FIGURE 7.

SREBP-2 is involved in necroptosis of l-Nor-treated SH-SY5Y cells. A–C, the SREBP-2 inhibitor betulin suppressed l-Nor-induced vacuolation, neurite retraction, and cell death. The cells were treated with 10 μm betulin or 3 mm l-Nor or both for 24–48 h. Representative phase-contrast images of cells 24 h after treatment (A), and cell viabilities 48 h after treatment (B) are shown. Data are shown as mean ± S.D. from two experiments (n = 5). *, p < 0.05. N.S., not significant. Scale bar, 10 μm. Arrow indicates cytoplasmic vacuoles. C, betulin attenuates the retraction of neurite-like projections caused by l-Nor. The cells were incubated with anti-FAK antibody to visualize neuronal projections and DAPI to stain the nucleus and observed under confocal fluorescence microscopy. Scale bar, 10 μm. Arrow indicates neurite-like projection. D and E, dominant-negative SREBP-2 suppressed l-Nor-induced cell death. SH-SY5Y cells stably expressing dominant-negative SREBP-2 (SREBP2DN) were treated with 3 mm l-Nor for 48 h and examined for viability (D) and intracellular ATP levels (E). Parental SH-SY5Y cells were also used as a control. Data are shown as mean ± S.D. from two experiments (n = 16). *, p < 0.05. N.S., not significant.