Transcription profiling by array of liver from proestrus and metestrus mice to investigate ER control of liver metabolic function

In order to elucidate the mechanism underlying ER control of liver metabolic function, we investigated the genetic programs controlled by the hepatic receptor during the physiological fluctuation of circulating E2 in adult female mice. To this aim, we used Affymetrix GeneChip Arrays and compared the expression of hepatic genes in mice in two phases of the estrous cycle: Proestrus (P) and Metestrus (M), characterized by high and low circulating E2 respectively. Analysis of data demonstrated that the expression of genes involved in lipid and cholesterol metabolism changes during the reproductive cycle. To further elucidate ER transcriptional activity at M and P, we performed a whole genome ChIP experiment followed by tiling array. We observed that at M, but not at P, recruited ERs are mostly in proximity (20 kbp) of genes involved in energy metabolism, thus strengthening the hypothesis of ER playing a bridging role between metabolism and reproduction.