Trophoblast turnover’s study in placentas of women with diabetes mellitus in vitro infected with T. cruzi

Abstract

Abstract: 

The integrity of the placental trophoblast is maintained through the cytotrophoblast’s proliferation (CTB), fusion in the syncytiotrophoblast (STB), with controlled detachment of syncytial knots, a fundamental process for fetal development that is altered in diabetic placentas with greater susceptibility to infections. Trypanosoma cruzi (T. cruzi) can cause the congenital transmission of Chagas disease, altering the turnover of the human trophoblast in in vitro studies. Little is known about the trophoblast renewal process in diabetic and parasite-infected placentas. The aim of this work was to analyze in vitro the human trophoblast turnover process in placentas from diabetic women infected with T. cruzi. Human placentas at term from cesarean sections of clinically healthy women (control) and with diabetes (n = 6) were used, respecting ethical and legal aspects. The explants were co-cultured with 1x106 trypomastigotes of T. cruzi, Tulahuen strain, for 24 hours. In sections stained with H/E were quantified: number of syncytial knots,​​ perivillous fibrin and STB detachment’s areas (%). Immunohistochemistry was performed for Ki67 (proliferation of CTB) and Cytokeratin-7 (trophoblastic integrity). Fiji ImageJ was used for quantification. Statistics: ANOVA- Bonferroni test (p<0.05). A significant increase in the number of syncytial knots (91%; p = 0.0017), in intervillous fibrin deposits (97%; p = 0.0002) and in STB detachment (86.6%; p = 0.0075) was observed in infected diabetic placentas, compared to controls. The proliferation index (Ki67) increased significantly (52%) in infected diabetic placentas, compared to controls (p = 0.0047). While the expression of CTK7 decreased by 47.5% in diabetic placentas without infection, with respect to the control (p<0.0001), this difference being less in diabetics co-cultured with T. cruzi (15%). These results suggest that the dynamics of trophoblastic turnover is modified in diabetic and T. cruzi-infected placentas, altering the defense mechanisms of the placental barrier, which could further increase the probability of the parasite’s congenital transmission