FIGURE 1.

SI dose-dependently decreases accumulation of Htt inclusions in PC12 cells. Expression and accumulation of Htt containing expanded polyglutamine (polyQ) were induced by 5 μm ponasterone for 24 h. Induced cultures were treated with either vehicle (Ctl), 1–100 μm SI, or 50 μm cystamine. A, representative images of induced cultures treated with either vehicle (Ctl, top left), 1 μm SI (top middle), 100 μm SI (top right), or 50 μm cystamine (Cyst, bottom left). White arrowheads are examples of Htt aggregates, and white arrows are examples of EGFP-positive cells without aggregates. Magnification = ×20. B, quantification of aggregation levels in control, cystamine-treated, and SI-treated cultures (n = 45). C, representative dot blots; D, quantification of SDS-insoluble polyQ-Htt from untreated/uninduced (Untr) cells and induced cells treated with vehicle, SI, or cystamine (n = 3). * denotes p < 0.05 relative to control.