SAT-LB012 Differential miRNA-Transcriptomic and Proteomic Profile in Urinary Exosomes of Subjects with "Nonclassic" Apparent Mineralocorticoid Excess Syndrome

Mineralocorticoid arterial hypertension has risen as one of the most prevalent causes of secondary hypertension, where 11β-hydroxysteroid dehydrogenase type-2 partial deficiency (also known as non-classical AME (NC-AME)), could reach a prevalence of 7% in Chilean subjects. The phenotype of NC-AME is associated to high serum cortisol (F) to cortisone (E) ratio &low E, high potassium excretion and low-renin activity (Tapia-Castillo et al, JCEM 2018). However, local metabolic changes in NC-AME affecting protein, RNA and miRNA expression have not been studied. Nowadays, exosomes technology allows to identify those biomolecules in specific biofluids. Aim: To identify the transcriptomic (miRNA) and proteomic profile in urinary exosomes of subjects with non-classical AME and healthy subjects. Subjects and methods: A cross-sectional study was carried out in 24 subjects (10-65 years). The subjects were classified as NC-AME (F/E ratio> percentile 75th, and E < percentile 25th) and healthy controls. The levels of F, E, aldosterone and plasma renin activity were quantified. The exosomes were obtained from morning urine samples by differential ultracentrifugation and were characterized with the NS300 nanoparticle analyzer, electron microscopy and western-blot for CD63 and TSG101. The total exosomal RNA was isolated with Trizol reagent. The Illumina TruSeq Small RNA kit was used and sequenced by Illumina NextSeq-500. Additionally, an exosomal proteomic profile was obtained by LC-MS/MS 5600 Triple TOF (ABSciex, Framingham, USA). Bioinformatic analyzes were performed with miRdeep2, PANTHER and STRING. Results: In urinary exosomes, we found355 from 2822 predicted miRNAs , of which 170 miRNA were found to be upregulated and 185 miRNA were dowregulated in subjects with NC-AME vs controls. We also found miR-204-5p (change times = 0.115; p = 0.001) and have miR-192-5p (change times = 0.246; p = 0.03), present a significantly lower expression in NC-AME subjects vs controls, both confirmed by Taqman PCR. Genetic ontology analyses indicate that both miRNAs would have a role in steroid biosynthesis (hsa00100). We identified around 350 exosomal proteins, of which 79 proteins were commonly expressed in both groups and 23 proteins were exclusively expressed in subjects with NC-AME, highlighting the 14-3-3 (YWHAE, YWHAZ), RHOA and CDC42 protein. Conclusion: This is the first study on urinary exosomes showing the differential expression of miRNA (miR-204 and miR-192) and proteins (14-3-3, RHOA and CDC42) which highlight its potential role as biomarkers and regulators of the high mineralocorticoid activity in NC-AME subjects. Acknowledgements: This study was supported by grants CONICYT-FONDECYT 1150437, 1160695, 1160836, CONICYT-FONDEQUIP EQM150023, IMII P09/16-F, & CETREN-UC. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. Abstracts presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.