Researchers in Japan today announced the launch of a clinical trial to treat Parkinson's disease with neurological material derived from induced pluripotent stem cells (iPS Cells), mature cells that have been chemically manipulated development, from which they can theoretically differentiate into any specialized cells of the body.
The investigative team will inject dopaminergic progenitor cells, a cell type that evolves into neurons that produce dopamine, directly into a brain region known to play a key role in neural degeneration associated with Parkinson's disease. Jun Takahashi, a neurosurgeon at Kyoto University's iPS Cell Research and Application Center (CiRA), will work in collaboration with the Kyoto University Hospital.
Parkinson's disease results from the death of specialized cells in the brain that produce the brain neurotransmitter dopamine. A lack of dopamine leads to a decrease in motor skills, resulting in difficulty walking and involuntary tremors. If the disease progresses, it can lead to dementia. The experimental strategy is to derive dopaminergic progenitor cells from iPS cells and to inject them into the putamen, a round structure at the base of the forebrain. Surgeons drill two small holes through the skull of a patient and use a specialized device to inject about 5 million cells.
Studies in animals have shown that the precursors in the body differentiate into dopaminergic neurons and attach themselves to the brain. Takahashi's group reported last year that Parkinson's disease monkey models showed significant improvements two years after the injection of neurons from human iPS cells.
Instead of manufacturing patient-specific iPSCs, CiRA has adopted the strategy to derive iPS stocks from cells from healthy donors with specific cell types that are less likely to cause immune rejection. "By using cell stocks, we can do much faster and more cheaply," said Cirira Director Shinya Yamanaka, who received the 2012 Nobel Prize in Physiology or Medicine for the development of iPS cells, Science in 2017 As an added precaution, patients receive a common immunosuppressant along with the precursors.
Patient recruitment began today at 5:00 pm local time when Kyoto University Hospital published patient recruitment on its website. The team plans to recruit seven patients and follow them two years after the injection.
This is the third human study using Japan-approved iPS cells. The first to use iPS cell retinal cells to replace age-related macular degeneration (AMD) damaged eye tissue was launched in 2014 and is headed by the wife of Masayo Takahashi-Jun Takahashi of the RIKEN Center for Developmental Biology in Kobe. The AMD treatment was originally described as safe, although an adverse event was reported. Earlier this year, a team from the University of Osaka in Japan received conditional approval for an iPS cell-based study of ischemic heart disease.