Japan: Human trial of iPS stem cell Parkinson's disease

Japanese researchers announced on Monday that they will conduct the first human trial of Parkinson's disease with so-called "iPS" stem cells.

A University Research Team Kyoto plans to inject into the brain of patients five million pluripotent stem cells ("iPS") for induced pluripotent stem cells capable of giving any type of cell, the university said in a statement.

These iPS cells from healthy donors will develop into neurons producing dopamine, a neurotransmitter involved in motor control.

The disease is marked by the degeneration of these neurons and results in progressively worsening symptoms such as tremor, limb stiffness and decreased body movement. It affects more than 10 million people worldwide, according to the US Parkinson's Disease Foundation.

Currently available therapies "improve the symptoms without slowing down the progression of the disease," says the foundation

This new research is aimed at reversing the disease. The clinical trial with seven participants aged 50 to 69 will begin Wednesday. The university will monitor the patients' condition for two years.

This trial follows an experiment performed on monkeys with stem cells of human origin that improved the ability of primates with Parkinson's disease to make movements, according to a study published in late August 2017 in the scientific journal Nature. The survival of grafted cells, by injection into the brain of primates, was observed for two years without any tumor appearance.

Induced Pluripotent Stem Cells (iPS) are adult cells that are reduced to an almost embryonic state by re-expressing four genes (normally inactive in adult cells). This genetic manipulation gives them the ability to produce any kind of cells (pluripotency), according to the place of the body where they are then transplanted.

In September 2014, the work of the team of Masayo Takahashi, a professor at the Riken public institute, allowed to implant in the eye of a patient, a 70-year-old woman, a thin film of cells created from iPS cells, themselves derived from adult cells of that person's arm skin. The goal was to treat one of the forms of eye disease called age-related macular degeneration (AMD), the leading cause of blindness in people in the industrialized world, over the age of 55.

The use of iPS cells poses no fundamental ethical problems, unlike stem cells taken from human embryos.