Figure 2. Increased hippocampal p75^NTR mRNA expression associates with higher levels of Sp1 in the mouse and human HD hippocampus.

(A and B) Histograms showing p75^NTR mRNA expression analyzed by RT-PCR in the hippocampus (A) and cortex (B) of 8-month-old WT and KI mice and 12-week-old WT and R6/1 mice. Results were normalized to 18S gene expression. Data represent mean ± SEM and are expressed as fold change. (n = 5–8 for each genotype.) (C and D) Western blot for Sp1 in nuclear and cytosolic enriched fractions from the hippocampus of WT and R6/1 mice at 14 weeks of age and from control and HD patients (n = 4–6). Representative immunoblots showing Sp1 protein levels in cytosolic (loading control α-tubulin) and nuclear (loading control NeuN) fractions. Data were analyzed by Student’s 2-tailed t test. *P < 0.05, **P < 0.01, and ***P < 0.001 compared with WT mice or control human samples.