Involvement of COX-2/PGE2 signalling in hypoxia-induced angiogenic response in endothelial cells.
Bottom Line: The results demonstrated that short-term hypoxic treatment enhanced HUVECs proliferation, migration, tube formation, significantly up-regulated COX-2, VEGF, AQP1 mRNA level, protein expression and promoted PGE(2) , VEGF release.Exogenous PGE(2) augments the effects of hypoxia on HUVECs, and partially reversed the inhibitory effects of NS398 on HUVECs proliferation and angiogenic capability.Short-term hypoxic treatment enhanced angiogenic capability of ECs, and COX-2/PGE(2) signalling may play a critical role in the biological response of ECs to hypoxia.
Affiliation: State Key Laboratory of Oral Diseases, Department of Orthodontics, West China College of Stomatology, Sichuan University, Chengdu, China.Show MeSH
Related in: MedlinePlus
Mentions: At 80% confluence, HUVECs were placed in 6 well plates at 1 χ 104/cm2 and incubated with 5% CO2, 100% humidity at 37°C for two days. The cells were assigned to two groups as hypoxic group (2% O2) and normoxic control group (20% O2), while the former divided into five subgroups (1, 3, 6, 12, 24 hrs) according to different periods of hypoxic exposure. Then, the cells were subjected to hypoxia maintained using a three gas modular hypoxic incubator with CO2/O2 monitoring and CO2/N2 gas sources (Binder, Camarillo, CA, USA). Figure 1 is schematical diagram of the device. Culture medium was pre-equilibrated overnight prior to cell exposure. Cell culture plates were placed in the incubator and saturated with a gas mixture containing 2% oxygen, 5% CO2 and 93% nitrogen for the generation of hypoxia at 37°C for defined time periods (1, 3, 6, 12, 24 hrs), each with three replicates and the experiments were done for at least three times. In some experiments, the combined EP1/2 antagonist AH6809 (Sigma-Aldrich), or exogenous PGE2 (Sigma-Aldrich) and/or NS398 (Sigma-Aldrich), a selective inhibitor of COX-2, were also added into the HUVECs medium 4 hrs before hypoxic treatment.
Affiliation: State Key Laboratory of Oral Diseases, Department of Orthodontics, West China College of Stomatology, Sichuan University, Chengdu, China.