Exposure to Endocrine Disruptors Alters Inflammatory Markers in Mouse Hypothalamus In-Vivo and In-Vitro

CARLOS LIBERTUN; JUAN MANUEL RIAÑO GOMEZ; VICTORIA AR LUX-LANTOS; ELEONORA M. SORIANELLO; MARINA O. FERNANDEZ

Virtual

Congreso; SETAC Latin America 14th Biennial Meeting; 2021

SETAC Latin America

Bisphenol A (BPA) and Benzophenones (BPs) are endocrine disrupting chemicals (EDC).Previously, we showed that the in-vitro exposure to BPA, BP2 or BP3 decreased Kiss-induced GnRH gene expression in GT1-7 cells (Dr. Pamela Mellon, UCSD). In this study, we analyzed the in-vitro exposure of GT1-7 cells or isolated hypothalami from adult Balb/c males to BPA, BP2 or BP3 (Sigma, 1x10-9 M) on cytokine and glial fibrillary acidic protein (gfap) gene expression. After the incubations, RNA was extracted, reverse transcribed and qPCR performed using specific primers. The in-vivo exposure to BP2 or BP3 (250 µg/kg/day, orally, for five days) effects on gene expression in C57Bl/6 mice was also analyzed. Animals were sacrificed, brains rapidly dissected and placed in dry ice, and kept -80 ºC until processed. Micropunches that contained the Anteroventral Periventricular (AVPV) or Arcuate (ARC) nucleus were obtained and RNA was extracted, reverse transcribed and gene expression analyzed by qPCR. Results were expressed as Mean±SE andanalyzed by ANOVA using Statistica (Statistica v StatSoft Inc, USA).Twenty-four hour BPA increased il18 expression in GT1-7 cells (C=1.0±0.04, BPA=1.2±0.1, T-test p< 0.05, n=7), whereas neither BP2 nor BP3 had an effect. Twenty-four-hour BPA decreased il6 its expression relative to C and to 12-hour BPA, whereas BP3 increased the expression at 12-hours and decreased it after 24-hour stimulation (Repeated Measures Two-way ANOVA: BPA-24h different from DMSO-24h and BPA-12h p< 0.05, BP3-12h different from DMSO-12h and from BP3-24h p< 0.05, n=4). In the hypothalami, BPA increased gfap gene expression (C=0.8±0.2, BPA=1.7±0.4; T-test p< 0.05, n=9). In-vivo BP2 increased gfap gene expression in the AVPV (Control=1.3±0.2; BP2=2.5±0.4; BP3=1.5±0.4; BP2 different from Control, p< 0,05), but neither BP altered kiss1 expression in this nuclei. In the ARC, exposure to BP2 caused an increase in gfap expression that did not reach statistical significance (Control=0.9±0.2; BP2=1,7±0.5; BP3=1.2±0.2; ANOVA ns). Our results show that the EDC studied have the potential to alter the inflammatory state of GnRH neurons and to activate astrocytes inthe hypothalamus. More experiments are needed to dissect the mechanisms involved. Funding: CONICET, ANPCyT, UBA, International Society for Neurochemistry, Asoc. ORT Arg., Fund. R. Barón, Fund. Williams.