STAT3 signaling pathway is involved in the pathogenesis of miscarriage.

Introduction: The STAT3 signaling pathway plays an important role in the migration and invasion of villous trophoblast cells. In early miscarriage, the activation of STAT3 has been confirmed to decline, but its effect in early pregnancy has not received much attention.

Methods: The number of trophoblast cells were detected by HE staining in 30 cases of earlymiscarriage, 20 cases of recurrent miscarriage and 30 cases of control group.The protein levels of CyclinD1, VEGF, VEGFR1, Ki67, CD34 and phosphorylated STAT3 in three groups weredetected by immunohistochemistry or Western blot.Consistently, the mRNA levels of them weredetected by qPCR. The expression of STAT3 signaling pathway on trophoblast cells were evaluated in HTR-8/SVneo cell treated by AG490. Additionally, we established the situation of AG490-induced STAT3 signaling pathway inhibited in HTR-8/SVneo cell as well.

Results: HE staining showed that the number of trophoblast cells in the two study groups were significantly lower than that in the control group. The expression of STAT3 and its down stream target gene, such as CyclinD1, VEGF were significantly downregulated in abortion tissues (villi and decidua) in patients with early miscarriage. In vitro, AG490 inhibited the growth of trophoblast cells and promoted apoptosis of them by inhibiting STAT3 signaling pathway.

Discussion: The STAT3 signaling pathway might be involved in the pathogenesis of earlymiscarriage.However, further experiments are still needed to verify whether inhibitors of the STAT3 pathway can be used as drug treatment targets for spontaneous abortion.