Transcriptome-pathology correlations predict CSNK1E-mediated TDP-43 phosphorylation in sporadic amyotrophic lateral sclerosis

Sporadic amyotrophic lateral sclerosis (sALS) is the most common (~90%) form of ALS. There are no animal models of sALS and exact molecular mechanisms remain elusive. Here, we elucidate gene-expression profiles in laser capture microdissected enriched surviving motor neurons (MNs) from sALS lumbar spinal cords in patients who had rostral onset and caudal progression. A strong signature was detected and immunological signals were computationally filtered. The filtered dataset showed clustering groups that were significantly explained by levels of phosphorylated TDP-43 (pTDP-43). Transcriptome-pathology correlations and enhanced crosslinking and immunoprecipitation combined with sequencing (eCLIP-seq) identified that Casein kinase 1e (CSNK1E) had the highest correlation with pTDP-43 status and TDP-43 binding in its 3'UTR. Furthermore, CSNK1E interacted with TDP-43 on protein level and its overexpression lead to increased cytoplasmic pTDP-43 accumulations in iPSC-MNs, suggesting CSNK1E directly mediates TDP-43 phosphorylation. Therefore, we report an essential framework for molecular disease classification and transcriptome – pathology correlation in sALS to identify candidate genes for elucidating disease mechanisms and potential therapeutic interventions. Overall design: eCLIP-seq was performed in for TDP-43 in two controls and three sALS patients. Each sample has a size-matched input control for analysis