New Findings on Multiple Sclerosis
Blood vessel in the brain of a healthy person (top) and a patient with Multiple Sclerosis (at the bottom). Shown in blue are the cell nuclei, in red the potassium channels TREK-1, and in green the endothelial cells, that line the small blood vessels. The channel nearly lacks in patients. (Picture: Stefan Bittner)
Aggressive immune cells can intrude into the brain via a previously unknown channel. This has been reported by researchers from Münster and Würzburg in the journal "Nature Medicine". Their discovery opens up new prospects for the treatment of multiple sclerosis.
In Germany alone, about 130,000 people suffer from multiple sclerosis (MS). The disease usually begins between the ages of 20 and 40 and includes episodes of sudden worsening: The immune system gradually destroys the insulating layer surrounding the nerve fibers in the brain and in the spinal cord.
In the early stages of the disease, those affected often report a tingling sensation in their arms and legs. They tend to trip more often or experience visual problems. In serious cases, the disease can lead to severe disabilities at a later stage; some patients will then require a wheelchair. At present, the disease cannot yet be cured, only mitigated.
How is the disease process described today? Professor Christoph Kleinschnitz, one of the lead scientists of the clinical research group for multiple sclerosis at the University of Würzburg, explains: "At first, the harmful immune cells are erroneously activated. They then penetrate the blood–brain barrier, which is supposed to prevent them from entering the brain under normal conditions. Finally, they cause inflammations in the brain and in the spinal cord."
Potassium channel as a new target
The immune cells apparently require a previously unknown channel for entry into the brain as reported in "Nature Medicine" by Kleinschnitz and his colleagues of the University of Münster. This channel (TREK-1) is located in the cells lining the small blood vessels and it is usually responsible for getting potassium ions out of the cells into the blood.
However, the channel also enables the harmful immune cells to attach themselves to the vessel wall, through which they penetrate into the brain. The researchers have now successfully disrupted this very process in several animal models. The result: The symptoms of multiple sclerosis were attenuated.
The next objective: more effective drugs
Next, the scientists are going to develop new agents that target these channels more specifically and effectively. Dr. Stefan Bittner and Professor Sven Meuth, the two lead authors of the article, feel confident that this study might lead some day to the development of a drug with which the treatment of multiple sclerosis can be further improved. Their hope is justified: The strategy to block immune cell leakage through the blood-brain barrier has proven effective in principle.
Financial support for these studies includes funding by the German Research Foundation via the Würzburg Collaborative Research Center 688 ("Mechanisms and imaging of cell-cell interactions in the cardiovascular system").
"Endothelial TWIK-related potassium channel-1 (TREK1) regulates immune-cell trafficking into the CNS", Stefan Bittner, Tobias Ruck, Michael K Schuhmann, Alexander M Herrmann, Hamid Moha ou Maati, Nicole Bobak, Kerstin Göbel, Friederike Langhauser, David Stegner, Petra Ehling, Marc Borsotto, Hans-Christian Pape, Bernhard Nieswandt, Christoph Kleinschnitz, Catherine Heurteaux, Hans-Joachim Galla, Thomas Budde, Heinz Wiendl & Sven G Meuth. Nature Medicine, 11 August 2013, DOI 10.1038/nm.3303
Contact person
Prof. Dr. Christoph Kleinschnitz, Department of Neurology at the University Hospital of Würzburg, T: +49 (0)931 201-23756, 
christoph.kleinschnitz@uni-wuerzburg.de
12.08.2013, 11:54 Uhr