The study suggests that blocking the proteins that regulate the signal might be an efficient strategy for new therapies against MS for which there is currently no known definitive cure.
However therapies do exist for the MS symptoms such as patients experiencing acute attacks, for patients who have the relapsing-remitting subtype, for patients who have the progressive subtypes, for patients without a diagnosis of MS who have a demyelinating event, and for managing the various consequences of MS attacks.
Treatment is aimed at returning function after an attack, preventing new attacks, and preventing disability.
Italian and German scientists focused their efforts on a key player in the molecular mechanisms behind MS - a signalling molecule called NF-kB.
To get a clear picture of NF-kB's role in MS, Manolis Pasparakis, a former Group Leader at EMBL's Mouse Biology Unit and his scientific collaborators at the University of Göttingen investigated what happens to mice with an MS-like condition if the action of NF-kB is blocked.
To shut down the signal they inactivated IKK2 and NEMO, two proteins that activate NF-kB.
"We have known for a long time that NF-kB is crucially involved in MS," said Pasparakis, a former Group Leader at EMBL's Mouse Biology Unit who now works as a Professor at the Institute for Genetics at the University of Cologne, "but until now it was not clear if it was friend or foe."
"We were not sure whether it protects the brain cells against the consequences of the disease or actually aggravates the damage."
The results were mice that showed much milder MS symptoms than normal, an effect that is very likely to be linked to the lower amount of inflammatory messengers produced by their brain cells.
"This was quite a challenge because NF-kB is involved in many crucial processes throughout the entire body, and shutting down its activation in all cells kills the mouse before it is born," says Pasparakis,
"To observe the effect of NF-kB in MS, we used sophisticated genetic techniques to generate mice that do not express IKK2 and NEMO in brain cells only."
Scientists continue in their efforts to create new and better therapies for MS. One of the most promising MS research areas involves naturally occurring antiviral proteins known as interferons.
Beta interferon has been shown to reduce the number of exacerbations and may slow the progression of physical disability. When attacks do occur, they tend to be shorter and less severe. In addition, there are a number of treatments under investigation that may curtail attacks or improve function.
Over a dozen clinical trials testing potential therapies are underway, and additional new treatments are being devised and tested in animal models.
"NF-kB regulates the production of messengers that are released during inflammation to recruit and activate immune cells," said Marco Prinz, whose group at the University of Göttingen collaborated in the research.
"Generally this is a good strategy to protect the body from infections. But in MS it is exactly these immune cells that cause the problem and their hyperactivation through NF-kB only makes the situation worse."
Blocking IKK2 and NEMO interfered with this pathological action of NF-kB and alleviated the symptoms of MS.
This makes the proteins promising as potential drug targets for new therapies against the disease.
The human NF-kB signaling network is very similar to that of mice, so that compounds that inhibit IKK2 and NEMO are likely to lead to the same alleviation of symptoms in humans.