Retinoic Acid Enhances Natriuretic Peptide Receptor‐A gene Transcription: Role of Additive Effect of Retinoic Acid Receptor‐α and Ets‐1

Abstract

Activation of guanylyl cyclase/natriuretic peptide receptor‐A (GC‐A/NPRA) by cardiac hormones atrial and brain natriuretic peptides produces the second messenger cGMP, which activates downstream signaling and biological effects of NPRA including vasorelaxation, anti‐mitogenic, and anti‐hypertrophic effects. The objective of the present study was to gain insight into the signaling mechanism of all‐trans retinoic acid (ATRA) in the regulation of Npr1 gene (coding for GC‐A/NPRA) transcription in cultured mouse mesangial cells. Cells were cultured in Dulbecco's modified Eagle's medium containing 10% fetal bovine serum and ITS (insulin,transferrin, and sodium selenite) and were transiently transfected using Lipofectamine. The results showed that ATRA significantly increased Npr1 mRNA, NPRA protein expression, and intracellular accumulation of cGMP in a dose‐dependent manner. ATRA caused a 7‐fold increase in luciferase activity from the region −365 to +55 base pairs of the Npr1 promoter. ATRA‐dependent Npr1 gene transcription was effectively inhibited by Ro 41‐5253, a specific antagonist for RARα. ATRA enhanced in vivo binding of Ets‐1 to Npr1 promoter as confirmed by ChIP assay. Moreover, sequential ChIP assay showed simultaneous presence of RARα and Ets‐1 in the Npr1 promoter containing Ets‐1 binding sites. Collectively, our results show that retinoic acid induces Npr1 gene transcription and expression via RARα and Ets‐1 transcription factors. The findings of the present studies will have important implications in prevention of high blood pressure and cardiac remodeling.