Circulating microRNAs in the cerebrospinal fluid of patients with brain diseases.

MicroRNAs (miRNAs) are small, noncoding regulatory RNAs that regulate gene expression at the -posttranscriptional level. Although circulating miRNAs in human body fluids have recently been recognized as disease biomarkers, especially in the field of oncology, little is known about the miRNAs in cerebrospinal fluid (CSF). This chapter describes the feasibility of miRNAs in CSF as biomarkers for the diagnosis of brain diseases and the methods of miRNA isolation from CSF.