Oxer1 regulates cell migration and proliferation in H295R human adrenocortical cells

NEUMAN, I.; CORNEJO MACIEL, F.; LEMIÑA, N.

Munich, Baviera

Congreso; XXIInd Adrenal Cortex Conference; 2018

Adrenal Cortex Conference

Among lipoxygenase products of arachidonic acid metabolism, 5-HETE, 5-HpETE and 5-oxo-ETE act through a membrane receptor named OXER1. These compounds are produced in steroidogenic cells and are required for the activation of steroid production. We found that human adrenocortical H295R cells express OXER1 and that, in this cell type, this receptor is involved in the PKA and PKC-dependent stimulation of steroidogenesis. Other authors have postulated that 5-oxo-ETE is a potent activator of human neutrophil migration and of prostate cancer cell proliferation. Both effects are mediated by the activation of its receptor. In this work, we studied the effect of OXER1 activation on the migration and proliferation of H295R cells. Cells were cultured under different conditions, cell migration was evaluated measuring wound healing 24 h after scratch and cell proliferation by crystal violet assay 96 h after stimulation. Western blot assays were performed using specific antibodies that recognize intermediates in different signal transduction pathways.Treatment with 500 nM 5-oxo-ETE, agonist of OXER1, produced an increase in cell migration. This result was also obtained using H295R cells that overexpress OXER1. Cell migration was differently affected when inhibitors of different signal transduction pathways were used: while no effect was observed in 5-oxo-ETE induced migration using an inhibitor of PI3K/AKT pathway, an increase was obtained using a PKA inhibitor and a decrease was produced by inhibition of ERK1/2 and P38. In accordance to this, Western blot analyses revealed a time-dependent increase in ERK 1/2 and P38 phosphorylation after 5-oxo-ETE stimulation.The overexpression of OXER1 in H295R cells caused an increase in cell proliferation, which was blocked by the inhibition of endogenous 5-lipoxygenase. In conclusion, the membrane receptor OXER1 is involved not only in the induction of StAR protein and activation of steroidogenesis triggered by cAMP or Angiotensin II, but also in other cell functions like migration and proliferation, through other signal transduction pathways.