Direct Generation of Human Neuronal Cells from Adult Astrocytes by Small Molecules

Astrocytes, due to the proximity to neuronal lineage and capability to proliferate, are ideal starting cells to regenerate neurons. Human fetal astrocytes have been successfully converted into neuronal cells by small molecules, which offer a broader range of further applications than transcription factor-mediated neuronal reprogramming. Here we report human adult astrocytes could also be converted into neuronal cells by a different set with fewer small molecules. These induced neuronal cells exhibited typical neuronal morphologies, expressed neuronal markers, and displayed neuronal electrophysiological properties. Genome-wide RNA-sequencing analysis showed the gene expression profile of induced neuronal cells resembled that of human embryonic stem cell-differentiated neurons. When transplanted into postnatal mouse brains, these induced neuronal cells could survive in vivo. Altogether, our study provides a new strategy to directly generate transgene-free neurons from human adult astrocytes by small molecules.