Increased Toll-Like Receptor-Myeloid Differentiation Factor 88 Expression at the Maternal-Fetal Interface Is Associated with Spontaneous Abortion.

Aims: Toll-like receptors (TLRs) form a group of pattern recognition receptors that play a major role in maintaining innate host immunity. Myeloid differentiation factor 88 (MyD88) is an adaptor molecule that is essential for signaling via the TLR family. To analyze the mechanism of the imbalance in the innate immune system mediated by TLRs-MyD88 in spontaneous abortion, we detected the expression of TLR-2, TLR-4, TLR-7, and MyD88 in placentae and deciduas.

Methods: The expression of TLR-2, TLR-4, TLR-7, and MyD88 in the placentae and deciduas of abortion-prone mice (n = 10) and normal pregnant mice (n = 10) were analyzed by immunochemistry, western blot, and real-time polymerase chain reaction.

Results: There were higher protein expression levels of TLR-2, TLR-4, TLR-7, and MyD88 in the placentae and deciduas in the abortion-prone group than in the normal pregnant group. However, TLR-2, TLR-4, and TLR-7 showed lower gene expression, while MyD88 manifested higher gene expression in placentae and deciduas of abortion-prone mice matings.

Conclusions: TLR-2, TLR-4, TLR-7, and MyD88 were expressed in the placenta and decidua of both the abortion-prone pregnant and normal pregnant mice. The overexpression of TLRs may excessively activate the innate immune system mediated by MyD88, which is considered to be related to the pathogenesis of spontaneous abortion.