Neonatal exposure to a glyphosate-based herbicide alters cell proliferation by disrupting the expression of development-related molecules in the ewe lamb uterus

ALARCÓN R.; INGARAMO P; MILESI, MARÍA M.; DIOGUARDI, GISELA H.; RIVERA, OSCAR E.; MUÑOZ-DE-TORO, M; LUQUE EH

Congreso; REUNION CONJUNTA SAIC . SAFE . SAB . SAP 2019; 2019

SOCIEDAD ARGENTINA DE INVESTIGACION CLINICA

The misuse of Glyphosate-based herbicides (GBHs) has increased the concern about its effects on health. Recently, we reported in ewe lambs, that the postnatal exposure to a low dose of GBH decreased the uterine cell proliferation on postnatal day 45 (PND45), regardless the oral or subcutaneous (sc) route. Here, we investigate whether postnatal GBH exposure alter the expression of molecules related with cell proliferation and uterine development. Frisone breed ewe lambs were sc exposed from PND1 to PND14 to saline solution (vehicle) or a low dose of a GBH (glyphosate at 2 mg/Kg/day). At PND45, uterine horns samples were collected for paraffin-embedding or stored at -80°C until mRNA extraction. Expression of Ki67 (cell proliferation marker), p27, and molecules involved in uterine development (ERα, PR, Wnt5a and -7a, 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 with uterine development, were assessed by RT-PCR. Cell proliferation decreased while the protein expression of p27 increased in all uterine compartments, luminal (LE) and glandular epithelia (GE), and in subepithelial stroma (SS);. The mRNA expression of IGFBP-3 increased in GBH-exposed lambs while no changes were observed in expression of IGFs or its receptor. 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 animals. Moreover, GBH exposure decreased the expression of Wnt5a and Wnt7a in GE and SS respectively, β-catenin expression in LE and GE, and decreased the Hoxa10 and Foxa2 expression in SS and GE, respectively. 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 involved in uterine development, which could compromise future reproductive performance.Keywords: ewe lambs; uterus; glyphosate; cell proliferation; development.