Molecular characterization of human osteoblast-derived extracellular vesicle mRNA using next-generation sequencing

In this study, we present the comparative transcriptome analysis of human osteoblasts and their corresponding EVs using next-generation sequencing. We demonstrate that osteoblast-EVs are specifically depleted of cellular mRNAs that encode proteins involved in basic cellular activities, such as cytoskeletal functions, cell survival and apoptosis. In contrast, EVs are significantly enriched with 254 mRNAs that are associated with protein translation and RNA processing. Moreover, mRNAs enriched in EVs encode proteins important for communication with the surrounding cells, in particular with osteoclasts, adipocytes and hematopoietic stem cells. Strikingly, EVs are particularly enriched with RAB13 mRNA, which is linked to vesicular trafficking. The latter suggests that EVs may affect vesicle production in target cells. These findings provide the foundation for understanding the molecular mechanism and function of EV-mediated interactions between osteoblasts and the surrounding bone microenvironment. Overall design: Simian virus 40-immortalized human osteoblast cells (SV-HFO cells) were cultured for fourteen days and EV isolated. Total and EV RNA was isolated using TRIzol reagent, and mRNA/miRNA-Seq was performed as described.