Gene Expression Profile in Rat Adrenal Zona Glomerulosa Cells Stimulated with Aldosterone Secretagogues

The mineralocorticoid aldosterone mainly produced by the adrenal gland is essential for life but an abnormal excessive secretion causes severe pathological effects including hypertension and target organ injury in the heart and kidney. The aim of this study was to determine the gene regulatory network triggered by aldosterone secretagogues in a non transformed cell system. Freshly isolated rat adrenal zona glomerulosa cells were stimulated with the two main aldosterone secretagogues, angiotensin II and potassium, for two hours and subjected to whole genome expression studies using multiple biological and bioinformatics tools. Several genes were differentially expressed by Ang II (n=133) or potassium (n=216). Genes belonging to the nucleic acid binding and transcription factor activity categories were significantly enriched. A subset of the most regulated genes were confirmed by real-time RT-PCR and then their expression analyzed in time curve studies. Differentially expressed genes were grouped according to their time-response expression pattern and their promoter regions analyzed for common regulatory transcription factors binding sites. Finally, data mining with gene promoters, transcription factors and literature databases were performed to generate gene interaction networks for either Ang II or potassium. This study provides for the first time a complete study of the genes that are regulated, and the interaction between them, by aldosterone secretagogues in rat adrenal cells. Increasing our knowledge of adrenal physiology and gene regulation in non transformed cell systems would lead us to a better approach for discovery of candidate genes involved pathological conditions of the adrenal cortex.

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Romero DG, Plonczynski MW, Welsh BL, Gomez-Sanchez CE, Zhou MY, Gomez-Sanchez EP