β-Adrenergic signaling regulates NR4A nuclear receptor and metabolic gene expression in multiple tissues

The nuclear hormone receptor (NR) 4A subgroup of orphan nuclear receptors includes three members, Nur77 (NR4A1), Nurr1 (NR4A2) and Nor-1 (NR4A3). Previously we have identified the rapid and robust (in vitro and in vivo) induction of the NR4A subgroup following β-adrenergic stimulation in mouse skeletal muscle. This was concomitant with changes in the expression of genes involved in the regulation of nutrient metabolism. We have isolated mouse tissue of cardiovascular, endocrine and gastrointestinal origin at 1, 4, 8 and 24 h after a single intraperitoneal injection of the β-adrenergic agonist, isoprenaline. We similarly identified the significant induction (between 1 and 4 h) of the NR4A genes in many of these tissues. Moreover, we have utilized TaqMan® Low Density Arrays to determine the β-adrenergic-sensitive metabolic gene expression in liver, white adipose and heart. In summary, cross-talk between β-adrenergic and NR4A signaling occurs in several tissues, and is accompanied by modulation of metabolic gene expression.