Expression data from normal adrenal gland and aldosterone-producing adenoma

The source of aldosterone in 30 to 40 % of patients with primary hyperaldosteronism (PA) is unilateral aldosterone-producing adenoma (APA). The mechanisms causing elevated aldosterone production in APA are unknown. Herein, we examined expression of G-protein coupled receptors (GPCR) in APA and demonstrate that compared to normal adrenals there is a general elevation of certain GPCR in many APA and/or ectopic expression of GPCR in others. RNA samples from normal adrenals (n = 5), APAs (n = 10), and cortisol-producing adenomas (CPAs) (n=13) were used on 15 genomic expression arrays, each of which included 223 GPCR transcripts presented in at least one out of 15 of the independent microarrays. The array results were confirmed using real-time RT-PCR (qPCR). Four GPCR transcripts exhibited a statistically significant increase that was greater than 3-fold compared to normal adrenals, suggesting a general increase in expression compared to normal adrenal glands. Four GPCR transcripts exhibited a greater than 15-fold increase of expression in one or more of the APA samples compared to normal adrenals. qPCR analysis confirmed array data and found the receptors with the highest fold increase in APA expression to be luteinizing hormone receptor (LH-R), serotonin receptor 4 (HTR4), gonadotropin-releasing hormone receptor (GnRHR), glutamate receptor metabotropic 3 (GRM3), endothelin receptor type B-like protein (GPR37), and ACTH receptor (MC2R). There are also sporadic increased expressions of these genes in the CPAs. Together, these findings suggest a potential role of altered GPCR expression in many cases of PA and provide candidate GPCR for further study.

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Ye P, Mariniello B, Mantero F, Shibata H, Rainey WE