Endocrine Abstracts

Introduction: Visfatin belongs to adipokines, i.e. hormones produced mainly by adipose tissue; its expression and role have been described in many organs, where it regulates energy metabolism, insulin resistance and inflammatory reactions. Moreover, the level of visfatin changes during pregnancy and in obese women and those with obesity related pregnancy pathologies: preeclampsia (PE), gestational diabetes (GDM) or intrauterine growth restriction (IUGR) its level increases. There is no data about the role of adipokine in placenta so the aim of this study was to: 1) determine the expression and immunolocalization of visfatin in the trophoblast cell lines JEG-3 and BeWo, as well as in the maternal and fetal parts of placentas from normal and PE, GDM and IUGR complicated pregnancies; 2) examine the effect of: estradiol (E₂), progesterone (P₄), human chorionic gonadotropin (hCG) and insulin (INS) on visfatin level in JEG-3.

Materials and Methods: To study the mRNA (real time PCR), protein (Western blot) expression and immunolocalization (immuno -cytochemistry, -histochemistry) of visfatin, JEG-3/BeWo were cultured in time-dependent manner, while fragments of terminal placentas were collected after delivery. Furthermore, the effect of: E₂ (1, 10, 100 nM), P₄ (1, 10, 100 nM), hCG (0.1, 1, 10 ng/ml), INS (10, 50, 100 ng/ml) on visfatin protein expression (Western blot) and concentration (ELISA) was examined. Next, the involvement of signaling pathways of extracellular signal-regulated kinase (ERK 1/2), transcription factor NF kappa B (NF-κB) and receptors (PR, GPR30, ER, LHCGR, INSR) in visfatin regulation was analyzed. Statistical analysis was performed in Graph Pad Prism 7, using one-way ANOVA and Tukey’s test (n=5, P<0.05).

Results: We demonstrated the mRNA and protein expression of visfatin in JEG-3/BeWo cells and in normal/pathological placentas. Our studies showed the immunolocalization of visfatin in cytoplasm of both cell lines, syncytiotrophoblasts of placenta fetal part and capillary epithelium of maternal part while in the pathologies additionally in decidual cells. Moreover, we explored a stimulatory effect of all tested hormones on visfatin level in JEG-3 with the involvement of specific signaling pathways.

Conclusion: Differences in the localization of visfatin in the maternal part of normal and pathological placentas, suggested that adipokine may be a potential marker for pregnancy disorders diagnosis. In addition, variable level of visfatin during individual trimesters may be the result of pregnancy hormones, which stimulate its level in the human placenta cells.

Funding: Diamond Grant IX 0110/DIA/2020/49; Excellence Initiative - Jagiellonian University ‘Visibility and Mobility Module’.