title: Clenbuterol upregulates histone demethylase JHDM2a via the β2-adrenoceptor/cAMP/PKA/p-CREB signaling pathway.
abstract: BACKGROUND
  β(2)-Adrenergic receptor (β(2)-AR) signaling activated by the agonist clenbuterol is important in the metabolism of muscle and adipose cells. Additionally, the significant role of histone demethylase JHDM2a in regulating metabolic gene expression was also recently demonstrated in Jhdm2a(-/-) mice. To elucidate the molecular mechanism involved in clenbuterol-induced adipocyte reduction from an epigenetic perspective, this study focused on cAMP-responsive element binding protein (CREB) to determine whether JHDM2a is regulated by the β(2)-AR/cAMP/protein kinase A (PKA) signaling pathway.
  
  
  RESULTS
  In porcine tissues treated with clenbuterol, JHDM2a expression was upregulated, and in porcine cells, expression of exogenous CREB led to increased JHDM2a expression. In addition, changes in JHDM2a expression were coincident with variations in the phosphorylation of CREB and p-CREB/CBP interaction in porcine and human cells treated with drugs known to modify the β(2)-AR/cAMP/PKA pathway. Finally, binding assays demonstrated that CREB regulated JHDM2a by binding directly to the CRE site nearest to the transcription start site.
  
  
  CONCLUSIONS
  Our results reveal that clenbuterol activates the β(2)-AR signaling pathway upstream of JHDM2a and that CREB acts as an intermediate link regulated by cAMP-PKA to induce activity of the JHDM2a promoter. These findings suggest that clenbuterol decreases adipose cell size and increases muscle fiber size in porcine tissues by virtue of JHDM2a-mediated demethylation, which regulates downstream metabolic and related genes.
authors: State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing 100193, China.
authors: Yang
authors: Y
authors: Li
authors: Jin
authors: J
authors: He
authors: Shunchao
authors: S
authors: Sui
authors: Xiaoxiang
authors: X
authors: Hu
authors: Yaofeng
authors: Y
authors: Zhao
authors: Ning
authors: N
authors: Li
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D002460:Cell Line; D002976:Clenbuterol / Q000494:pharmacology*; D000242:Cyclic AMP / Q000378:metabolism; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D056484:Jumonji Domain-Containing Histone Demethylases / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D018343:Receptors, Adrenergic, beta-2 / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D013552:Swine; D015854:Up-Regulation / Q000187:drug effects*
chemical_list: D000318:Adrenergic beta-Agonists; D017362:Cyclic AMP Response Element-Binding Protein; D018343:Receptors, Adrenergic, beta-2; D000242:Cyclic AMP; D056484:Jumonji Domain-Containing Histone Demethylases; D017868:Cyclic AMP-Dependent Protein Kinases; D002976:Clenbuterol