Estrogen decreases TNF gene expression by blocking JNK activity and the resulting production of c-Jun and JunD
Sunil Srivastava, … , Stuart Adler, Roberto Pacifici
Sunil Srivastava, … , Stuart Adler, Roberto Pacifici
Published August 15, 1999
Citation Information: J Clin Invest. 1999;104(4):503-513. https://doi.org/10.1172/JCI7094.
View: Text | PDF
Article

Estrogen decreases TNF gene expression by blocking JNK activity and the resulting production of c-Jun and JunD

Abstract

Central to the bone-sparing effect of estrogen (E2) is its ability to block the monocytic production of the osteoclastogenic cytokine TNF-α (TNF). However, the mechanism by which E2 downregulates TNF production is presently unknown. Transient transfection studies in HeLa cells, an E2 receptor–negative line, suggest that E2 inhibits TNF gene expression through an effect mediated by estrogen receptor β (ERβ). We also report that in RAW 264.7 cells, an E2 receptor–positive murine monocytic line, E2 downregulates cytokine-induced TNF gene expression by decreasing the activity of the Jun NH2-terminal kinase (JNK). The resulting diminished phosphorylation of c-Jun and JunD at their NH2-termini decreases the ability of these nuclear proteins to autostimulate the expression of the c-Jun and JunD genes, thus leading to lower production of c-Jun and JunD. The consequent decrease in the nuclear levels of c-Jun and JunD leads to diminished binding of c-Jun/c-Fos and JunD/c-Fos heterodimers to the AP-1 consensus sequence in the TNF promoter and, thus, to decreased transactivation of the TNF gene.

Authors

Sunil Srivastava, M. Neale Weitzmann, Simone Cenci, F. Patrick Ross, Stuart Adler, Roberto Pacifici

×

Figure 4

Options: View larger image (or click on image) Download as PowerPoint
ERβ specifically mediates an inhibitory effect of E2 on TNF gene express...
ERβ specifically mediates an inhibitory effect of E2 on TNF gene expression. (a) HeLa cells were transfected with a reporter plasmid that contained a luciferase gene under the transcriptional control of an ERE driven by a minimal promoter, and treated with either E2 or control vehicle as described for the RAW 264.7 cells. Luciferase activity was normalized to β-galactosidase activity to correct for variability in transfection efficiency and expressed as normalized luciferase activity. Mean ± SEM from 1 representative experiment. *P < 0.05 vs. untreated cells. (b) HeLa cells were pretreated with E2 for 24 hours, and cotransfected with TNF/CAT construct containing the 2.2-kb 5′ promoter region plus 1 kb of the 3′UTR and either ERα or ERβ expression vectors. Cells were then treated with E2 and IL-1 and TNF for 12 hours, as described in the text. The cells were subsequently lysed and assayed for CAT and β-galactosidase activities as described in Methods. Mean ± SEM of 3 experiments. *P < 0.05 vs. untreated cells.