Oxyquinoline derivative activates HIF-1 and increases transepithelial resistance of BeWo b30 monolayer
Objectives: There is conflicting evidence that HIF-1 in hypoxia in the trophoblast can be both a pathogenetic mechanism of placental barrier dysfunction and an adaptive mechanism that protects the trophoblast. We studied the effect of the oxyquinoline derivative, the inhibitor of HIF prolyl hydroxylase, on the activity of HIF-1 and changes in the transepithelial resistance (TEER) in BeWo b30 cell monolayer.
Methods: BeWo b30 cell line stably expressing HIF1 ODD-luc reporter [Poloznikov A.A. et al., 2017] was grown in the DMEM with L-glutamine, 4,5 g glucose/L and Earle’s salts containing 10% FBS, 100 U/ml penicillin and 100 mg/ml streptomycin in 96-well Transwell plate. Cells were seeded with a density of 20,000 to 160,000 cells per insert. After 2 days of cultivation, a 10 mM solution of the oxyquinoline derivative in the medium was applied to the cells for 6 hours. HIF-1 activity and TEER were measured before and after drug application.
Results: When the drug was applied, a pronounced activation of the reporter was observed, suggesting HIF-1 activation. Seeding density of 20, 40, 80, and 160 thousand cells per insert after 2 days resulted in 64.0±10.7, 77.4±4.6, 64.5±6.0, and 60.8±3.1 U*cm2, respectively, and drug application resulted in TEER of 62.7±17.9, 137.9±0.4, 135.9±4.4, and 152.1±5.6 U*cm2, respectively. These changes may possibly be explained by increased proliferation of cells. However, this doesn't explain lack of increase in TEER at a cell density 20,000 per insert.
Conclusion: The oxyquinoline derivative activates HIF1 ODD-luc reporter in BeWo b30 cells, suggesting HIF-1 activation. This activation leads to an increase in TEER values which may be explained by increased cell proliferation, but more research is needed to find out the exact mechanism.