A comprehensive, cell specific microRNA catalogue of human peripheral blood

MicroRNAs (miRNAs) are small noncoding regulatory RNAs, which are involved in complex regulatory processes including inhibition of translation and modulation of transcript stability. These molecules are implicated in the pathogenesis of oncological, immune-related, cardiac and other diseases. The discovery of circulating miRNAs in serum, plasma, and other body fluids has attracted great interest in biomarker research. To date, numerous studies have reported circulating miRNAs as biomarkers for a variety of diseases. However, the origin of these circulating miRNAs has been poorly examined. With this study, we provide a comprehensive reference dataset of detailed miRNA expression profiles from seven types of human peripheral blood cells, serum, exosomes and whole blood. The peripheral blood cells from buffy coats were typed and sorted using FACS/MACS. The overall dataset was generated from 450 small RNA libraries using high-throughput sequencing. We define the cell lineage-specific miRNA/isomiR expression and modification patterns. Furthermore, we identify novel cell-type specific miRNA candidates. The study provides the most comprehensive contribution to date towards a complete miRNA catalogue of human peripheral blood, which can be used as a reference for future studies.