Identification of amyloid β-peptide responsive genes by cDNA microarray technology:: Involvement of RTP801 in amyloid P-peptide toxicity

Amyloid beta-peptide (Abeta), a causative molecule in the pathogenesis of Alzheimer's disease and the main component of senile plaques, is known to be neurotoxic in vitro and in vivo. The mechanisms involved in this Abeta-mediated neurotoxicity are not fully understood, although there is evidence to suggest the involvement of oxidative stress, alterations in calcium homeostasis, and/or of CDK activators. Many studies have suggested that Abeta may exert its toxic effect via the activation of transcription factors. Therefore, we investigated Abeta-responsive genes in human neuroblastoma CHP134 cells using 3.1K human DNA microarrays. Among the several genes overexpressed or repressed by Abeta, RTP801, Hi95/sestrin 2, and stanniocalcin 2 were confirmed to be Abeta mediated overexpression in the cells by semiquantitative RT-PCR. Transient expression of the sense RTP801 gene in CHP134 cells increased sensitivity to Abeta cytotoxicity and the expression of the antisense RTP801 gene protected the cells from the Abeta toxicity. These results suggest that RTP801 might play important roles in Abeta toxicity and the pathogenesis of Alzheimer's disease.