This is the first time researchers have tested the use of the reprogrammed stem cells in the human brain.
In October, researchers at Kyoto University transplanted cells generated from induced pluripotent stem cells into the brain of a man with Parkinson’s disease, the scientists reported Friday (November 9) at a press conference. This is the first time that researchers have tested the use of iPSCs in the human brain, and Parkinson’s disease is only among a handful of conditions for which iPSC-based therapies have been tested in humans at all, Nature reports.
In Parkinson’s disease, cells that produce the neurotransmitter dopamine die off, resulting in tremors and other movement problems. Although there are treatments that can alleviate some symptoms, there is currently no cure for the disease.
The transplanted cells in this treatment are precursors to dopamine-producing neurons, and the hope is that they will restore the dopamine deficit and relieve symptoms. A very similar procedure reduced movement difficulties in monkeys whose dopaminergic neurons had been experimentally poisoned to model Parkinson’s disease.
Kyoto University stem cell researcher Jun Takahashi and colleagues began with a stock of iPSCs, which they had previously reprogrammed from an anonymous donor’s skin cells. They then differentiated the iPSCs into dopaminergic-neuron precursors. In a three-hour surgery, neurosurgeon Takayuki Kikuchi implanted 2.4 million of the precursor cells into 12 sites in the brain.
“The patient is doing well and there have been no major adverse reactions so far,” Takahashi tells Nature. If all goes well, in six months doctors will implant another dose of neurons into the patient’s brain.
In the future, the researchers plan to give the treatment to six other Parkinson’s disease patients.
“The best scenario is to see patients improve to the extent they do not have to take any medicine,” Takahashi tells The Japan Times.