The RNA helicases DDX5 and DDX17 facilitate neural differentiation of human pluripotent stem cells NTERA2

Understanding human neurogenesis is critical toward regenerative medicine for neurodegeneration. However, little is known how neural differentiation is regulated by RNA helicases, which comprise a diverse class of RNA remodeling enzymes. We show here that expression of the DEAD box-containing RNA helicases DDX5 and DDX17 is abundant throughout retinoic acid-induced neural differentiation of the human pluripotent stem cell (hPSC) line NTERA2, and is mostly localized within the nucleus. Using ChIP-seq, we identify that the two RNA helicases occupy chromatin genome-wide at regions associated with neurogenesis- and differentiation-related genes in both hPSCs and their neural derivatives. Further, RNA-seq analyses indicate both DDX5 and DDX17 are mutually required for controlling transcriptional expression of these genes. We show that the two RNA helicases are not important for maintenance of stem cell state of hPSCs. In contrast, they facilitate early neural differentiation of hPSCs, generation of neurospheres from the stem cells, and expression of key neurogenic transcription factors during neural differentiation. Importantly, DDX5 and DDX17 are important for differentiation of hPSCs toward NESTIN- and TUBB3-positive cells, which represent neural progenitors and mature neurons. Collectively, our findings suggest the role of DDX5 and DDX17 in transcriptional regulation of genes involved in neurogenesis, and hence in neural differentiation of hPSCs.