Estrogen receptor- mediates human multidrug resistance associated protein 3 induction by 17-ethynylestradiol. Role of activator protein-1
Previously, we have demonstrated that 17α-ethynylestradiol (EE) induces rat multidrug-resistance associated protein 3 (Mrp3, Abcc3) expression transcriptionally through estrogen receptor-α (ER-α) activation. We explored the effect of EE on MRP3 expression of human origin. HepG2 cells were transfecte...
| Autores: | , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2013 |
| País: | Argentina |
| Institución: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/6038 |
| Acceso en línea: | http://hdl.handle.net/11336/6038 |
| Access Level: | acceso abierto |
| Palabra clave: | ETHYNYLESTRADIOL ER MRP2 AP-1 https://purl.org/becyt/ford/3.1 https://purl.org/becyt/ford/3 |
| Sumario: | Previously, we have demonstrated that 17α-ethynylestradiol (EE) induces rat multidrug-resistance associated protein 3 (Mrp3, Abcc3) expression transcriptionally through estrogen receptor-α (ER-α) activation. We explored the effect of EE on MRP3 expression of human origin. HepG2 cells were transfected with ER-α and incubated with EE (1–10–50 μM) for 48 h. MRP3 protein and mRNA levels were measured by Western blotting and Real time PCR, respectively. EE up-regulated MRP3 protein and mRNA at 50 μM only in ER-α(+)-HepG2 cells. The in silico analysis of mrp3 promoter region demonstrated absence of estrogen response elements, but showed several Ap-1 binding sites. We further evaluated the potential involvement of the transcription factors c-JUN and c-FOS (members of Ap-1) in MRP3 up-regulation. ER-α(+) HepG2 cells were incubated with EE and c-FOS and c-JUN levels measured by Western blotting in nuclear extracts. EE up-regulated only c-JUN. Experiments of overexpression and knock-down of c-JUN by siRNA further demonstrated that this transcription factor is indeed implicated in MRP3 upregulation by EE. Co-immunoprecipitation assay demonstrated that EE induces c-JUN/ER-α interaction, and chromatin immunoprecipitation assay showed that this complex is recruited to the AP-1 binding consensus element present at the position (−1300/−1078 bp) of human mrp3 promoter. We conclude that EE induces MRP3 expression through ER-α, with recruitment of ER-α in complex with c-JUN to the human mrp3 promoter. |
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