Comparative Analysis of microRNA Expression Profiles of Exosomes Derived from Normal and Hypoxic Preconditioning Human Neural Stem Cells by Next Generation Sequencing

Stroke recovery is associated with neural stem cell (NSC) development and neurovascular unit reconstruction. The exosome, as an important intercellular player in neurovascular communication, mediates neuro-restorative events by transferring exosomal protein and RNA cargoes. In this study, we explored the role of exosomal microRNAs (miRNAs) in human NSCs (hNSCs), and analyzed the expression profiles of miRNAs in hNSC-derived and hypoxic preconditioning hNSCderived exosomes with the help of next generation sequencing (NGS). The results demonstrated that a certain proportion of miRNAs were differentially expressed in both exosomes. In addition, target gene prediction and Gene Ontology (GO) enrichment analysis showed that these genes were associated with differentialmiRNAs primarily participating in biological processes (regulation of cellular process), cellular component (intracellular membrane-bounded organelle), and molecular function (binding). Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) pathway enrichment data suggested that most of targeted genes involved in PI3K-Akt, Hippo, MAPK, mTOR, and Endocytosis etc. signaling pathways. We identified the interesting and important expressed miRNA and considered that miR-98-3p might be a special hNSC-derived exosomal-miRNA which was significantly downregulated under hypoxic preconditioning. The hNSCs-derived exosomes were capable of modulating gene expression or promoting stroke therapy. We observed that after hypoxic preconditioning, the functions of these exosomes were changed, and exosomal-miRNAs expression profile was different. In summary, our study suggested that hNSC-derived exosomal miRNAs including hypoxic preconditioning exosomal miRNAs provided a new strategy for the diagnosis and treatment of stroke patients.