RESUMO
Increased pressure of oxygen in cell culture condition in comparison with in vivo, leads to changes in expression of some genes and subsequently abnormality in some functions of cells. The aim of this study was to investigate the effect of in vitro%1 acute hypoxia on the expression of connexin 43 and CXCR4 in human bone marrow derived mesenchymal stem cells. After culturing, a group of stem cells were treated under%1 acute hypoxia for 4, 8, 16, 24 and 48 hours. In another group [Hypoxia/Re-oxygenation], the cells were exposed to normoxia condition for 8 hours following mentioned hypoxia treatment. In each case, RNA was extracted and subsequently cDNA synthesised and then the expression of connexin 43 and CXCR4 genes were compared with normoxia group using real-time PCR technique. Connexin 43 gene expression significantly increased at 4, 8 and 16 hours of hypoxia. This increase in CXCR4 expression was observed in only 16 hours hypoxia. In Hypoxia/Re-oxygenation group, although Connexin 43 gene expression was greatly increased at 4 and 8 hours, CXCR4 gene expression showed no significant change compared with normoxia group. Based on these results, O2 concentration, time of exposure to O2 and and type of it's administration play important roles in the expression of CXCR4 and Connexin 43 in human bone marrow derived mesenchymal stem cells. Regarding the main role of oxygen in expression of these genes, it would be necessary to optimise the O2 concentration to reach the maximum expression in each gene in these cells