The landscape of molecular mechanism for aldosterone production in aldosterone-producing adenoma

Primary aldosteronism is the most common form of secondary hypertension with a prevalence of 5-10% in hypertensive patients. Aldosterone-producing adenoma (APA) is a subtype of primary aldosteronism, and somatic mutations in KCNJ5, ATP1A1, ATP2B3, CACNA1D, CLCN2, or CTNNB1 were identified and recognized to drive aldosterone production and/or contribute to tumorigenesis in APA. Mutations of KCNJ5, ATP1A1, ATP2B3, CACNA1D, and CLCN2 are known to activate calcium signaling, and its activation potentiate CYP11B2 (aldosterone synthesis) transcription in adrenal cells. Transcriptome analyses combined with bioinformatics using APA samples were conductive for each gene mutation mediated pivotal pathway, gene ontology, and clustering. Several important intracellular molecules in increase aldosterone production were detected by transcriptome analysis, and additional functional analyses demonstrated intracellular molecular mechanisms of aldosterone production which focused on calcium signal, CYP11B2 transcription and translation. Furthermore, DNA methylation analysis revealed that promoter region of CYP11B2 was entirely hypomethylated, but that of other steroidogenic enzymes were not in APA. Integration of transcriptome and DNA methylome analysis clarified some DNA methylation associated gene expression, and the transcripts have a role for aldosterone production. In this article, we reviewed the intracellular molecular mechanisms of aldosterone production in APA, and discussed future challenges for basic studies leading to clinical practice.