Changes of c-fos mRNA in Endothelial Cells Exposed to Various Intermittent Hypoxia / 天津医药

ABSTRACT

Objective To measure the mRNA expression of immediate-early gene c-fos in endothelial cells by the use of different intermittent hypoxia (IH) protocols. Methods A gas control delivery system was homemade, which pro-duced IH/re-oxygenation(ROX) environmental exposure. The endothelial cells were exposed to IH/ROX cycles, and were di-vided into three groups (A, B and C). There were five sub-groups in each group. Group A included intermittent normoxia group, standard incubator control group, continuous hypoxia group (CH), 1.5%O2 IH group and 10%O2 IH group. There were different frequency IH of 1.5%O2 and 10%O2 sub-groups in group B and group C. Hypoxia time was 15 s. The intermittent hypoxia cycle was 60 and the ROX time was different. The total cycle time was different, including 1.5 h group, 3 h group, 5 h group, 6.5 h group and 9.5 h group. The mRNA expression of immediate-early gene c-fos was measured by real-time PCR. Results There was no significant difference in the level of c-fos mRNA between intermittent normoxia group and CH group. The expression of c-fos mRNA was significantly higher in 1.5%O2 IH group and 10%O2 IH group than that of intermit-tent normoxia group, and there was a higher expression level of c-fos mRNA in 1.5%O2 IH group than that of 10%O2 IH group (P＜0.01). It was found that the mRNA expression of c-fos increased gradually at first, and then gradually decreased. The expression of c-fos mRNA was significantly higher in 5 h group than that of other groups (P＜0.01). Conclusion The mRNA expression of immediate-early gene c-fos is increased after exposing to IH/ROX in endothelial cells, which is closely related with IH extents and frequencies.