GSE125654
RNA-seq analysis of NSC-34 mouse motor neuron-like cells treated with Negative Control siRNA#1 (siNC#1), siNC#2, Fus siRNA#1 (siFus#1), siFus#4, siFus#5 and siRNA (-) control
Fused in sarcoma/translated in liposarcoma (FUS) is a causative gene of familial amyotrophic lateral sclerosis (fALS). Mutated FUS causes accumulation of DNA damage and stress granule (SG) formation, etc., thereby motor neuron (MN) death. However, key molecular aetiology of mutated FUS-dependent fALS (fALS-FUS) remains unclear. Here, both regular bioinformatics and Bayesian gene regulatory networks (GRN) analyses were applied to large-scale transcriptome datasets of induced pluripotent stem cell (iPSC)-derived MNs possessing wild-type form of FUS and mutated FUSH517D (FUSH517D MNs). From regular bioinformatics provided DNA damage response (DDR)-related genes were uniformly down-regulated in FUSH517D MNs. Bayesian GRN calculated by Super-Computer identified miR-125b-5p, TIMELESS and PRKDC as "hub genes/miRNA" which influence the GRNs. miR-125b-5p was up-regulated in FUSH517D MNs and negatively correlated with FUS, TIMELESS and miR-125b-5p target mRNAs. Introduction of miR-125b-5p suppressed Fus, Timeless and DDR-related genes in addition to miR-125b-5p targets in expression, and caused DNA damage. Furthermore, knocking-down Timeless expression caused DNA damage. PRKDC was down-regulated in FUSH517D MNs and the cellular model analyses validated DNA damage under impaired DNA-PK activity promoted FUS mis-localization to SGs. Collectively, our strategy with Bayesian GRNs based on the iPSC model would provide the first compelling evidence to elucidate fALS-FUSH517D molecular aetiology. Overall design: To evaluate the effect of down-regulating Fus expression levels in motor neuron, NSC-34 were treated with siNC#1, siNC#2, siFus#1, siFus#4, siFus#5 and siRNA (-) control and standard RNA-seq was performed. 6 samples were analyzed. "siRNA (-)", "siNC#1" and "siNC#2" are control.