We spoke with mitochondria expert Dr Don Mahad, from the University of Edinburgh, about what makes them so special - and what goes wrong in MS.
Mitochondria and progressive MS
‘I’m interested in energy production and demand in the brain and spinal cord, and especially how this changes in progressive MS.’ It’s the mitochondria that generate the bulk of this energy.
‘Mitochondria are smaller than the size of a pinhead, yet play a critical role in keeping us healthy’ says Don. ‘The healthy brain makes up just 2% of your body but takes 20% of the energy. To meet this demand, mitochondria station themselves all along the nerve fibres.’
When a cell loses myelin it has to work harder to survive and send signals, so needs more energy. ‘We can see a build-up of mitochondria in MS lesions, to try and meet the extra demand,’ says Don. Mitochondria are made in the cell body, ready to travel down the nerve fibre and replace old or faulty mitochondria.
But Don has found that in MS, this starts to go wrong as well. ‘If you look at a nerve cell in progressive MS, the mitochondria aren’t healthy or working properly. So you end up with a situation where the energy demand is increasing but the ability to supply it is decreasing.’
Tackling the problem
Dr Mahad has got several projects on the go to unravel the mysteries of mitochondria: ‘We are using post-mortem tissue to look deep into the nerve cells and answer questions about what goes wrong with mitchondria transport in progressive MS.
‘As part of the International Progressive MS Alliance, we’ve also developed animal models to see how problems with mitochondria affect symptoms. So far we’ve shown that problems with the mitochondria can cause fatigue and changes to walking.’
When asked why he is so keen to understand mitochondria, Don is clear: ‘Once we know what goes wrong with the mitochondria in progressive MS, we can start developing therapies to fix it.’
This blog first appeared in Research matters magazine. To receive Research Matters by post please contact firstname.lastname@example.org about subscription. You can also download the full issue for free.