Abstract

LOMBARDO, DM et al. Disruption of junctions mediated by cadherins. Role in apoptosis of porcine ovarian granulosa cells. InVet [online]. 2010, vol.12, n.1, pp.91-101. ISSN 1668-3498.

The normal physiology and the dynamics of the reproductive tissue depends in great measure of an appropriate contact cell to cell, which is mediated by proteins of the cadherins family, molecules Ca⁺⁺ dependent such as the E and N Cadherin. In these circumstances, the atresia process for apoptosis of the granulosa cells (CG), it could be related with the loss of this cellular contacts. In this work, the objective was to establish the relationship among the loss of the contacts Ca⁺⁺ dependent with the integrity and the apoptosis of the CG. Considering the importance of cadherin (E-CAM and N-CAM) in the development and follicular atresia, which most of the follicles begin to degenerate in the early antral stage and considering the atresia as a stage-dependent process was raised identify and localize the expression of these molecules in the ovary of adult pig, trying to discriminate and relate the different stages of follicle genesis. En antral follicles, those cells with an apparent loss of integrity (lack of cohesion with neighboring cells or disaggregated antral cell layer), did not identify any other label for antibodies in question. In order to correlate the same process in vitro, the study model was a cellular primary culture of porcine CG obtained by aspiration of antrals follicles, which were treated with EGTA, to obtain the disruptión of the homophilic juntions. The treatments were made with EGTA 9 nM and 100 nM and without EGTA, both treatment at different times of induction 6, 12 and 24 hours. In each case, the apoptosis index (AI) was determined by DAPI and TUNEL techniques. Also, was carried out a quantitative evaluation by analysis of images of the expression of Bax by inmuno cytochemical. To different concentration of the inductor, the treatments with serum demonstrated a bigger AI to 9 nM (1,27; 2,58 and 1,38 to 6, 12 and 24 hs respectively). The activation was significant in the treatments of 12 hs with serum (p=0,05) respect to the control. To concentrations of 100 nM the AI didn't demonstrate significant differences of activation. The quantitative determination of the expression of Bax and for ICQ validates the previous results.

Keywords : Granulosa cells; Apoptosis; E-cadherine; Ovary; Swine.

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