Global transcriptional analysis of mouse fibroblasts, chemically-induced neurons (neuron-like cells) from mouse fibroblasts and mouse primary cortical neurons by RNA-seq

Recently, direct reprogramming between divergent lineages has been achieved by introducing cell-fate-determining transcription factors. This progress may provide alternative cell resources for drug discovery and regenerative medicine. However, the genetic manipulation may limit the future application of these approaches. In this study, we identified a novel small-molecule cocktail that directly converted fibroblasts into neuronal cell fate with a high yield up after 16-days of induction. After a further maturation stage, these chemically-induced neurons (CiNs) possessed neuron-specific expression patterns, generated action potentials and formed functional synapses. Gene expression profiling revealed the activation of neuronal specific genes in the early stage of small molecule treatment. Overall, our findings prove the principle of chemically-induced direct reprogramming of somatic cell fates across germ layers without genetic manipulation, and show that cell fate can be manipulated through disrupting initial cell program and activating target cell master genes with pure chemicals.