Fig. 1.

Effect of sHN and its variants on neurotoxicity by Aβ1–42. A, Primary cultured cortical neurons were treated with 25 μm Aβ1–42 in the presence or absence of sHN (10 nm,L; 10 μm,H), 10 nm sHNG (L), or 10 μm sHNA (H). In these experiments, the indicated final concentrations of HN peptides were added 16 hr before the onset of treatment with Aβ1–42. Cell mortality (left) was measured 72 hr after Aβ treatment by trypan blue exclusion assay. Cell viability (right) was measured 72 hr after Aβ treatment by calcein assay in independent experiments same as in theleft panel. Similar experiments were performed at least three times with reproducible results. B, Seventy-two hours after treatment with Aβ1–42 in the presence or absence of HN peptides, neurons were stained with calcein AM, whose cytoplasmic fluorescence represents cell viability. Representative microscopic views are indicated. The insets indicate the twofold magnified views of the similarly treated cultures independent from the cultures shown. Similar experiments were performed at least three times. C, Primary cultured neurons were treated with 25 μm Aβ25–35 in the presence or absence of sHN (10 nm,L; 10 μm,H), sHNG (10 nm,L; 10 μm,H), or 10 μm(H) sHNA. Seventy-two hours after treatment, cell viability (measured by calcein fluorescence;right), as well as cell mortality (measured by trypan blue exclusion assay; left) were measured. All values in this study indicate means ± SD of at least three independent experiments. ** and * indicate significant and not significant versus Aβ treatment, respectively.