Role of ATF3 in the transcription of GI-SINEs (growth inducing B2-SINEs) in DRG neurons in response to sciatic nerve crush

Injury of the sciatic nerve upregulates a specific subset of B2-SINE RNAs in Dorsal Root Ganglia (DRG) neurons that enhances axon regeneration, which we termed GI-SINEs (growth inducing SINEs). Based on ATAC-seq and transcription factor binding site analysis and in-culture perturbation of AP-1 TFs, we hypotheiszed that GI-SINEs specifically regulated by injury activated AP-1 TFs. Here we experimentally tested the role of ATF3, a CREB TF that belongs to the AP-1 TF superfamily, in the transcriptional upregulation of GI-SINEs. ATF3 was previously identified and characterized as a key activator of nerve-injury induced regeneration associated genes (RAGs) mRNA. Cre recombinase expressed under the Advillin promoter was used for ATF3-exon3 excision in a broad and specific manner in the DRG. Sciatic nerve injury was carried on on mice with a conditional knockout of ATF3 in sensory neurons and ATF3-wt mice and total RNAseq was carried on RNA extracred from on sciatic innervating DRGs (L4-L6) from the injured side ("Inj") and non-injured side (naive / "Na").