MicroRNAs in oligodendrocyte and Schwann cell differentiation.

MicroRNAs (miRNAs) are a class of small (approx. 22 nt) noncoding RNAs that are capable of post-transcriptionally silencing mRNAs that contain sequences complementary to the miRNAs' 7- to 8-bp 'seed' sequence. As single miRNAs are often predicted to target up to hundreds of individual transcripts, miRNAs are able to broadly affect the overall protein expression state of the cell. This can translate into global effects on cellular health and differentiation state. Recently, several reports have identified crucial roles for miRNAs in controlling the production, differentiation, and health of myelinating cells of the mammalian nervous system. In this review, we will discuss how individual miRNAs regulate these various processes, and also how miRNA production in general is required for several stages of myelin generation and maintenance.