IN OVO EXPOSURE TO ENDOSULFAN OR ATRAZINE INDUCES ALTERATIONS IN THE MOLECULAR MECHANISMS THAT GOVERN OVIDUCTAL ADENOGENESIS IN THE BROAD-SNOUTED CAIMAN (Caiman latirostris)

LUQUE, E.H.; GALOPPO, G.H.; TAVALIERI, Y.E.; MUÑOZ DE TORO, M.M.

Buenos Aires

Congreso; XXIII ANNUAL MEETING OF THE ARGENTINEAN BIOLOGY SOCIETY (SAB) ?; 2022

Sociedad Argentina de Biología

The formation of glands (adenogenesis) is a process that characterizes the postnatal development and differentiation of the oviduct in the broad-snouted caiman (Caiman latirostris). Previously we reported that the oviduct of prepubertal juvenile caimans expresses proteins involved in the differentiation and invagination of the epithelial cells, such as wnt-7a, wnt-5a, β-catenin and FoxA2. Additionally, we demonstrated that early exposure to endocrine disrupting compounds (EDCs) bisphenol A and 17β-Estradiol alters the expression of these proteins. While epithelial differentiation is necessary for adenogenesis, the process may not be carried out if the surrounding subepithelium, highly rich in collagen, is not adequately rearranged. Thus, the aims of this study were: a) to evaluate the expression of MMP2 and MMP9, proteins involved in the disaggregation and rearrangement of collagen fibers, and their inhibitors (TIMP1 and TIMP2), and the expression of β-catenin, a protein related to epithelial cells differentiation and invagination, in the oviduct of juvenile C. latirostris; b) to evaluate the effects of in ovo exposure to EDCs endosulfan (END; 20 ppm) and atrazine (ATZ; 0.2 ppm) on the expression of the mentioned proteins. Protein expression levels were evaluated by immunohistochemistry, quantified by image analysis and reported as integrated optical density arbitrary units, while mRNA expression levels were evaluated by qPCR and reported normalized by the expression of a housekeeping gene (L8). Our results show that the studied proteins are expressed in the oviduct of C. latirostris and may be playing an important role in oviductal adenogenesis by inducing changes at epithelial and subepithelial levels. In ovo exposure to END upregulated the expression of MMP2 (VEH 2.03 ± 1.85 vs. END 7.54 ± 5.94), MMP9 (VEH 1.26 ± 0.21 vs. END 3.66 ± 2.69) and TIMP1 (VEH 1.74 ± 0.78 vs. END 2.61 ± 0.67), and downregulated the expression of β-catenin in the glandular epithelium (VEH 8.92 ± 2.20 vs. END 6.13 ± 2.59); in ovo exposure to ATZ upregulated the expression of MMP9 (VEH 1.26 ± 0.21 vs. ATZ 2.92 ± 1.90). Our results demonstrate that the signaling pathways that govern oviductal adenogenesis are affected by exposure to END and ATZ. Changes in the differentiation of the oviduct may alter fertility and development of eggs in C. latirostris.