THE MIGRATORY CAPACITY OF HTR8/SVNEO CELLS UNDER HYPOXIA IS REGULATED BY KLF6

Buenos Aires

Congreso; IFPA 2019 - VIII SLIMP; 2019

IFPA - SLIMP

Objectives: Common pregnancy complications such as preeclampsia areassociated to alterations in physiological oxygen levels and the transcriptionalresponse to hypoxia, where HIF-1a plays an essential role. KLF6 is atranscription factor early activated in response to hypoxia in a partiallyHIF-1a-dependent manner. Herein, we evaluated KLF6 impact on themigratory capacity of trophoblast cells under hypoxiaMethods: The HTR8/SVneo cell line was used as a migratory trophoblastcell model. KLF6 expression was either silenced with a specific siRNA orstably overexpressed through pLenti-KLF6 transduction. Cells werecultured in a hypoxia chamber (1% O2). Migration was evaluated in woundhealing assays. The expression of migration-related molecules such asMMP9, MMP2, and uPAR, as well as that of HIF-1a was analyzed by qRTPCRand western blot, respectively. MMP activity was detected byzymography assays. Reactive oxygen species (ROS) were measured by flowcytometry using the H2DCFDA probe.Results: KLF6 silencing in hypoxia conditions leads to an increase in cellmigration accompanied by an increase in MMP9 protein expression andactivity, whereasMMP2 and uPAr remain unmodified. Surprisingly, HIF-1atranscript and protein levels increase when KLF6 is downregulated andHIF-1a protein level decrease in HTR8/SVneo stably overexpressing KLF6as compared to the control cell line. HIF-1a expression is partially restoredby N-acetylcysteine treatment of KLF6-silenced cells. Thus, modulation ofHIF-1a expression could be a direct transcriptional consequence of KLF6absence or an indirect response to ROS induced in KLF6-silenced cells.Conclusion: Herein, we demonstrate that KLF6 modulates the migration oftrophoblasts in hypoxia since its downregulation releases the migrationmachinery. These results are in line with a higher KLF6-expression reportedin the placental bed from preeclamptic pregnancies. In addition,present results suggest a regulation loop between two transcription factors,KLF6 and HIF-1a, relevant for trophoblast physiology and pathophysiology.