Figure 6. Reduced HSF1 promoter binding and altered nucleosome landscapes are observed at HS loci in R6/2 mice, but do not correlate with chromatin accessibility.

(A–E) Levels of HSF1 (A and D), RNA polymerase 2 (RNApol2), H3AcK9, H3AcK27 (B), and Tetra AcH4 (C and E) bound to HS promoters 2 hours after vehicle or HSP990 treatment (12 mg/kg) was determined by ChIP in 12-week-old WT and R6/2 (A–C) and 22-month-old WT and Hdh^Q150/Q150 (D and E) mouse half brains. Chromatin was immunoprecipitated, and SYBR green qPCR was performed on the resulting DNA with primers specific for the Hspa1b, Hspb1, and Dnajb1 promoters. Signal was normalized to 10% of the input for each sample. Values are mean ± SEM (n = 5 per treatment group). Black lines in A–E indicate mean signal obtained after pulldown with rabbit IgG alone (n = 2). (F) MNase digestion was performed on chromatin extracted from mouse brain tissue 2 hours after treatment with vehicle or HSP990. SYBR green was then performed using primers spanning the Hspa1b gene. Digested signal was normalized to undigested signal, and values are mean ± SEM (n = 4 per treatment group). *P < 0.05 vs. WT HSP990, ^#P < 0.05 vs. WT vehicle, Student’s t test.