First Author | Hadri KE | Year | 1997 |
Journal | J Biol Chem | Volume | 272 |
Issue | 39 | Pages | 24514-21 |
PubMed ID | 9305915 | Mgi Jnum | J:43208 |
Mgi Id | MGI:1097308 | Doi | 10.1074/jbc.272.39.24514 |
Citation | Hadri KE, et al. (1997) Differential regulation by tumor necrosis factor-alpha of beta1-, beta2-, and beta3-adrenoreceptor gene expression in 3T3-F442A adipocytes. J Biol Chem 272(39):24514-21 |
abstractText | Modulation of beta-adrenoreceptor expression by tumor necrosis factor-alpha (TNF-alpha) was investigated in murine 3T3-F442A adipocytes. TNF-alpha treatment of mature adipocytes decreased beta3-adrenoreceptor mRNA content in a time- and concentration-dependent manner, with a 8.5-fold decrease observed after a 6-h exposure to 300 pM TNF-alpha. beta1-Adrenoreceptor mRNA abundance was slightly decreased by TNF-alpha treatment, while beta2-adrenoreceptor mRNA levels were potently induced (6-fold increase at 6 h). (-)-[125I]Iodocyanopindolol saturation and competition binding experiments indicated that TNF-alpha induced a 2-fold decrease in beta3-adrenoreceptor number, a nonsignificant reduction in beta1-subtype population, and a approximately 4.5-fold increase in beta2-adrenoreceptor density. This correlated with a lower EC50 value measured for epinephrine in stimulating adenylyl cyclase, whereas the EC50 value for norepinephrine increased. Nuclear run-on assays on isolated nuclei and mRNA stability measurements showed that TNF-alpha increased both beta2-adrenoreceptor gene transcription and beta2-adrenoreceptor mRNA half-life, while beta1- and beta3- adrenoreceptor gene expression was modulated only at the transcriptional level by the cytokine. These findings demonstrate a differential modulation by TNF-alpha of the three beta-adrenoreceptor subtypes in adipocytes, which may contribute to metabolic disorders induced by the cytokine in the adipocyte. |