altering immune-related gene levels in MS by targeting regulatory microRNAs

Members of the Australia and New Zealand MS Genetics Consortium (ANZgene) compared miRNA patterns in blood samples from 59 MS patients and 37 healthy controls (PLoS ONE link soon to come). Two specific microRNAs, miR-17 and miR-20a, have been found at significantly lower levels in the blood of MS patients (RR-MS, PP-MS and SP-MS) than in that of unaffected individuals. Both of these miRNAs are thought to regulate immune genes in humans by curbing the expression of genes involved in T-cell activation in the immune system. Therefore, these miRNAs could be very useful in the development of novel MS treatments.

Other than recent usage of miRNA technologies, MS research has focused a lot on HLA-loci and epigenetic factors associated with MS incidence. However, it seems as though miRNA associations could be much more helpful in understanding more about MS development and therapeutic approaches. Results from the aforementioned study suggest that miR-17 and miR-20a down-regulation is linked to enhanced mRNA levels for some of the same T-cell related genes that get over-expressed in MS patient blood samples, leading us to believe that the miRNAs contribute to MS development.

The ANZgene team concluded that:

Even if the miRNAs under-expressed in MS were not directly contributing to the immune cell signature observed in MS whole blood, the excessive T-cell activation signature seen in MS and other autoimmune diseases suggest agents which can reduce this activity may be therapeutically beneficial.

Whether or not the miRNAs contribute directly to the disease, it might be possible to target these kinds of regulatory miRNAs and therefore tweak immune related gene levels in MS.