NEONATAL EXPOSURE TO A GLYPHOSATE BASED HERBICIDE ALTERS THE DEVELOPMENT OF THE RAT UTERUS

GUERRERO SCHIMPF M; MILESI M.; INGARAMO P. I.; MUÑÓZ DE TORO M; LUQUE EH; VARAYOUD J

Natal

Congreso; 9th Congress of Toxicology in Developing Countries (CTDC9) and XIX Congresso Brasileiro de Toxicologia; 2015

NEONATAL EXPOSURE TO A GLYPHOSATE BASED HERBICIDE ALTERS THE DEVELOPMENT OF THE RAT UTERUS Guerrero Schimpf, ML.; Milesi M.M.; Ingaramo P.I., Muñoz-de-Toro M., Luque E.H., Varayoud J.Instituto de Salud y Ambiente del Litoral (ISAL), Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral ? Consejo Nacional de Investigaciones Científicas y Técnicas, Santa Fe, Argentina.Introduction: Glyphosate-based herbicides (GBH) are extensively used to control weeds on both cropland and non-cropland areas. In vitro and in vivo studies have reported endocrine disrupting effects and male reproductive toxicity at puberty and adulthood caused by GBH exposure. However no reports are available regarding its effects on the development and performance of the female reproductive tract.Objective: To evaluate the effects of neonatal exposure to a GBH on uterine morphology, proliferation and expression of proteins that regulate uterine organogenetic differentiation in rats.Material and Methods: Female Wistar pups received saline solution (control, C) or an environmental relevant dose of commercial formulation of glyphosate (GBH, 2 mg/kg) by sc injection every 48 h from postnatal day (PND) 1 to PND7. Rats were sacrificed on PND8 (neonatal period) and PND21 (prepubertal period) to evaluate acute and short-term effects, respectively. The uterine histomorphology was evaluated in hematoxylin and eosin stained sections. The epithelial and stromal immunophenotypes were established by assessing the expression of luminal epithelial protein (cytokeratin 8; K8), stratified epithelial proteins (p63 and pan cytokeratin -K1, -K5, -K10 and -K14); and vimentin (a cytoskeletal protein expressed in mesenchymally-derived cells) by immunohistochemistry (IHC). The uterine cell proliferation was detected by the expression of Ki-67 protein. In addition, we evaluated the expression of estrogen receptor alpha (ERa), progesterone receptor (PR) and Hoxa10 by IHC in all uterine compartments (LE: luminal epithelium, GE: glandular epithelium, SS: subepithelial stroma, M: myometrium), to investigate changes in proteins that regulate uterine organogenetic differentiation.Results and Discussion: The GBH-exposed uteri showed morphological changes. The most relevant change was the luminal epithelial hyperplasia (75% of animals on PND8 and 37.5% on PND21). The epithelial cells showed a positive immunostaining for K8 and the stromal cells for vimentin. GBH-treated group showed an increase cellular proliferation in the LE and SS on PND8, without changes on PND21. In addition, the uterine organogenetic differentiation was affected at both ages. An induction of PR and Hoxa10 was detected in all cellular compartments of GBH-treated rats on PND8 and ERa was also up regulated in the SS. The deregulation of PR and Hoxa10 persisted on PND21.Conclusions: Neonatal exposure to GBH disrupts the postnatal uterine development and alters the expression of proteins involved in uterine organogenetic differentiation at the prepubertal period. All these changes may alter the functional differentiation of the uterus, affecting the female fertility and/or promoting the development of neoplasias.Acknowledgements: Financial support from the Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT, PICT 2011-1491), CONICET (PIP 2011, 11220110100494) and the Universidad Nacional del Litoral (CAI + D 2011, 501 20110100423 LI).Keywords: Glyphosate-based herbicides, Uterus, Estrogen receptor alpha, Progesterone receptor, Hoxa10.