Abstract 12839: Expression and Functional Role of The Prorenin Receptor in Human Primary Aldosteronism

Hypothesis: The detection of prorenin in plasma of patients with Primary Aldosteronism (PA) suggests that prorenin plays a pathophysiologic role in PA by acting via the Pro-Renin Receptor (PRR). We therefore sought for the presence of the PRR in the normal human zona glomerulosa (ZG) and in aldosterone producing adenoma (APA), and investigated the functional response of PRR activation by prorenin on ERK1/2 phosphorylation in an adrenocortical cell line. Methods and Results: Expression levels of PRR gene were 15- and 12-fold higher than those of the housekeeping gene PBGD in the normal human adrenal cortex (n=8) and in the APAs (n=11), respectively. Similar high expression levels were found in the the H295R and HAC15 cells. The PRR protein expression was confirmed by immunohistochemistry in the human and rat normal ZG, as well as in a pure population of APA cells obtained with an immunoseparation-based technique specifically targeted to the membrane CD56. Immunoblotting, confocal and immuno-gold electron m...