Expression of galectins and the Thomsen-Friedenreich antigen in normal, IUGR, preeclamptic and HELLP placentas – Galectin–1, Galectin–3 and TF expression
Aims: Galectin–1 (gal–1) and galectin–3 (gal–3), which are members of the mammalian β-galactoside-binding proteins, recognize preferentially Galβ1–4GlcNAc sequences of several cell surface oligosaccharides. In addition, gal–1 binds also to the Thomsen-Friedenreich (TF) antigen (Galβ1–3GalNAc-).
Material and Methods: Slides of frozen and paraffin embedded placental tissue of patients with IUGR, preeclamptic patients, HELLP patients and normal term placentas were incubated with monoclonal and polyclonal antibodies against gal–1, gal–3 and TF. Staining reaction was performed with the ABC reagent. Intensity of immunohistochemical reaction on the slides was analysed using a semi-quantitative score. Identity of galectin expressing cells was analysed by using a double immunofluorescence method.
Results: We demonstrated immunohistochemically that the expression of gal–1 and gal–3 on the extravillous trophoblast (EVT) is significantly up regulated in preeclamptic and HELLP placentas and unchanged compared to normal controls in IUGR placentas. The expression of TF is significantly up regulated in IUGR and preeclamptic extravillous trophoblast cells and unchanged in HELLP placentas compared to normal controls. In addition, the expression of gal–1 is significantly up regulated in decidual tissue of preeclamptic placentas and villous trophoblast tissue of HELLP placentas.
Conclusion: Our data showed that gal–1, gal–3 and TF were up regulated on the membrane of EVT in preeclamptic placentas. In addition, the expression of gal–1 is significantly up regulated in decidual tissue of preeclamptic placentas and villous trophoblast tissue of HELLP placentas. Taken together the results of this study we speculate that expression of both galectins and TF on the membrane of preeclamptic EVT and up-regulation of gal–1 in preeclamptic decidual cells may act anti-apoptotic on EVT and as suppressor of maternal T-cells.