In-Vitro Effects of Bisphenol a in Immature GnRH Neurons

Presentation Number: SAT 256
Date of Presentation: April 1st, 2017

Marina Olga Fernandez*, Paula Andrea Arocena, Victoria A Lux-Lantos and Carlos Libertun
Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina

Abstract

Bisphenol A, (BPA), a component of polycarbonate plastics, epoxy resins and polystyrene found in many common products, is an endocrine disruptor that alters several functions in different species, including rats, mice and humans. Previously we described the effects of neonatal exposure to BPA on the hypothalamic-pituitary-gonadal axis of female rats (1;2). In this study we analyzed the in vitro effects of BPA in immature GnRH neurons, GN11 cells, developed by Dr. Susan Wray (NIH), and provided by Dr. Pamela Mellon (UCSD), USA.

We studied cell proliferation using a Non-Radioactive Cell Proliferation Assay, MTS (Promega, WI, USA) in response to BPA (1x10-9 and 1x10-7M, Sigma Aldrich, MO, USA), estradiol (E2, 1x10-9and 1x10-7M, Sigma), the estrogen antagonist ICI 182780 (ICI, 1x10-6M, Sigma) and kisspeptin-10 (Kiss, 1x10-9M, Phoenix Pharmaceuticals Inc., CA, USA). Results were recorded as Abs490/Abs490(Control), presented as Mean±SE and analyzed by ANOVA with a Fisher posttest (Statistica, StatSoft, OK, USA).

Twenty four h treatment with BPA and E2 increased cell proliferation relative to control (Control: 1±0.1, BPA 1x10-7M: 1.4±0.1, BPA 1x10-9M: 1.6±0.3, E2 1x10-7: 1.7±0.2, E2 1x10-9:1.6±0.2; BPA, E2 different from Control, n=9, p<0.05). ICI did not have any effect on cell proliferation on its own (Control: 1±0.1, ICI: 1.3±0.1, n=9, ns), but it blocked BPA 1x10-9M effect (Control: 1±0.1, BPA 1x10-7M: 1.4±0.1, BPA 1x10-9M: 1.6±0.3, ICI-BPA 1x10-7M: 1.4±0.1, ICI-BPA 1x10-9M: 1.2±0.1; ICI-BPA 1x10-9M different from BPA 1x10-9M, n=9, p<0.05). ICI also reduced E2 1x10-9-induced proliferation to near control values, although not attaining statistical significance (Control: 1±0.1, E2 1x10-7: 1.7±0.2, E2 1x10-9:1.6±0.2, ICI- E2 1x10-7: 1.7±0.3, ICI- E2 1x10-9: 1.3±0.2, n=9). Kiss increased cell proliferation and this effect was not modified by either BPA or E2 (Control: 1±0.1, Kiss: 1.5±0.2, Kiss-BPA 1x10-7M: 1.4±0.1, Kiss-BPA 1x10-9: 1.5±0.1, Kiss-E2 1x10-7M: 1.8±0.3, Kiss-E2 1x10-9M: 1.7±0.2; Kiss, Kiss-BPA, Kiss-E2 different from Control p<0.05, n=9).

To our knowledge, our results showed for the first time a direct effect of BPA on GN11 cell proliferation that was in part blocked by the estrogen antagonist ICI 182780. Kiss also exerted a proliferative effect that was not modified by either the endocrine disruptor or the natural estrogen. More studies are underway to further dissect the mechanisms involved.

 

Nothing to Disclose: MOF, PAA, VAL, CL