Figure 3.

Overexpression of IκB reverses the neuroprotective effect of pretreatment with a low dose of Aβ. (A) Experimental setup for the treatment and biolistic transfection of primary cerebellar granule cells. Primary granule cells were transfected with the expression vectors by the gene gun. After 6 h the cells were pretreated with 0.1 μM Aβ-(1–40) for 24 h to activate NF-κB, and after 3 h the survivors were counted. (B) Blow-up comparing transfection of LacZ alone (Left) or in combination with transdominant negative IκB expression vector (Right). (Upper) Staining of lacZ activity with 5-bromo-4-chloro-3-indolyl β-d-galactoside (X-Gal). (Lower) Nuclear DAPI stain. Note the shrinkage of nuclei after transfection with IκB (arrows), in contrast to viable cells (arrowheads), some dark blue cells after X-Gal stain show a somewhat reduced DAPI stain. (C) Quantification of cell death in LacZ-positive cells. Means (seven independent determinations) of dying cells were depicted ± SEM (P < 0.001). Scale bar, 25 μm.