Bisphenol A diglycidyl ether (BADGE) is a PPARgamma agonist in an ECV304 cell line

Abstract

Peroxisome proliferator activated receptors (PPAR)s are nuclear transcription factors of the steroid receptor super-family. One member, PPARgamma, a critical transcription factor in adipogenesis, is expressed in ECV304 cells, and when activated participates in the induction of cell death by apoptosis. Here we describe a clone of ECV304 cells, ECV-ACO.Luc, which stably expresses a reporter gene for PPAR activation. ECV-ACO.Luc respond to the PPARgamma agonists, 15-deoxy-Delta(12,14) PGJ(2), and ciglitizone, by inducing luciferase expression. Furthermore, using ECV-ACO.Luc, we demonstrate that a newly described PPARgamma antagonist, bisphenol A diglycidyl ether (BADGE) has agonist activities. Similar to 15-deoxy-Delta(12,14) PGJ(2), BADGE induces PPARgamma activation, nuclear localization of the receptor, and induces cell death.

Figure 1

Characterization of the induction of luciferase by PPAR agonist in ECV-ACO.Luc, a cell line which stably expresses a reporter gene for PPAR activation. Cells at 15–20% confluence in 24-well plates were treated for 24 h with (A) the PPARγ agonists, 15d-PGJ₂ (15d; 1 μM) and ciglitizone (Cig; 30 μM), or the PPARα, and -δ agonist carbaprostacyclin (Carb; 30 μM), or (B) with BADGE (10–100 μM). The results represent fold increase of luciferase activity induced by ligands compared to untreated cells, and are expressed as mean±s.e.mean for n=6–12. ^*Denotes significance (P<0.05) of drug treatment compared to control by one sample t-test.

Figure 2

Effect of PPAR agonists and BADGE on ECV-ACO.Luc viability. ECV-ACO.Luc were treated with 15d-PGJ₂ (0.1–10 μM), ciglitizone (1–100 μM), or BADGE (1–300 μM) for 24 h, and cell viability measured by MTT assay. Results, expressed as per cent of control, are the mean±s.e.mean from 9–15 determinations from 3–5 separate experiments.

Figure 3

PPAR expression and activation in ECV-ACO.Luc. Immunofluorescence micrographs of PPARγ in ECV-ACO.Luc under control culture conditions (A), and following treatment with either 3 μM 15d-PGJ₂ (B), or 30 μM BADGE (C) for 24 h. In the absence of primary antibody against PPARγ (D), no specific staining was observed. This data is representative of n=3 separate experiments.