Rev-erb beta regulates the Srebp-1c promoter and mRNA expression in skeletal muscle cells

Biochem Biophys Res Commun. 2009 Oct 30;388(4):654-9. doi: 10.1016/j.bbrc.2009.08.045. Epub 2009 Aug 12.

Abstract

The nuclear hormone receptor, Rev-erb beta operates as a transcriptional silencer. We previously demonstrated that exogenous expression of Rev-erb betaDeltaE in skeletal muscle cells increased Srebp-1c mRNA expression. We validated these in vitro observations by injection of an expression vector driving Rev-erb betaDeltaE expression into mouse tibialis muscle that resulted in increased Srebp-1c mRNA expression. Paradoxically, Rev-erb beta siRNA expression in skeletal muscle cells repressed Srebp-1c expression, and indicated that Rev-erb beta expression was necessary for Srebp-1c expression. ChIP analysis demonstrated that Rev-erb beta was recruited to the Srebp-1c promoter. Moreover, Rev-erb beta trans-activated the Srebp-1c promoter, in contrast, Rev-erb beta efficiently repressed the Rev-erb alpha promoter, a previously characterized target gene. Finally, treatment with the Rev-erb agonist (hemin) (i) increased the trans-activation of the Srebp-1c promoter by Rev-erb beta; and (ii) increased Rev-erb beta and Srebp-1c mRNA expression. These data suggest that Rev-erb beta has the potential to activate gene expression, and is a positive regulator of Srebp-1c, a regulator of lipogenesis.

MeSH terms

  • Animals
  • Base Sequence
  • Cell Line
  • Electroporation
  • Hemin / pharmacology
  • Hindlimb
  • Lipogenesis / genetics
  • Mice
  • Molecular Sequence Data
  • Muscle, Skeletal / cytology
  • Muscle, Skeletal / metabolism*
  • Promoter Regions, Genetic / drug effects
  • RNA, Messenger / biosynthesis
  • Receptors, Cytoplasmic and Nuclear / agonists
  • Receptors, Cytoplasmic and Nuclear / genetics
  • Receptors, Cytoplasmic and Nuclear / metabolism*
  • Repressor Proteins / agonists
  • Repressor Proteins / genetics
  • Repressor Proteins / metabolism*
  • Sterol Regulatory Element Binding Protein 1 / genetics*
  • Transcriptional Activation*

Substances

  • Nr1d2 protein, mouse
  • RNA, Messenger
  • Receptors, Cytoplasmic and Nuclear
  • Repressor Proteins
  • Srebf1 protein, mouse
  • Sterol Regulatory Element Binding Protein 1
  • Hemin