FRI135 Differential Expression Of Circulating MicroRNAs In Primary Aldosteronism: Potential Biomarkers For Improved Diagnosis

Disclosure: S. Lamprou: None. S.M. MacKenzie: None. J.D. McClure: None. S. Robertson: None. A. Riddell: None. J.C. van Kralingen: None. A. Gimenez-Roqueplo: None. P. Reel: None. S. Reel: None. G. Assié: None. A. Laurence: None. F. Beuschlein: None. G. Rossi: None. J. Deinum: None. M. Reincke: None. G. Eisenhofer: None. E. Jefferson: None. M. Zennaro: None. E. Davies: None. Primary Aldosteronism (PA) is the most common endocrine hypertension subtype, caused by autonomous aldosterone secretion. While readily treatable, accurate diagnosis of PA – particularly its differentiation from primary hypertension (PHT) – is a complex and protracted process that can entail delays in effective treatment and lead to more severe comorbidities. Given the established role of microRNAs (miRNA) in regulating aldosterone biosynthesis, we hypothesize that circulating miRNAs are potentially viable biomarkers for PA that could inform more accurate and rapid diagnosis. To detect changes in circulating miRNA profiles specific to PA, we analyzed plasma levels of 172 selected microRNAs in a retrospectively-generated cohort of PHT (n=111) and PA patients (n=109). The dataset consisted of ΔCt values for each miRNA (normalized to multiple endogenous miRNAs), as determined by real time RT-qPCR assay. Two-sample t-tests were used to assess whether the means of the two disease groups are equal, corrected using False Discovery Rate (FDR; significance level q < 0.05). Ingenuity Pathway Analysis software (QIAGEN) was employed to analyze the miRNAs bioinformatically and identify mRNA targets involved in blood pressure regulation. Pathway analysis was performed to discover associations between PA and differentially-expressed miRNAs. We identified 83 circulating microRNAs that showed significant differential expression: 27 were upregulated and 56 downregulated in PA relative to PHT. The upregulated miRNA demonstrating the greatest fold change was hsa-miR-451a (FC:1.8, q=0.001), while the most downregulated was hsa-miR-409-3p (FC:0.5, q=0.001). Bioinformatics analysis predicted several dysregulated miRNAs to target mRNAs in PA-related pathways. For example, the most upregulated miRNA, hsa-miR-451a, is predicted to target mRNAs in biochemical pathways relevant to PA pathophysiology, including SGK1 and MAP3K1. SGK1 contributes to the signaling cascade induced by the mineralocorticoid receptor-aldosterone complex that stimulates Na(+) reabsorption in the kidney, while MAP3K1 participates in the Renin-Angiotensin system, a key regulator of aldosterone secretion, as part of a signaling cascade that leads to the activation of the AP1 complex in the nucleus. In addition to hsa-miR-451a, other differentially-expressed miRNAs were also revealed to target multiple mRNAs with direct and indirect connections to PA. In summary, analysis has identified miRNAs that are significantly differentially expressed in the plasma of PA patients compared to PHT patients, indicating promise for a biomarker-based approach to PA diagnosis utilizing distinctive circulating microRNA signatures. Further analysis is now being conducted to validate our findings in an independent population of hypertensive patients. Presentation: Friday, June 16, 2023