α1-Adrenergic Receptor Signaling in Osteoblasts Regulates Clock Genes and Bone Morphogenetic Protein 4 Expression through Up-regulation of the Transcriptional Factor Nuclear Factor IL-3 (Nfil3)/E4 Promoter-binding Protein 4 (E4BP4)

Several studies have demonstrated that the α1-adrenergic receptor (AR) plays an important role in regulating cell growth and function in osteoblasts. However, the physiological role of α1-AR signaling in bone metabolism is largely unknown. In this study, the stimulation of phenylephrine (PHE), a nonspecific α1-AR agonist, increased the transcriptional factor Nfil3/E4BP4 and led to the rhythmic expression of bone morphogenetic protein 4 (Bmp4) in...