ECE2022 Poster Presentations Adrenal and Cardiovascular Endocrinology (87 abstracts)
Introduction: Transcriptional regulation of gene expression by miRNAs is critical for the fine-tuning of stress response. However, its role in hypercortisolism has not been explored well. After exploring circulating miRNAs in Cushing Syndrome (CS) as biomarkers our aim was to investigate their origin and their role in adrenal tissue.
Methods: Next generation sequencing (NGS) based miRNA profiling was performed in adrenal samples from patients of German Cushings registry: (1) Cortisol-Producing-Adenoma (CPA, n=8), (2) adrenals of patients with Cushings Disease after adrenalectomy (CD, n=8) and (3) controls (adrenal samples of patients with pheochromocytoma (n=8). NGS data analysis and principal component analysis (PCA) clustering was performed by R (version 4.1). miRNAs were additionally validated by QPCR in other subtypes of ACTH independent CS (PBMAH, n=10) and ACTH dependent CS (Ectopic Cushings syndrome, n=3). ACTH stimulation were done in 12 weeks-old female C57Bl6J mice according to protocol established previously. Adrenal glands were collected from the mice at 0 min (baseline), 10, 30, and 60 min upon ACTH stimulation for miRNA extraction and QPCR analysis.
Results: miRNA based NGS revealed miRNA profiles to be significantly different amongst the groups of Cushings Syndrome (CD, CPA) and controls. Interestingly, 17 miRNAs significantly differ between the CS subtypes (P<0.05). Of these, four miRNAs were found to be significantly upregulated in CPA, in comparison to both CD and Controls. These upregulated miRNAs were taken for validation by QPCR. Upregulated expression of hsa-miR-139-3p (P=0.01, l2fc>1.4), hsa-miR-1247-5p (P=0.02, l2fc>2.5) in CPA compared to both CD and Controls could be confirmed by QPCR. Next, the validated miRNAs were analysed in other subtypes of CS. Hsa-miR-1247-5p was upregulated only in ACTH independent forms of CS (PBMAH (l2fc>2.24 P=0.003) and CPA (l2fc>2.24 P=0.003)). Incidentally, miR-1247-5p was not found in the previously characterized circulating miRNA profile in both CPA and CD. Finally, hsa-miR-1247-5p was found to show no differential expression in the murine adrenal tissues at different time points in comparison to the positive control of miR-96-5p.
Conclusion: This study identifies adrenal miRNAs to be regulated in ACTH dependent and independent manner in CS. ACTH independent upregulation of miRNA-1247-5p as a possible contributor to the hypercortisolism pathology in CPA and PBMAH was identified.
21 May 2022 - 24 May 2022