Before the treatment might be considered appropriate for humans, Hayashi said, further studies will be needed to improve the viability of the implanted cells and to boost their therapeutic effect. The team members hope that their approach “may expand the availability of cell sources for cell-based therapies for patients with Parkinson’s disease.”