Fig. 1.

Reduced viability of tau-(1–441)-infected neurons. (A) CGCs were infected at 4 days in vitro with either Lac-Z- or tau-expressing adenovirus vectors at the MOIs indicated. Survival was assessed 24 and 48 h later by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Each data point is the mean ± SE of triplicate determinations of three independent experiments and is expressed as percentage of Lac-Z-infected cells, considering the value obtained in these cells as 100% (∗, P < 0.05; ∗∗, P < 0.01 compared with Lac-Z-infected neurons). (B) Western blot analysis of lysates from tau-(1–441)-infected CGCs performed with mAb 9E10 and normalized with β-actin (Upper) and with mAb TAU-1 (Lower) and normalized with a nonspecific (N.S.) band. (C) Immunofluorescence analysis of tau-(1–441)-infected cortical neurons at MOIs of 30 (a) and 120 (b), immunostained with mAb 9E10 (green). Forty-eight hours after infection, nuclei were stained with Hoechst 33258 (blue). A cortical neuron expressing tau with a sign of degeneration (varicosity along a neurite) is shown (c). (Scale bar, 20 μm.) (D) Micrographs of Hoechst 33258-stained cortical neurons after 48 h of infection. Values corresponding to condensed nuclei and to MTT assay are reported below. (E) Western blot analysis of the NR1 subunit expression in CGCs treated with the antisense and scrambled ODNs. (F) CGCs were incubated with NR1 antisense and scrambled ODNs and then infected with Lac-Z and tau-(1–441) vectors for 48 h, when survival was determined. Data are expressed as in A.