Ephrin-B1 and EphB4 expression and localization in steroidogenic cells of mouse adrenal gland.

Erythropoietin-producing hepatocellular (Eph) receptors and their ligands ephrin are membrane-bound molecules that modulate diverse cellular functions in various tissues. We recently reported the co-expression of Efnb1 (ephrin-B1) and Ephb4 (EphB4) in steroidogenic cells of the ovary. Based on these previous findings, we examined the expression and localization of ephrin-B1 and EphB4 in steroidogenic cells of the mouse adrenal gland using RT-PCR and immunofluorescence techniques. To the best of my knowledge, ephrin-B1 and EphB4 expression patterns in the adrenal gland are virtually unknown. We found that ephrin-B1 and EphB4 were co-expressed in steroidogenic cells of zona glomerulosa (zG) and zona fasciculata (zF) in the adrenal cortex of mice. Ephrin-B1 and EphB4 were also co-expressed in cells of x-zone (xZ) in female mice. We also found that ephrin-B1 and EphB4 expression in zG was strong and weak respectively. Ephrin-B1 and EphB4 expression in cells of zF were faint in cells of both mice while strong in juxtamedullary cells of zF in male mice. Ephrin-B1 and EphB4 expression were faint and weak in xZ in female mice respectively. The study represents the first expression analysis of ephrin-B1 and EphB4 in steroidogenic cells in the adrenal glands of the male and female mice.