Cohort of estrogen-induced microRNAs regulate adrenomedullin expression

• Published in: American journal of physiology. Regulatory, integrative and comparative physiology integrative and comparative physiology, 2016-01, Vol.310 (2), p.R209-R216
• Main Authors: Wetzel-Strong, Sarah E, Li, Manyu, Espenschied, Scott T, Caron, Kathleen M
• Format: Article
• Language: English
• Subjects: 3' Untranslated Regions; 5' Untranslated Regions; Adrenomedullin - genetics; Adrenomedullin - metabolism; Animals; Binding Sites; Cardiovascular and Renal Integration; Cells; Computational Biology; Databases, Genetic; Estrogens; Estrogens - metabolism; Female; Gene Expression Profiling; Genotype; Growth Hormone - genetics; Heart; Hemodynamics; Hormones, Reproduction and Development; Mice, 129 Strain; Mice, Inbred C57BL; Mice, Transgenic; MicroRNAs - genetics; MicroRNAs - metabolism; Myocardial Contraction; Myocardium - metabolism; Ovariectomy; Peptides; Phenotype; Protein expression; Ribonucleic acid; RNA; Rodents; Signal Transduction; Up-Regulation; Ventricular Function, Left
• ISSN: 0363-6119; 1522-1490
• DOI: 10.1152/ajpregu.00305.2014

Estrogen regulates the expression of many genes and has been correlated with differences in cardiac contraction; however, the underlying mechanisms remain poorly defined. Adrenomedullin (Adm = gene; AM = protein) is a multifunctional peptide with inotropic actions. Previous studies have demonstrated that estrogen enhances the expression of Adm, suggesting a relationship between AM and estrogen in cardiac contraction during physiological and pathological states. In this study, female mice in a mouse model of genetic Adm overexpression, abbreviated as Adm(hi/hi), were found to express 60 times more Adm in the heart than wild-type littermates, compared with the three-fold elevation of Adm previously reported in Adm(hi/hi) male hearts. Thus, this study sought to further investigate any functional consequences of increased cardiac Adm expression and begin exploring the mechanisms that regulate Adm expression in an estrogen-dependent fashion. This study revealed that heart function is enhanced in Adm(hi/hi) females, which along with Adm expression levels, was reversed following ovariectomization. Since the Adm(hi/hi) line was generated by the displacement of the 3' untranslated region (UTR), the native 3'UTR was examined for estrogen-induced microRNAs target sites to potentially explain the aberrant overexpression observed in Adm(hi/hi) female hearts. Using a bioinformatic approach, it was determined that the mouse Adm 3'UTR contains many target sites for previously characterized estrogen-induced microRNAs. This study also determined that the novel microRNA, miR-879, is another estrogen-induced microRNA that interacts with the 3'UTR of Adm to destabilize the mRNA. Together, these studies revealed that estrogen-induced microRNAs are important for balancing cardiac Adm expression in females.