OXER1 is involved in adrenocortical cell proliferation

CORNEJO MACIEL, F.; NEUMAN, I.

Córdoba, Córdoba

Congreso; LII Reunión Anual Sociedad Argentina de Investigación Bioquímica y Biología Molecular; 2016

Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB)

Lipoxygenase-dependent products of arachidonic acid (AA) metabolism act through a membrane receptor named OXER1. These compounds are produced in steroidogenic cells and are required for the activation of steroid production. Human adrenocortical H295R cells express OXER1 which is involved in the PKA and PKC-dependent stimulation of steroidogenesis. Here we examined the role of OXER1 in the proliferation of H295R cells. We used a cell line characterized by the stable overexpression of OXER1 (H295R-O). The proliferation rate in these cells, measured by crystal violet assay and expressed in arbitrary units, was higher than in control cells (H295R-empty 0.028 ± 0.004; H295R-O 0.06 ± 0,01; P < 0.01). When the endogen production of lipoxygenated products was inhibited by zileuton, the H295R-O cells behaved like control cells. In addition, H295R cells treated with 8Br-cAMP 1 mM decreased the proliferation rate (control 147 ± 5; 8Br-cAMP 104 ± 3; P < 0.001), while angiotensin II did not produce any significant changes between 0.01 and 1 uM. Therefore, the activation of PKA and PKC kinases might not be involved in the activation of the proliferative process. These results support the hypothesis that lipoxygenase products acting through the activation of OXER1 are involved also in adrenal cell growth. Future experiments should focus on signal transduction pathways triggered by OXER1 activation.