Up-regulation of calcineurin aβ mRNA in the Alzheimer's disease brain: Assessment by cDNA microarray

Recent advances in cDNA microarray technology have made it possible to analyze expression of more than 8000 genes. Using this technology, gene expression in the hippocampus containing neurofibrillary tangle-associated lesions from an Alzheimer's disease (AD) patient was compared with expression in the parietal cortex from the same patient that lacked these lesions. We also compared gene expression using a control brain. The top 20 named genes significantly up-regulated or down-regulated only in the AD brain were determined. The most up-regulated gene proved to be calcineurin Aβ mRNA (CAβ). In situ hybridization histochemistry revealed that CAβ was significantly up-regulated in pyramidal neurons of the hippocampus in the AD brain. RT-PCR analysis revealed that CAβ was up-regulated in the hippocampus from two out of three AD brains while there were no changes in three control brains. Our study suggests that CAβ may play a crucial role in the pathophysiological mechanisms in AD.