Small Molecule Compounds Induce Mouse Embryonic Fibroblasts to Reprogram Into Neural Stem Cells

Stem cell reprogramming has held promise for regenerative medicine since the creation of induced pluripotent stem cell methods. In the field of neuroscience, it has been proved that neural stem cells have strong adaptability, low tumorigenesis risk, and can be used to treat diseases related to the nervous system in a targeted manner. Therefore, it is of great significance to induce neural stem cells for clinical treatment in vitro. Compared with genetic methods, there is growing evidence that small molecule compounds can improve the efficiency of somatic cell reprogramming and are relatively easier to apply, optimize, manufacture, and develop into drugs. In this study, mouse embryonic fibroblasts（MEFs） of 14 days were induced for 12 days by a specific combination of 9 small molecular compounds（M9） without hypoxic conditions. Surface markers of neural stem cells were detected before and after induction and RNA was extracted for transcriptome analysis. The results showed that after induction for 12 days, the cell morphology was spherical similar to that of the primary neural stem cells. The levels of SOX2 and other surface markers of the neural stem cells were up-regulated in immunofluorescence and RT-qPCR. Transcriptome analysis showed that the M9-induced cells had a very similar gene expression profile and self-renewal ability to the primary neural stem cells. In conclusion, M9 can induce MEFs to reprogram into neural stem cells. The significance of this study lies in the use of small molecular compounds to replace transcription factors, and the direct reprogramming of neural stem cells is realized in vitro under simple conditions, avoiding the tumorigenesis risk caused by the introduction of viral transduction vectors, and promoting the research on clinical treatment of neural stem cells.