Figure 3
From: Clusterin regulates β-amyloid toxicity via Dickkopf-1-driven induction of the wnt–PCP–JNK pathway
EGR1 (early growth response-1), KLF10 (Krüppel-like factor-10) and NAB2 (Ngfi-A-binding protein-2) mediate neurotoxicity and tau phosphorylation. (a) Neurons were treated o/n with Pen1 small interfering RNAs (siRNAs) to EGR1, FOS (FBJ murine osteosarcoma viral oncogene homologue), KLF10, NAB2, CCND1 (cyclin D1) and then with 3 μM Aβ1-42(olig) for 24 h and cytotoxicity assayed by the live/dead assay. Protective effects of siRNAs targeting EGR1 and KLF10 are shown. (b) Neurons were treated as in (a) and cell survival determined by the nuclear morphology assay up to 72 h. Significance values (not shown) for the effect of EGR1 and KLF10 siRNA on cell survival at each time point were ≤0.01. (c) Neurons were treated as in (a) and cell survival measured by lactate dehydrogenase (LDH) release. (d) Neurons were treated as in (a) and subsequently with 3 μM Aβ1-42(olig) for 4 h. Total lysates were collected and immunoblotted for phospho-tau using PHF-1. Immunoreactivity values for PHF-1 were normalised to total tau values; densitometric values are shown in the right. (e) Neurons were treated with Pen1-siCLU or control Pen1 siRNA and subsequently with 3 μM Aβ1-42(olig) for 3 h, RNA collected and qRT-PCR performed for DKK1 and the five Aβ/Dkk1 target genes. o/n, over night; qRT-PCR, quantitative reverse transcription polymerase chain reaction.
