Valladares A, Roncero C, Benito M, Porras A
Departamento de Bioquímica y Biología Molecular II, Instituto de Bioquímica (Centro Mixto del Consejo Superior de Investigaciones Científicas (C.S.I.C.) y de la Universidad Complutense de Madrid (U.C.M.)), Madrid, Spain.
FEBS Lett. 2001 Mar 23;493(1):6-11. doi: 10.1016/s0014-5793(01)02264-5.
Tumor necrosis factor-alpha (TNF-alpha) activates extracellular-regulated kinases (ERKs) and p38 mitogen-activated protein kinase (p38MAPK), and inhibits the expression of uncoupling protein-1 (UCP-1) and adipocyte-specific genes in rat fetal brown adipocytes. MEK inhibition with PD98059 abolished the inhibitory effect of TNF-alpha on UCP-1, but not on adipogenic genes. In contrast, inhibition of p38MAPK with SB203580 potentiated the negative effect of TNF-alpha on UCP-1 and adipogenic genes. The inhibitory action of TNF-alpha was partially correlated with changes in C/EBPalpha and beta protein levels and in their DNA binding activity, suggesting a role for these transcription factors. However, other transcription factors might explain the different regulation of UCP-1 and adipogenic genes by ERKs.
