8399 Adherens Junctions Regulate Aldosterone Production and Zona Glomerulosa Morphogenesis

Abstract Disclosure: M. Berber: None. N.A. Guagliardo: None. P.Q. Barrett: None. B. Haykir: None. V. Chortis: None. K.S. Borges: None. D.L. Carlone: None. D.T. Breault: None. Primary aldosteronism (PA) caused by the autonomous production of aldosterone by zona Glomerulosa (zG) cells of the adrenal gland is the most common cause of endocrine hypertension, which increases the risk of cardiovascular and renal disease, independent of blood pressure. Current treatments with mineralocorticoid receptor antagonists do not fully mitigate these risks. Thus, a better understanding of the mechanisms underlying PA pathogenesis is important for the development of new therapeutic strategies. zG cells are organized in multicellular rosette structures, which are the functional aldosterone-producing units. Rosettes are stabilized by intercellular adherens junctions (AJs) comprised of cadherins, beta-catenin (βCat) and alpha-catenin (αCat), which link to the actin non-muscle myosin II (NMII) network. Recent data implicate AJs and rosettes in aldosterone-producing cell clusters and an unbiased proteomic analysis of aldosterone-producing adenomas detected an upregulation of the GTPase RhoC, an important regulator of AJ stability.We hypothesized that AJs are potent modulators of aldosterone production and zG morphogenesis with important implications for PA. Using the NCI-H295R cell line with confocal microscopic and co-immunoprecipitation assays, we found that potassium (K+) and angiotensin II (AngII) stimulation markedly enhanced the formation and maintenance of AJs. In addition, treatment with inhibitors of Rho-associated kinase (ROCK) (Y-27632) and NMII (blebbistatin) largely abrogated the effects of K+ and AngII stimulation on AJs, suggesting the Rho-ROCK-NMII pathway regulates AJ stability in the zG. Moreover, disruption of AJs, using either blebbistatin or deletion of αCat using CRISPR, blunted the aldosterone response to K+ stimulation (100% and 50%, respectively). Furthermore, zG-specific deletion of αCat (αCat-LOF) in mice led to disruption of AJs, impaired rosette formation and decreased 24-hour urinary aldosterone excretion on standard (Control 5.6±1.7 ng/mg; αCat-LOF 2.9±0.7 ng/mg (aldosterone/creatinine)) or high K+ (Control: 34.7±13.7 ng/mg; αCat-LOF 19.4±9.5 ng/mg (aldosterone/creatinine)) diets. Finally, mice with zG-specific βcat-GOF demonstrated enhanced AJ stability, increased rosette size and zG hyperplasia, which was abrogated in zG-specific bigenic βCat-GOF::αCat-LOF mice, without affecting gene expression of canonical βcat targets. These data indicate that AJs modulate aldosterone production and zG morphology, revealing AJs as a novel molecular target for the treatment of high-risk patients with PA. Presentation: 6/3/2024