Targeted degradation of sense and antisense C9orf72 RNA foci as therapy for amyotrophic lateral sclerosis and frontotemporal dementia (strand specific RNA-seq)

Purpose: The purpose of this experiment is to identify expression changes after ASO-dependent depletion of mouse C9orf72 in the spinal cord of wild-type C57Bl/6 female mice. Methods: Strand specific RNA-seq was performed using RNAs extracted from spinal cord of C57Bl/6 mice two weeks after intracerebroventricular stereotactic injection of saline (n=3), a control ASO (n=3) or an ASO targeting mouse C9orf72 (n=3). C9orf72 RNA levels were reduced to approximately 30% of control levels in spinal cords from mice treated with the C9orf72 ASO. Results: Statistical comparison of RPKM values between RNAs from C9orf72 and control ASO treated animals or C9orf72 and saline treated samples revealed that only 12 genes were consistently upregulated (defined by P<0.05 adjusted for multiple testing) and 12 genes including C9orf72 were downregulated (defined by P<0.05 adjusted for multiple testing). Conclusions: Only few RNA expression changes were identified in the spinal cord following reduction of C9orf72. Use of strand specific RNA-seq to test the consequences of C9orf72 loss of function in mouse spinal cord.