An advance that led to the creation of new neurons in mice could be used to transplant brain cells in Parkinson’s patients and cure them of the disease.
Researchers at the University of California, San Diego School of Medicine created neurons in mice using a new and much simpler method that involved gene rewriting.
Parkinson’s disease is characterized by a loss of dopaminergic neurons in a region of the brain responsible for reward and movement; replacing those cells could help reduce or even reverse the symptoms of degenerative disease.
A small study involving Parkinson’s mice found that those who received the “new neuron treatment” returned to normal within three months and remained disease-free for life.
The researchers said that one day it could be used to “cure” any disease caused by the loss of neurons, but they cautioned that this was a long way off and had not been proven.
Left: Mouse cells (green) before reprogramming, and then right shows neurons (red) induced by mouse cells after reprogramming. Researchers at the University of California, San Diego School of Medicine created these neurons in mice using a much simpler new method
Parkinson’s disease is characterized by a loss of dopaminergic neurons in a region of the brain responsible for reward and movement; replacing those cells could help reduce or even reverse the symptoms of degenerative disease
Xiang-Dong Fu and his team say their findings suggest that certain brain cells called astrocytes can become functional dopaminergic neurons.
It is early in the research, but these newly produced brain cells could one day be implanted in a Parkinson’s patient to help his condition.
“It is my dream to see this through clinical trials, to test this approach as a treatment for Parkinson’s disease, but also for many other diseases where neurons are lost, such as Alzheimer’s and Huntington’s disease and strokes.” .
The study published in Nature was carried out on isolated human cells and mice.
“Researchers around the world have tried many ways to generate neurons in the laboratory, using stem cells and other means, so that we can study them better, as well as use them to replace neurons lost in neurodegenerative diseases,” said Dr. Fu .
“The fact that we could produce so many neurons relatively easily was a big surprise,” said the lead author of the article.
Astrocytes produce a protein that prevents them from becoming neurons, but by removing this protein they become fully functional neurons.
As part of this study, the team discovered that new neurons can repopulate circuits in the brain, restore dopamine levels, and rescue motor function in Parkinson’s mice.
But they caution that more research is needed before the approach can be applied to humans, as it has only been studied in the brains of mice.
The researchers administered the treatment directly to a part of the mouse brain, which is responsible for regulating motor control and reward behavior.
They also added it to the part of the brain that generally loses dopamine-producing neurons in Parkinson’s disease.
A control group of mice received sham treatment without new neurons.
Above: mouse brain before reprogramming, with green dopaminergic neurons. Bottom: mouse brain after reprogramming with PTB antisense oligonucleotide treatment, which converted astrocytes to more dopaminergic neurons (green)
In treated mice, a small subset of astrocytes converted to neurons, increasing the number of neurons by about 30 percent, the study suggests.
Dopamine levels were restored to a level comparable to that of normal mice.
Using two different measures of limb movement and response, the treated mice returned to normal within three months of a single treatment.
They remained completely free of Parkinson’s disease symptoms for the rest of their lives, but the control group showed no improvement.
Professor Tara Spiers-Jones from the UK Dementia Research Institute at the University of Edinburgh and deputy director of the University of Edinburgh Brain Discovery Science Center, said the study shows remarkable promise.
“It is important to note that it was done in mice with size groups of three to eight and there is a long way to go to translate this into a treatment for people.”
Robert Howard, a professor of psychiatry in old age at University College London, said the findings were an “extraordinary scientific discovery.”
He added: “This opens up a whole new avenue for developing treatments to” rebuild “damaged brains in Alzheimer’s and Parkinson’s diseases.”
The findings have been published in the journal Nature.