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njecting neurons created from stem cells into the brain may relieve Parkinson’s symptoms, according to a new study in monkeys.

Why it matters:

Parkinson’s disease can happen when some of a person’s dopamine-producing brain cells die, so replacing those neurons could be an effective treatment. Administering dopamine is part of currently accepted treatment, but over time the treatment has less effect as neurons die off and the side effects become difficult to manage. So scientists have begun studying approaches using stem cells, primarily in rodents. A clinical trial is also underway at the Royal Melbourne Hospital to inject neural stem cells into the brains of people with Parkinson’s as part of a Phase I clinical trial. Results are expected in 2019, and preliminary results were presented at the American Academy of Neurology meeting this year.

The nitty-gritty:

Researchers collected skin or blood cells from seven humans, some who had Parkinson’s disease and some who did not. (The people with Parkinson’s did not have any of the genes thought to be associated with the disease.) Next, using sets of proteins, they “reprogrammed” some of those cells and encouraged them to grow up as neurons — specifically, neurons that could produce dopamine. Finally, they injected the stem cells into the brains of monkeys that were treated with a neurotoxin, which made them act like they had the condition.

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Researchers found that the symptoms of the monkeys treated with stem cells from either group improved more over the course of a year than monkeys treated with a placebo injection. To determine if the monkey’s symptoms had improved, the team evaluated their tremors, movements, and posture, among other things. The team published its results in Nature on Wednesday.

“I think that a stem cell-based therapy will bring more benefits than conventional treatments can do now,” said Dr. Jun Takahashi, a professor at Kyoto University and one of the authors of the paper.

You should know:

Among conventional treatments for Parkinson’s is a medication called L-DOPA, which ultimately helps patients replace some of the dopamine they can no longer produce. Another accepted procedure is deep brain stimulation, which sparked Takahashi’s interest in this project, he said.

Takahashi and his team did not run tests comparing their results to those seen after deep-brain stimulation and L-DOPA treatment, but they did compare their findings to published statistics. They concluded that the transplants “should exert [similar] effects.”

What they’re saying:

Dr. Lorenz Studer, director of the center for stem cell biology at Memorial Sloan Kettering Cancer Center, said Takahashi’s work was “a very impressive study,” especially given the number of animals, the length of time they were followed, and the similarity of the protocols used to those that might be used in human trials. “In this regard, it was a really interesting test run,” he said.

“It is probably the best study to date using the induced pluripotent stem cells,” said Studer, who was not involved in the research.

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But keep in mind:

The study isn’t without limitations. Studer noted that the volume of neurons that survived varied widely between monkeys, with no clear behavioral impact. Additional, he said that this paper didn’t particularly characterize cells that were not dopamine-producing. “Whatever they are, they didn’t really cause any problems,” he said. “In the clinic, that’s kind of important to know.”

And more research should also be done to figure out how to identify cell lines that would work best in this kind of treatment, the paper noted.

Takahashi said he plans to start clinical trials in 2018.

The bottom line:

This study adds more convincing animal evidence of the promise of stem cells in treating Parkinson’s disease, and human trials may soon give an even clearer picture.

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  • I am a 77-year-old lady. My Parkinson’s disease appeared at the age of 55. My symptoms at the beginning were fine tremors and rigidity with joint stiffness. I was taking Entacapone with Levodopa, Carbidopa, and Pramipexole. My Parkinson’s disease was not under control. I lost touch with reality.I searched for alternative treatments and and started on Parkinson’s herbal formula i ordered from Health Herbal Clinic, Just 7 weeks into the Herbal formula treatment i had great improvements with my slurred speech, there is no case of Rigid muscles and Slowed movement (bradykinesia) since treatment, and my tremors completely gone, visit Health Herbal Clinic official website on This treatment is incredible!

  • Excellent article Kate. Keeping in view of the fast progress that we are making in the regenerative medicine, days are not far when we will be able to treat incurable diseases other than Parkinsonism InshaAllah.

  • O comentário de Eliseo Martinez parece muito pertinente.
    Quanto ao estudo, primeiro gostaria de dizer ter comentado no Medscape , sobre trabalhos em geral relacionados à Doença de Parkinson, que estava na hora de voltar a focar no que a Doença realmente é : Diminuição dos níveis de Dopamina na substancia Nigra .
    Quanto à injeção de células pluripotenciais ou modificadas ou próprias da Substancia Nigra , um dos alertas que se deve saber e pesquisar consiste na possibilidade de gerar rejeição local às células tão somente ou a todo grupamento ( regional massive attack) , um tumor, uma tumoração ou uma diferenciação celular em algum tempo após a injeção celular de neurônios dopaminérgicos funcionantes.
    O que diminuiria este potencial perigo talvez , repito, talvez seja o uso de células dos próprios pacientes.
    A outra caracteristica a ser avaliada seriam as vias dopaminérgicas, até porque possivelmente no principio, algumas células locais da substancia nigra devem aumentar sua produção para suprir a deficiencia das que estão falhando .
    E as vias devem ter de diminuir a velocidade de transmissão ou talvez sinalizar para o potencial perigo de um desquilíbrio ente Dopamina e ACTH , levando a algum fluxo ainda não muito bem estudado.
    Portanto , uma colocação rápida de suplementaçaõ de Dopamina pode trazer uma alteração ainda não pensada.
    Parabéns pelo estudo ,muito coerente e bem padronizado .
    Uma padronização adicional poderia ocorrer convencionalmente em paralelo examinando pacientes em uso de L-Dopa e os Macacos da experiencia, em todas as fases tanto dos Humanos ( começo ou continuação do tratamento VO ou de adesivos ) e dos Macacos ( primeiros dias e depois sequenciais do implante celular ).
    Padronização dias/horas ( quantos dias versus quantas horas para o efeito da suplementação de L-Dopa começar a fazer efeito ) e estudo a longo prazo , caso algum paciente queira persisitir em só usar medicação.
    O sacrifício dos animais pode ser desnecessário para autópsia ( ao menos sacrificios em tempos próximos ao implantes ), e poucas biopsias exploradoras se fariam necessárias se fossem usadas células em cultura de humanos falecidos ( onde se dosaria o nivel de dopamina na Substancia Nigra e se colocaria a ¨ingesta ¨via suporte similar ao de ingesta VO ou com adesivos de pele , o que os engenheiros biométicos poderiam fazer aos moldes do coração artificial , por exemplo ) e células de macacos e de ratos + cobaias (muito interessante manter estes na experiencia ) no mesmo feitio da máquina biomecanica das célula humanas.
    O mesmo para o implante celular.
    Em resumo , duas redes neuronais com ou sem ligação à máquina de suporte de vida com ingesta tipo VO e Subcutanea humana e de macacos ( para controle de tempo e similaridade metabólica ) e outras duas redes neuronais com celularidade Humana e de Macacos, ratos e cobaias para implante celular de neurônios modificados ( próprios ou não) produtores de Dopamina.
    Este modelo permite observar por periodo mais longo a experiencia .
    A verificação de quantos parâmetros esta experiência suprotaria comportar é de interesse.
    Bom , é só uma sugestão.
    Muita boa sorte .

  • Skip mice and inject these stem cells into primates via olfactory route into brain. Hopefully some might find the hipocampus, area related to Alzheimer’s

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