Fig. 7.
Deficient expression of HspBP1 in astrocytes contributes to high activity of CHIP in astrocytes. (A) Expression of HspBP1 in cultured astrocytes reduced the level of Ub1-CHIP, and major form of CHIP increased correspondingly (n = 3 independent experiments). (B) qRT-PCR showed that overexpression of HspBP1 did not influence transcription of CHIP in cultured astrocytes (n = 3 independent experiments). (C) HspBP1 expression in cultured astrocytes stabilized aggregated and soluble mHtt and suppressed induction of CHIP and Ub1-CHIP by mHtt, which was seen in Fig. 1D (n = 3 independent experiments). (D) Induction of Hsp70, CHIP, and Ub1-CHIP by heat-shock stress at 42 °C for 1 h was significantly inhibited by HspBP1 expression in DIV 30–50 astrocytes (n = 4 independent experiments). (E) Expression of HspBP1 decreased basal levels of Hsp70 in astrocytes (n = 3 independent experiments). *P < 0.05, **P < 0.01, ****P < 0.0001 (unpaired two-tailed Student’s t test). Data are represented as mean ± SEM (error bar).