Pharmacological Perturbation of Mechanical Contractility Enables Robust Transdifferentiation of Human Fibroblasts into Neurons.

Direct cell reprogramming, also called transdifferentiation, is valuable for cell fate studies and regenerative medicine. Current approaches to transdifferentiation are usually achieved by directly targeting the nuclear functions, such as manipulating the lineage-specific transcriptional factors, microRNAs, and epigenetic modifications. Here, a robust method to convert fibroblasts to neurons through targeting the cytoskeleton followed by exposure to lineage-specification surroundings is reported. Treatment of human foreskin fibroblasts with a single molecule inhibitor of the actomyosin contraction, can disrupt the cytoskeleton, promote cell softening and nuclear export of YAP/TAZ, and induce a neuron-like state. These neuron-like cells can be further converted into mature neurons, while single-cell RNA-seq shows the homogeneity of these cells during the induction process. Finally, transcriptomic analysis shows that cytoskeletal disruption collapses the original lineage expression profile and evokes an intermediate state. These findings shed a light on the underestimated role of the cytoskeleton in maintaining cell identity and provide a paradigm for lineage conversion through the regulation of mechanical properties.