Parkinson’s disease: stem cells give encouraging results

Photo Fotolia

AFP

Wednesday, 30 August, 2017 13:18

UPDATE
Wednesday, 30 August, 2017 13:18

Look at this article

Stem cells of human origin have improved the capacity of the movements of the monkeys with a form of Parkinson’s, according to a study “promising” to be published Wednesday.

To restore this capacity of movement, impaired in this disease, the researchers reprogrammed adult cells human pluripotent stem cells “iPSC” (for “Induced pluripotent stem cells”) in order to make them able to give a range of different cells, in the case of dopaminergic neurons.

The disease is marked by degeneration of these neurons that produce dopamine, a neurotransmitter involved in the control of motor skills, and leads to symptoms that become progressively worse, such as tremors, rigidity of limbs and decreased body movements.

It affects more than ten million people in the world, according to the Parkinson’s Disease Foundation in the usa.

The survival of the grafted cells by injection in the primate brain, has been observed for two years, without any appearance of tumor.

“The monkeys have become more active, move more quickly and more easily. Their spontaneous movements were increased,” explains Jun Takahashi of the Kyoto university (Japan), co-signer of the article published in the scientific journal Nature.

“I hope we can start a clinical trial by the end of 2018,” he says to the AFP, but before it will still be necessary to “confirm the effectiveness and safety of cells used.

In experiments with fetal cells, the transplanted cells have survived more than 10 years, or 20 years in the brain of patients, noted Dr. Takahashi. Neurons derived from cells iPSC should survive so long, without the need for injections repetitive, after him.

The main treatment of the disease is based on drugs mimicking the action of dopamine that is missing in the brain (levodopa or L-dopa), but that can, over time, cause significant side effects, such as abnormal involuntary movements, and also lose their effectiveness.

In this “looking extremely promising”, the use of stem cells derived from adult cells (iPSC) to human instead of human embryonic stem cells (hESC) means that any country in the world will be able to use this therapy, says Dr Tilo Kunath Centre for regenerative medicine, MRC, University of Edinburgh.

Some countries, such as Ireland and most of South America, have banned the use of embryonic stem cells to perform treatments, says the researcher.

In another article, in Nature Communications, Mr. Takahashi and his colleagues present an approach that improves the survival of neurons derived from iPSC after transplantation using the characteristics of the system, called the major histocompatibility complex (MHC), which plays a role in the rejection of transplants.

This can improve the compatibility between the donor and the recipient without completely eliminating the rejection reactions. The authors suggest, therefore, to accompany this transplantation of an immunosuppressive regimen at reduced doses.