July 21, 2009

When a new protein molecule is made in the body, a sequence of DNA is copied into a messenger RNA molecule, and that mRNA molecule's sequence is then translated into a string of amino acids that become that protein molecule. How much of a particular protein is made at any time often depends on current conditions inside the body, and the production process is controlled with various mechanisms. One of these control mechanisms involves a form of RNA called microRNA, or miRNA for short. miRNAs are also copied from DNA, and they can bind to certain mRNAs and prevent them from being translated into proteins. miRNAs may regulate around 30% of all mRNAs, including those affect inflammation and immune cell function. The over- or underproduction of different miRNAs has been associated with cancer and other diseases, so perhaps they play a role in MS as well.

The first paper to investigate that possibility has now been published in the open-access journal PLOS. This study measured the levels of different miRNA molecules in white blood cells of people with MS (both in relapse and in remission) and in healthy controls. Comparing the levels of the different miRNAs revealed a few that were associated either with MS relapses or MS remissions. The researchers also explored the function of the mRNAs that these miRNAs will bind to, and found functions such as interleukin signaling that would plausibly be involved in MS.

These results indicate that there is some potential for miRNAs to be used as biomarkers for MS and provide more information about the mechanisms of this disease.