FRI166 Characterization of Aldosterone-producing Cell Cluster (APCC) At Single-cell Resolution

Abstract

Abstract Disclosure: N. Iwahashi: None. H. Umakoshi: None. T. Seki: None. C. Gomez-Sanchez: None. K. Mukai: None. M. Suematsu: None. Y. Umezawa: None. M. Oya: None. T. Kosaka: None. M. Seki: None. Y. Suzuki: None. Y. Horiuchi: None. K. Nishimoto: None. Y. Ogawa: None. Context: The adrenal cortex consists of zona glomerulosa (ZG), fasciculata (ZF), and reticularis. Aldosterone-producing cell clusters (APCCs) that express aldosterone synthase (CYP11B2) strongly can be frequently found in adult adrenals and harbor somatic mutations that are also present in aldosterone-producing adenomas (APAs). Primary aldosteronism is mainly caused by APAs or idiopathic hyperaldosteronism (IHA). We presume that APCCs are causing IHA and are precursors of APAs. However, the gene expression characteristics and especially the development of APCCs are not well understood. Objective: This study aimed to analyze the transcriptome of APCCs at single-cell resolution and infer the developmental trajectory. Methods: Single-cell RNA sequencing (scRNA-seq) was performed on two adult adrenals. Results: Immunohistochemical analyses confirmed the presence of APCCs in the two adrenals. scRNA-seq data of 6770 adrenal cells were obtained and 2928 high-quality cells were selected after quality control procedures. Unsupervised clustering and marker gene expressions such as CYP11A1 and NR5A1 identified 1765 adrenocortical cells, which were further divided into six clusters (B1-6). Using the list of APCC/ZG upregulated genes from our previously reported DNA microarray study, three clusters (B1, B3, and B6, totaling 923 cells) were identified as APCC/ZG cells. By further subclustering, the APCC/ZG cells were divided into 3 clusters (C1, C2, and C3). The APCC cluster (C3, 64 cells) and ZG cluster (C1, 447 cells) were identified. Cluster C2 seemed to be ZG-to-ZF transitional cells. RNA velocity analysis, which aimed to infer the direction of differentiation, inferred a direction of development from ZG cells to APCCs. Conclusion: Our results revealed the gene expression characteristics of APCC at single-cell resolution and show that some ZG cells remodel into APCCs. Presentation: Friday, June 16, 2023