Distinct circular DNA profile in hSOD1G93A ALS that intersects with ALS proteome changes

Numerous genes mutated in amyotrophic lateral sclerosis (ALS) share a role in DNA damage and repair, emphasizing genome disintegration in ALS. DNA instability and repair mechanisms segregate extrachromosomal circular DNAs (ec/eccDNAs) that can modulate gene expression somatically. Here, circulome profiling in a hSOD1G93A genotoxicity model of ALS revealed a 6-fold enrichment of small-size eccDNAs relative to controls. DifCir-based differential analysis identified 189 genes with patterned segregation of differentially produced per gene circles (DPpGCs) from ALS but not from control samples, implicating an inter-sample recurrence rate of at least 89% for the top 6 DPpGCs. Mass spectrometry-based ALS circulome-proteome cross-referencing revealed 31 corresponding differentially expressed proteins (DEPs), with 12 DPpGC-DEP pairs being itemized in ALS risk GWAS databases. DPpGC-DEP hotspots mainly convey neuron-specific functions counteracting ALS detriments. This is unanticipated evidence for non-random, profiled eccDNA accumulation in ALS neurodegeneration, involving putative interactions with their gene products as well as biomarker perspectives. Overall design: The data C (Control,C57BL/6J) is performed with 10 replicates. The data A (ALS,B6.Cg-Tg(SOD1*G93A)1Gur/J) is performed with 9 replicates.