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Gene expression analysis following hypoxia–reoxygenation in rat gastric epithelial cells using a high-density oligonucleotide array

Abstract Recent investigations have demonstrated that the signaling of hypoxia–re-oxygenation is a major contributing pathway leading to gastric mucosal injury induced by stress, non-steroidal anti-inflammatory drugs, and Helicobacter pylori. The aim of the present study was to perform a gene expression analysis on the gastric mucosal cellular response to hypoxia–reoxygenation using a high-density oligonucleotide array. Cells were subjected to hypoxia with 95% N2 and 5% CO2 at 37°C for 2 h. Reoxygenation was initiated by placing the cells in an environment of normoxia for 2 h. Total RNA was extracted, and differences in gene expression profiles between the normoxia and hypoxia–reoxygenation groups were investigated using a GeneChip of Rat Toxicology U34 array (Affymetrix). Hypoxia–reoxygenation up-regulated the stress-related genes (heat shock protein-70 [HSP-70], catalase). The enhanced expression of HSP-70 was confirmed by Western blot analysis. In conclusion, these results suggest that up-regulation of the HSP-70 gene after reoxygenation may play a role in maintaining cell survival and supporting cell function as a molecular chaperone.