MicroRNA-29a regulates neural stem cell neuronal differentiation by targeting PTEN

Neural stem cells (NSCs) are self-renewing, pluripotent, and undifferentiated cells which have benefits as candidates for central nervous system (CNS) injury. However, the transplanted NSCs usually maintain their undifferentiated characteristics, or differentiated potentially along the glial lineage after transplantation. MicroRNAs (miRNAs) are small, non-coding RNAs that play key roles in cell differentiation. However, it is unknown whether miR-29a could play a role in the process of NSC's differentiation. Primary NSCs were derived from rat embryonic cortex. Lentiviral vector-mediated miR-29a (LV-miR-29a) and negative control (LV-null) were infected into NSCs. Quantitative real-time PCR was used to detect expression of miR-29a and PTEN. Immunocytochemistry was used to stain neurons, astrocytes, and oligodendrocytes. Dual luciferase assay to study the interaction between miR-29a and PTEN. The current study showed that the expression of miR-29a was upregulated during NSC differentiation, while the expression of PTEN was downregulated during NSC differentiation. After infection with LV-miR-29a, MAP-2-positive neurons significantly increased, and GFAP-positive astrocytes significantly decreased. Furthermore, we demonstrated that PTEN is a molecular target of miR-29a. miR-29a promote the neuronal differentiation and decrease the astrocytes differentiation of NSCs via targeting PTEN. This may give insight into a novel mechanism of NSC differentiation and provide a promising therapeutic target.