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

## TL;DR

This study shows that TNF-α reduces ID2 levels in trophoblast cells, which may affect pregnancy outcomes like preeclampsia.

## Contribution

The paper reveals a dose-independent downregulation of ID2 by TNF-α and links it to p63 and NF-κB pathways in trophoblast cells.

## Key findings

- TNF-α decreases ID2 expression in a dose-independent manner in HTR8 cells.
- TNF-α increases p63 expression and cell viability, which is blocked by NF-κB inhibitors.
- The effects of TNF-α on ID2 are not mediated by NF-κB or MAPK pathways.

## Abstract

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.

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.

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.

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.