Exposure to BPA disrupts wnt signaling pathway during postnatal differentiation of the oviduct in broad-snouted caiman (Caiman latirostris)

GALOPPO GH; LUQUE EH; KASS L; CANESINI G; MUÑOZ-DE-TORO M

Buenos Aires

Congreso; XVIII Jornadas Anuales de la Sociedad Argentina de Biología; 2016

Sociedad Argentina de Biología

Wnt molecules and β-catenin control postnatal female reproductivetract development through canonical (β-catenin -dependent) or non-canonical pathways.These molecules are sensitive to endocrine-disrupting compounds (EDCs) and theoviduct is a target organ of EDCs action. Our aims were to establish theontogeny of temporal and spatial expression patterns of wnt-5a, wnt-7a and β-catenin in C.latirostris oviducts from neonatal to pre-pubertal juvenile caimans, and toevaluate the effect of BPA early postnatal exposure. C. latirostris femalesraised in control conditions were euthanized at neonatal, early and latepostnatal or juvenile stages. Early postnatal caimans were injected (sc) twice,7 days apart, with 17-βestradiol (E2) (0.014 or 1.4ppm) or BPA (1.4 or 140 ppm) and euthanized 7 daysafter last injection. Oviductal wnt5a, wnt7a and β-catenin protein expressions wereassessed by immunohistochemistry. Epithelial wnt-7a and subepithelial wnt-5alevels increased as oviduct differentiation advances showing a mutual feedbackin the juvenile stage. Epithelial membrane-associated β-cateninexpression was not correlated to wnts levels. All the treatments, but BPA1.4ppm reduced wnt-7a expression, whereas E2 1.4ppm and BPA 1.4ppm decreasedwnt-5a levels. BPA 1.4ppm also modified CTNNB expression. Our results suggestthat postnatal development of C. latirostris oviduct is controlled bywnt signaling pathway and that early postnatal exposure to xenoestrogens coulddisrupt this process leading to histofunctional changes that could impairreproductive health later in life.