Stem cell first for Parkinson's

Note: there is a wonderful photo of the stem cell in the article

BBC News
http://news.bbc.co.uk/go/pr/fr/-/1/h...th/6742163.stm
Published: 2007/06/12 09:18:08 GMT

US researchers have for the first time injected human stem cells into monkeys with Parkinson's symptoms, seen as a key step in the fight to find a cure.

The stem cells, which have been injected into rodents in the past, initially stopped the monkeys' damaged brain cells from deteriorating.

The primates' condition did however start to slide after four months, the study in the PNAS journal said.

Stem cells offer great hope for cures, but a breakthrough remains elusive.

"We are still talking about years," said Dr Richard Sidman, one of the co-authors of the study. "But it's a start, and we may be looking at applications for a number of diseases other than Parkinson's."

Primates v people

It surprised the team that the stem cells - rather than replacing the damaged cells as anticipated - actually worked to protect them, preventing further deterioration.

But while the monkeys fared well in the initial months of the trial, four months in they started once again to show the symptoms of the disease.
The researchers speculate this may be to do with the monkeys beginning to reject foreign tissue, and suggested that further research would need to be done suppressing their immune systems.

Dr Kieran Breen, Director of Research and Development for the Parkinson's Disease Society, urged caution.

"These results are from a very early stage pre-clinical trial using an animal model of Parkinson's," he said.

"Further trials are needed to establish whether similar results are seen in people who have Parkinson's."

Dr Stephen Minger, Director of King's Stem Cell Biology Laboratory, said he welcomed any research which took the search for a cure further but similarly cautioned against great hopes.

Master cells

More than four million people worldwide are estimated to suffer from Parkinson's disease, making it the most common brain degenerative disease after Alzheimer's disease.

It is a disease of the nervous system that generally affects both men and women who are more than 40 years old. It is associated with trembling of the arms and legs, stiffness and rigidity of the muscles and slowness of movement.

The progressive decline brought on by the condition is caused by a loss of brain cells which produce a chemical called dopamine.

Stem cells are seen as providing one of the major avenues of hope for a cure.

The body's "master cells", stem cells are created shortly after conception. They have the capacity to turn into any kind of tissue in the body.
Story from BBC NEWS:

Neural stem cells reduce Parkinson's symptoms in monkeys

Public release date: 12-Jun-2007
Yale University
http://www.eurekalert.org/pub_releas...-nsc061207.php

New Haven, Conn.—Primates with severe Parkinson’s disease were able to walk, move, and eat better, and had diminished tremors after being injected with human neural stem cells, a research team from Yale, Harvard, the University of Colorado, and the Burnham Institute report today in Proceedings of the National Academy of Sciences.

These results are promising, but it will be years before it is known whether a similar procedure would have therapeutic value for humans, said the lead author, D. Eugene Redmond Jr., professor of psychiatry and neurosurgery at Yale.

“Not only are stem cells a potential source of replacement cells, they also seem to have a whole variety of effects that normalize other abnormalities,” Redmond said. “The human neural stem cells implanted into the primates survived, migrated, and had a functional impact. It’s an important step, but there are a number of studies that need to be done before determining if this would be of any value in clinical settings.”

Parkinson’s disease is caused by a degeneration of dopamine neurons in an area of the midbrain known as the substantia nigra, which is responsible for dopamine production. Reduced production of dopamine in late stage Parkinson’s causes symptoms such as severe difficulty in walking, fewer movements, delays in moving, lack of appetite, difficulty eating, periods of remaining motionless known as “freezing,” and head and limb tremors.

In this study five of eight monkeys with advanced Parkinson’s were injected with human neural stem cells and three received sham injections. The monkeys were observed four months before and four months after surgery. Those injected with human neural stem cells improved progressively for the entire post-treatment period and were significantly different from the monkeys that received sham injections. Twenty-one additional monkeys were studied for up to eight months for other biological effects of the stem cells. No tumors or toxic effects were found.

Redmond said a small number of the human neural stem cell progeny differentiated into neurons that contained tyrosine hydroxylase and dopamine transporter. Cell progeny containing these markers suggest that the microenvironment within and around the brain lesions still permits development of a dopamine phenotype by responsive progenitor cells. The stem cells also made a growth factor that has been shown to improve dopamine function.

The neural stem cells are derived from fetal brain and are not embryonic stem cells. Monkeys with “chimeric” human neural cell-bearing brain regions showed no indication of behaviors that were not typical of the species.

go Hard ......science

Where did they get the human fetal brain? The idea of it is disturbing to me.

From Nature online:

" In the current study, published in Proceedings of the National Academy of Sciences1, researchers isolated stem cells from the brains of aborted fetuses and grew them into large numbers in the laboratory. The cells were then injected into the brains of monkeys with a severe form of chemically induced Parkinson's disease."

http://www.nature.com/news/2007/0706.../070611-2.html

I don't know if everyone has access to this article. Please let me know if you don't.

I don't know how I feel about using neural cells from 13 week old fetuses, even if they were miscarried. I guess it's like any organ donation, but somehow this seems different, maybe because it's brain cells implanted into a primate, almost like part of the embryo lives on in the primate, which seems creepy. And one article says miscarriage and another says abortion. I don't like the idea of killing an embryo and then someone using the brain for research by injecting part of it into a primate. Maybe because I feel that my identity is tied totally to my brain cells.

NewScientist.com

Human stem cells treat Parkinson's in monkeys

* 22:00 11 June 2007
* NewScientist.com news service
* Andy Coghlan

A single injection of neural stem cells has markedly improved the symptoms of Parkinson's disease in monkeys, paving the way for stem-cell therapies in humans with the condition.

Richard Sidman at the Harvard Institutes of Medicine in Boston, US, and colleagues recreated the symptoms of Parkinson's in African green monkeys by injecting them with a chemical that damages neurons that make dopamine – a neurotransmitter vital for controlling movement.

They then injected the monkeys' brains with neural stem cells taken from human fetuses that had been miscarried at 13 weeks. A month later, the monkeys showed marked recoveries.

"They could stand, walk, feed themselves, and had regained independent living," says Sidman.
Temporary benefits

After around four months, the animals again began to deteriorate, probably because the stem cells were being attacked by the monkeys' immune systems. However, they were still much healthier than untreated monkeys.

Post-mortems showed that the implanted cells had dispersed throughout the brain to structures where dopamine is produced. Their primary role seemed to be in protecting the brain against further damage, rather than replacing damaged cells, as had previously been assumed.

The team now plans to see if immunosuppressive drugs and repeat injections can prolong the benefits over the longer term.

Journal reference: Proceedings of the National Academy of Sciences (DOI: 10.1073/pnas.0704091104)

Fetus at 12 weeks: fair warning:

http://www.nlm.nih.gov/medlineplus/e...pages/9572.htm

Dear Zucchiniflower,
I think what they may have meant was the proper term for a miscarriage which is a spontaneous abortion.
Regards,
Lee

Thank you, Lee. I hadn't heard of that term.