A personalized treatment for multiple sclerosis may be one step closer, thanks to a new study that reveals how a person's own skin cells could be used to repair the nerve damage that the disease causes.
These "induced neural stem cells" (iNSCs) were transplanted into the rodents' cerebrospinal fluid.
Lead study author Dr. Stefano Pluchino, of the Department of Clinical Neurosciences at the University of Cambridge, and team believe that their strategy could offer a promising treatment for MS and other neurological diseases.
The researchers recently reported their findings in the journal Cell Stem Cell.
MS is a progressive neurological disease that is estimated to affect more than 2.3 million people across the globe.
While the precise causes of MS remain unclear, "an abnormal immune system response" is thought to be involved. Such a response leads to inflammation in the CNS, which causes the destruction of myelin, or the fatty substance that protects nerve fibers.
As a result, the nerve fibers become damaged. This disrupts neuronal signaling and triggers the neurological symptoms of MS, including tingling in the face or extremities and problems with movement, balance, and coordination.
Using stem cells to treat MS
Previous research has investigated the use of NSCs for the treatment of MS. NSCs are stem cells that have the ability to transform into different types of cell in the CNS — including neurons and glial cells.
However, there are some barriers to this strategy. As Dr. Pluchino and colleagues note, NSCs are derived from embryos, and it would be hard to obtain them in high enough quantities to sustain clinical treatment.
It is also possible that the immune system would see embryo-derived NSCs as foreign invaders and try to destroy them.
As such, researchers have turned their attention toward iNSCs, or NSCs that can be developed by reprogramming adult skin cells. Importantly, since these cells would be derived from the patients themselves, the risk of an immune system attack would be significantly reduced.
To test whether iNSCs could be a feasible treatment option for MS, Dr. Pluchino and his colleagues tested them on adult mice that had been genetically engineered to develop the condition.
The team took cells from the skin of the mice and reprogramed them into NSCs, effectively making iNSCs. Next, the team transplanted these iNSCs into the cerebrospinal fluid of the mice.
Study yields promising findings
The researchers found that this led to a reduction in levels of succinate, which is a metabolite that the team found is increased in MS. This increase prompts microglia — a type of glial cell found in the CNS — to trigger inflammation and cause nerve damage.
By reducing succinate levels, the iNSCs reprogrammed the microglia — which, in turn, reduced inflammation and brain and spinal cord damage in the mice.
Of course, human clinical trials are needed before iNSCs can be considered as a suitable treatment for MS, but this latest study certainly shows promise.
"Our mouse study suggests that using a patient's reprogrammed cells could provide a route to personalized treatment of chronic inflammatory diseases, including progressive forms of MS."
Dr. Stefano Pluchino
"This is particularly promising," Dr. Pluchino adds, "as these cells should be more readily obtainable than conventional neural stem cells and would not carry the risk of an adverse immune response."