FIGURE 4.

Curcumin corrects aged hTau transgene-dependent disruption of molecular chaperone (HSP) expression. HSPs from hippocampal tissue were analyzed by immunochemistry in lysis and TBS fractions from WT, untreated hTau (Tg), and curcumin-treated hTau (Cur) mice (A). Comparisons of lysis (membrane-enriched) fractions (B–F) from the Tg group relative to the WT group showed a trend toward decreased HSP90 (B) and significant reductions in HSP70 (C) and stress-inducible HSP70 (HSP70/HSP72, D). The Cur group demonstrated similar expression of these HSPs in the lysis fraction (B–D). There was no effect of transgene on cognate HSC70 (E) or the carboxyl terminus of HSP70-interacting protein (CHIP), a Tau ubiquitin ligase (F). However, curcumin treatment in hTau mice resulted in significantly increased HSC70 levels (p < 0.05, E) and a trend toward increased CHIP levels (p = 0.079, F). In TBS (cytosolic) fractions (G–L), there were no transgene-dependent alterations in any of the HSPs measured. However, curcumin treatment in hTau mice resulted in a 3-fold elevation in HSP90 (p < 0.001, H). Asterisks indicate significant differences relative to untreated hTau mice as indicated by post hoc analyses: *, p < 0.05; **, p < 0.01; ***, p < 0.001; ****, p < 0.0001.