Neurons derived from artificial stem cells reduce symptoms of Parkinson’s disease.


Neurons grown from embryonic stem cells; yellow colored nerve cells that synthesize dopamine. (Photo: California Institute for Regenerative Medicine / Flickr.com.)

Progenitor cells of motor neurons (colored green). (Photo: California Institute for Regenerative Medicine / Flickr.com.)

Neurons grown from embryonic stem cells; yellow colored nerve cells that synthesize dopamine. (Photo: California Institute for Regenerative Medicine / Flickr.com.)

Progenitor cells of motor neurons (colored green). (Photo: California Institute for Regenerative Medicine / Flickr.com.)”

Whenever we talk about stem cells, referred to be sure about their medical prospects. As we know, stem cells can turn into any other cell type, and with their help, it would be quite possible to compensate for cell losses that occur when injuries, diseases, etc .

Famous neurodegenerative diseases (Alzheimer’s, Parkinson’s, etc.) linked to a massive loss of neurons in the brain. Once the stem cells turn into anything, therefore, in neurons, too. Can I use cell-stem methods to add the brain nerve cells to replace those killed?

There is one very important point – the new neuron because it is not enough just to stick in the brain, it needs to establish contacts with other nerve cells, involved in the neural chain that handle certain information. Whether the transplanted neuron to do all this? Actually maybe a year ago we wrote about the experiments in which the neurons derived from stem cells transplanted in mice brain, the visual cortex is transplanted crates have established the right contacts with “local”, so that the vision in mice even improved.

Researchers from the Kyoto University did something similar with monkeys, only this time it was about to put it in the brain neurons in different varieties – those that are primarily killed during Parkinsonian syndrome.

For this purpose, the artificial stem cells, which are derived from a Mature, specialized cells of the body have seven people (three with Parkinson’s disease and four healthy) took samples of blood and skin and then use a special protein cocktail did reprogram skin and blood cells so that they have lost specialization, forgot her functions, and returned, say so in childhood.

The thus obtained induced pluripotent stem cells, as these stem cells from the embryo are able to share extremely long, so they could build in the right amount, and then, with the help of other proteins-regulators send to neural development.

Neurons, as we said, needed not any, and those that synthesize dopamine and work in the motor centers of the brain (Parkinson’s disease is known to impact primarily on coordination).

Cells when spetsializiruyutsya pass through several stages. The researchers waited for the stem cells up to a certain point will advance in their transformations in the nerve cells, and then transplanted them into the brains of macaques-Griboedov, where cells eventually become Mature neurons of the motor cortex.

Monkeys before cellular transplantation has introduced a special neurotoxin, which kills motor neurons in the brain, so the monkeys started with symptoms similar to the symptoms of Parkinson’s disease. But after they in the brain new cells as the monkeys improved by 40-50%: thus, the characteristic tremor of the limbs have been not as strong as before, animal movements become more natural.

The therapeutic effect is long-lasting, it lasted at least a year. That is, the transplanted cells successfully matured to the dopamine neurons, they were able to join in the work of a nervous chain – although, as the researchers write in an article in Nature, such neurons compared to natural cells synthesized only half of the dopamine that should have been. (Perhaps if the cells to replace managed to get them to give more dopamine, and the therapeutic effect would be stronger.)

It is worth mentioning that the cellular raw materials for the experiments were taken from people with Parkinson’s, however, no problems with these cells arose. Even if the causes of the disease in people was genetic – and that means that the corresponding defective genes were in all cells of the body – that they still did not show nor after the transformation into stem cells and then into neurons or after transplantation in monkey brain.

And yet, if we talk about the future clinical perspectives, it is desirable all the same sick person to transplant cells obtained from a healthy donor. And then there is a problem with the immune system, which attack foreign cells.

There are some tricks that are described in a parallel article in Nature Communications. Immune cells distinguish friend from foe on special molecules on the cell membrane, and choosing a donor, you should try to find such that membrane molecules on the cells was similar to that of membrane molecules on cells of the patient.

As shown by experiments in the same monkeys, it really allows to some extent to arouse the vigilance of the immune system. However, although there is still have to perform a lot of research on the safety and reliability of the method, it is important that stem cell-an approach that can help in the case of specific diseases of the nervous system.