Neonatal exposure to a glyphosate-based herbicide alters cell proliferation in the uterus of ewe lambs

ALARCÓN R; DIOGUARDI G; LUQUE EH; MILESI MM; MUÑOZ-DE-TORO M; INGARAMO PI; RIVERA OE

Mar del Plata, Buenos Aires, Argentina

Congreso; LXIV Reunión Anual de la Sociedad Argentina de Investigación Clínica, Reunión de la Sociedad Argentina de Fisiología Experimental, Reunión de la Sociedad Argentina de Biología y Reunión de la Sociedad Argentina de Protozoología; 2019

Sociedad Argentina de Investigación Clínica, Sociedad Argentina de Fisiología Experimental, Sociedad Argentina de Biología y Sociedad Argentina de Protozoología

The increasing use of glyphosate-based herbicides (GBHs) raised concern about its effects on animal and human health. Recently, we reported that postnatal exposure of ewe lambs to a low dose of GBH decreased the uterine cell proliferation, regardless the oral or subcutaneous (sc) administration route. Here, we investigate the molecular pathways related to uterine cell proliferation affected by a postnatal GBH exposure. Frisone ewe lambs were sc exposed from PND1 to PND14 to vehicle (control) or a low dose of a GBH (glyphosate at 2 mg/Kg/day). At postnatal day 45 (PND45), uterine horns were collected for paraffin-embedding or stored at -80°C until mRNA extraction. Expression of Ki67 (as cell proliferation marker), p27 and proteins involved in uterine development (ERα, PR, Wnt5a, Wnt7a, β-catenin, Hoxa10 and Foxa2) were evaluated by immunohistochemistry. Gene expression of insulin-like growth factors (IGF-1, IGF-2, its receptor IGF-1R and the binding protein IGFBP-3), also related to uterine development, were assessed by RT-PCR. Cell proliferation decreased while p27 expression increased in all uterine compartments: luminal (LE) and glandular (GE) epithelia, subepithelial stroma (SS) and myometrium. The mRNA expression of IGFBP-3 was also increased in GBH-exposed lambs. In addition, lower ERα expression was observed in LE, GE and SS; while PR expression was lower in LE, and higher in GE and SS vs control. Moreover, GBH exposure decreased the expression of Wnt5a in GE and Wnt7a in SS; whereas β-catenin expression was lower in LE and GE. In GBH-exposed lambs a decreased Hoxa10 and Foxa2 expression in SS and GE, respectively, was also detected. To conclude, postnatal exposure to an environmental relevant dose of GBH decrease the cell proliferation in prepubertal sheep uterus by disrupting the expression of molecules responsible of uterine development. Our results suggest that GBH exposure could compromise reproductive performance in livestock animals.