Figure 6.

Effects of modified KiSS-1 expression and anti-KP on Aβ, PrP, and IAPP neurotoxicity in SH-SY5Y neurons. Neuronal SHSY-5Y cell cultures (A) were treated with control siRNA or KiSS-1 siRNA and allowed to recover for 48 h prior to exposure to Aβ 1–42, Aβ 25–35, PrP 106–126, or IAPP 1–37 (5 μM each). Cell viability was determined by the MTT assay. The effects of 10 μg/mL anti-KP 45–54 antibody, 10 μM KP receptor antagonist P234, or 10 μM NPFF receptor antagonist RF9 on the toxicity of 5 μM Aβ 1–42 (B) were tested in human SH-SY5Y neuroblastoma cell cultures, with cell viability determined by the MTT assay. Neuronal SHSY-5Y cells transfected and stably overexpressing (C) either control expression vector (PCont) or expression vector containing the KiSS-1 gene (PKiSS) were treated with Aβ 1–42, Aβ 25–35, PrP 106–126, or IAPP 1–37 (5 μM each) and cell viability determined by the MTT assay after 24 h. The effects of 10 μg/mL anti-KP 45–54 antibody, 10 μM KP receptor antagonist P234, or 10 μM NPFF receptor antagonist RF9 on the toxicity of 5 μM Aβ 1–42 (D) were tested in KiSS-1 overexpressing SH-SY5Y neuroblastoma cell cultures, with cell viability determined by the MTT assay. All results are expressed as % control (SHSY-5Y neurons, siRNA treated SHSY-5Y neurons, or transfected SHSY-5Y neurons in media alone) and are expressed as the mean ± SEM (n = 8). (* = P < 0.05 vs control (media alone); † = P < 0.05 vs control siRNA (A), Aβ alone (B and D), and PCont vector (C); one-way ANOVA.)