Divergent transcriptional regulation of astrocyte reactivity across disorders [TR_ATAC_LPS]

Single-nuclei Assay for Transposase-Accessible Chromatin with sequencing (snATACseq) was applied to examine chromatin landscape changes and transcriptional regulator (TR) DNA motif accessibility in reactive astrocytes following neuroinflammatory insult by systemic administration of lipopolysaccharide (LPS). Astrocyte nuclei were isolated from the spinal cord of wild type mice and mice with astrocyte-specific conditional gene deletion (cKO) of test-case TRs, SMARCA4 (Smarca4-astro-cKO) or STAT3 knockout (Stat3-astro-cKO). Comparison of differential chromatin accessibility revealed substantial remodeling during astrocyte reactivity, with more chromatin opening than closing. Marked alterations in access to LPS reactivity-associated TR motifs were also detected. Overall design: Astrocyte nuclei were isolated from the spinal cord of wild type, Smarca4-astro-cKO, and Stat3-astro-cKO mice 24 hours following intraperitoneal injection of 5 mg/Kg LPS. Equivalent spinal cord tissues were examined from genotype matched healthy control mice.