NRSF downregulation induces neuronal differentiation in mouse embryonic stem cells.

Differentiation of embryonic stem (ES) cells into neurons is accompanied by global changes in transcriptional programs. One transcription factor that has been shown to be involved in neuronal differentiation is neuron restrictive silencing factor/RE1-silencing transcription factor (NRSF/REST). NRSF is a transcriptional repressor that silences the transcription of a large number of neuronal genes by binding to a 21-bp consensus DNA sequence, the RE1 binding site/neuron-restrictive silencer elements (RE1/NRSE), present in the regulatory regions of neuronal genes. The goal of the current study was to examine the role of NRSF during differentiation of ES cells into neurons. To do this, ShRNA construct was used to downregulate NRSF in undifferentiated ES cells. Our results show that although control ES cells required induction by retinoic acid (RA) to differentiate efficiently into neurons, downregulation of NRSF was sufficient to drive the ES cells down the neuronal lineage even in the absence of RA. This downregulation also led to increased expression of mature neuronal markers, and concomitantly decreased glial fibrillary acidic protein (GFAP) expression. The results suggest that NRSF downregulation increases the population of mature neurons at the expense of GFAP-positive cells.