Combined Experimental and System-Level Analyses Reveal the Complex Regulatory Network of miR-124 during Human Neurogenesis [Timecourse RNA-Seq]

Non-coding RNAs regulate many biological processes including neurogenesis. The brain-enriched miR-124 is assigned as a key player of neuronal differentiation via its complex, but little understood, regulation of thousands of annotated targets. To systematically chart its regulatory functions, we used CRISPR/Cas9 gene editing to disrupt all six miR-124 alleles in human stem cells. Upon neuronal induction, miR-124-depleted cells underwent neurogenesis and became functional neurons, albeit with altered morphology and neurotransmitter specification. By RNA-induced-silencing-complex precipitation, we found that other miRNA species were upregulated in miR-124 depleted neurons. Furthermore, we identified 98 miR-124 targets of which some directly led to decreased viability. We performed advanced transcription-factor-network analysis and revealed indirect miR-124 effects on apoptosis and neuronal subtype differentiation. Our data emphasizes the need for combined experimental- and systems-level analyses to comprehensively disentangle and reveal miRNA functions, including their involvement in the neurogenesis of diverse neuronal cell types found in the human brain. RNA profile for timecourse of neuronal Neurogenin-1 and 2-triggered differentiation from human iPSCs (wildtype and ∆miR-124).