GSE42701
Direct Conversion of Fibroblasts to Neurons by Reprogramming PTB-Regulated microRNA Circuits
The induction of pluripotency or trans-differentiation of one cell type to another  can be accomplished with cell lineage-specific transcription factors. Here we report that  repression of a single RNA binding protein PTB, which occurs during normal brain  development via the action of miR-124, is sufficient to induce trans-differentiation of  fibroblasts into functional neurons. Besides its traditional role in regulated splicing, we  show that PTB has a previously undocumented function in the regulation of microRNA  functions, suppressing or enhancing microRNA targeting by competitive binding on  target mRNA or altering local RNA secondary structure. A key event during neuronal  induction is the relief of PTB-mediated blockage of microRNA action on multiple  components of the REST complex, thereby de-repressing a large array of neuronal genes,  including miR-124 and multiple neuronal-specific transcription factors, in non-neuronal  cells. This converts a negative feedback loop to a positive one to elicit cellular  reprogramming to the neuronal lineage. Overall design: Examination of PTB regulated  AGO2/microRNA targeting in Hela cells by CLIP-seq (two biological replicates) , paired-end RNA-seq (control and PTB knockdown) and 3’end stability RNA-seq  (control and PTB knockdown)