Gene Expression Analysis of the Human Astrocytoma Cell after A beta(25-35) Stimulation Followed by Ibuprofen Administration

Background: The molecular events leading to the development of sporadic late-onset Alzheimer's disease (AD) have not been defined. A number of mechanism for the protective effects of non-steroidal anti-inflammatory drugs (NSAIDs) in AD have been proposed. We investigated the ibuprofen effect of global gene expression on the amyloid-beta(25-35)(A beta(25-35))-stimulated human astrocytoma cell. Methods: U373MG, a human astrocytoma cell line, was incubated with 25 mu M of aggregated A beta(25-35) or aggregated A beta(25-35) plus 100 mu M ibuprofen at 37 degrees C for 24 hours. Cells treated with ibuprofen alone were used as the negative control. Differential gene expression analysis was carried out with the Illumina human whole genome microarray. Real-time reverse transcriptase polymerase chain reaction (RT-PCR) was also done to validate the gene expression changes. After Welch's t-test, the significant subset of outlier genes were identified by an expression change cut-off 1.5 fold, p<0.05. Kyoto Encyclopedia of Genes and Genomes database was used for cellular signaling pathway analysis. Results: A total of 371 differentially expressed genes were identified from 16,692 detectable signals in A beta(25-35) peptide stimulated U373MG cells- 182 up-regulated genes with 21 biological pathways including biosynthesis of steroid, peroxisome proliferator-activated receptor signaling pathway and focal adhesion and 189 down-regulated genes with 14 biological pathways including transforming growth factor-beta signaling pathway, axon guidance and mitogen activated protein kinase signaling pathway. Ibuprofen suppressed the up-regulated expression of immunity/inflammation (especially, SERPINE1), signal pathway, metabolism and cancer-related genes. The expression of microarray data was confirmed by real-time RT-PCR. Conclusion: Aggregated A beta(25-35) induces expression of widespread transcriptional alterations, namely 21 functional groups 182 up-regulated genes and 14 functional groups 189 down-regulated genes in U373MG cells. Ibuprofen, a commonly used NSAID, suppressed A beta(25-35)-induced increase of global changes in transcription of sets of genes especially immunity/inflammation, signal pathway, metabolism and cancer-related genes.