TNF-α-Induced Downregulation of ID2 in Human First Trimester Trophoblast Cells

Background and Objective: Low levels of Tumor Necrosis Factor-Alpha (TNF-α) support normal pregnancy, while elevated levels are linked to complications like preeclampsia by impairing trophoblast migration and invasion. The study investigates the effect of TNF-α on ID2, a protein associated with trophoblast proliferation, differentiation and stemness, using the HTR8/SVneo cell model. Materials and Methods: The HTR8 cells were treated with three different doses of TNF-α (1, 10 and 100 ng/mL) for 4 or 24 hrs. The mRNA and protein levels of ID2 were determined by qRT-PCR and western blot, respectively. Cell viability after exposure to three doses of TNF-α was assessed using the CCK-8 kit. Data are presented as Mean±SEM, analyzed using multifactorial ANOVA with post hoc Tukey-Kramer test in JMP 16.0 (SAS Institute, Cary, NC), considering p<0.05 as statistically significant. Results: Following exposure to three doses of TNF-α for 4 or 24 hrs, both transcriptional and protein levels of ID2 in HTR8 cells were decreased in a dose-independent manner,10 ng/mL of TNF-α had the greatest effects. Additionally, all three doses of TNF-α increased p63 expression as well. Inhibitors of NF-κB or MAPKs did not alter TNF-α-induced decrease in ID2 expression. All three doses of TNF-α increased cell viability to the same level and an inhibitor of IKK/NF-κB, BMS345541, abolished the survival-enhancing effects of the cytokine. Conclusion: The decrease in ID2 expression by TNF-α could be mediated by p63, while the increase in cell survival could be linked to NF-κB activation.