Myelin is a protein that acts as an insulator in the brain’s electrical system. A neuronal cell communicates with other neurons through long arms called axons. The electrical flow inside the axon is insulated with the help of other type of cells called glial cells that produce the insulating protein myelin. In the lack of myelin the electrical signals could not be transmitted between two neurons and neuronal disorders such as MS appear.
The research showed that myelin can be generated from stem cells injected to the brain, restoring the brain’s normal behavior. The research team used transgenic mice named “shiverer mice” that don’t produce myelin at all and as their name suggests suffer from shivering and seizures, and usually die at the age of 18-21 weeks. The cells used to restore the myelin were human glial progenitor cells, a certain type of stem cells that can be differentiated into glial cells able to produce myelin. The treatment included injection of those cells through five different spots to the brain. The results were encouraging.
Some of the treated mice overcame the “shivering” symptoms and lived much longer than untreated mice. In the first 130 days after the treatment the treated mice showed no special behavior, but at the age of 150 days, some of the treated mice survived whereas all of the untreated mice died. The surviving mice had decreased their “shivering” symptoms and it was further showed that normal myelin had been formed in their brain. This is the first time a normal layer of myelin was built inside a living brain.
Some human related neuronal diseases are due to lack of myelin and the treatment described can help cure those disorders. Multiple Sclerosis is an example of a disease caused by loss of myelin in a certain part of the brain. Some rare neuronal disorders that infants are born with also result from a lack of myelin, and most of the children suffering from these conditions die at a young age. Although the research shows only a proof of concept and the treatment’s success rate wasn’t high, it does hint at a possible cure for those diseases. The researchers hope that clinical trials in humans are only a few years away.
TFOT has recently reported a treatment in which human stem cells were used to cure a rat’s heart. Some other uses of stem cells covered by TFOT include a recent research study at MIT which showed the potential of artificial stem cells used to cure Parkinson’s disease as well as a Hadassah University research study which aims to use stem cells to cure MS and ALS.
More information on the Myelin research can be found on Nature’s news page.