CONICET | Buscador de Institutos y Recursos Humanos

Among lipoxygenase products of arachidonic acid metabolism, 5-HETE,5-HPETE and 5-oxo-ETE, act through a membrane receptor named OXER1. 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. Using a H295R cell line characterized by the stable overexpression of OXER1 we found that 5-oxo-ETE, agonist of OXER1, produced an increase in cell migration and proliferation. We also detected an increase in migration in the wild type cells but not in proliferation.In this work we studied the signal transduction pathways that were induced in 5-oxo-ETE stimulation of H295R cells.H295R cells were cultured under different conditions, cell migration was evaluated measuring wound healing 24 h after scratch and western blot assays were performed using specific antibodies that recognize intermediates in different signal transduction pathways.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, while pAKTremained constant.In conclusion, OXER1 activation in H295R cells is involved not only in PKA and PKC dependent activation of steroidogenesis but also in other cell functions like migration through other signal transduction pathways.