It may be possible to use a patient's own skin to repair the damage caused by multiple sclerosis (MS), which is currently incurable, say researchers.
Nerves struggle to communicate in MS as their insulating covering is attacked by the immune system - causing fatigue and damaging movement.
Animal tests, described in the journal Cell Stem Cell, have now used modified skin cells to repair the insulation. Experts said there was an "urgent need" for such therapies.
Just like electrical wires, nerves have insulation - but instead of plastic, the body uses a protein called myelin.
However, diseases that result in damage to the myelin, including MS, leave the nerves exposed and electrical signals struggle to travel round the body.
A team of scientists at the University of Rochester Medical Center, in the US, used advances in stem-cell research to attempt to repair the myelin.
They took a sample of human skin cells and converted it into stem cells, which are capable of becoming any other type of cell in the body.
The next step was to transform the stem cells into immature versions of cells in the brain that produce myelin.
When these cells had been injected into mice born without any myelin it had had a significant effect, said researchers.
Dr Steven Goldman told the BBC that "myelin was produced throughout the nervous system" and some mice had achieved "normal life spans".
He said: "In MS the underlying nerves fibres are still there, the objective is to re-myelinate them."
However, MS patients would still have the problem of their immune system attacking their myelin.
Any treatment would need to be used alongside other therapies to tame the immune system - or would need to be repeatedly performed.
Dr Goldman said he could see "no reason to be pessimistic" although further safety tests would be needed and the technique still needed to be refined before being used in people. He expects to begin trials within a couple of years.
Dr Emma Gray, from the MS Society, said: "Myelin repair therapies are urgently needed in MS and we're pleased to see researchers have been able to generate myelin making cells from human stem cells.
"This is still very early stage research, but with more development could one day be used to repair damage to myelin in people with MS. We look forward to seeing more research in this promising area."
Source: BBC News