Expression Of TLR2 And TLR4 And The Relationship With Unexplained Recurrent Spontaneous Abortion

Objective: Unexplained recurrent spontaneous abortion (URSA) means the exclusion of genetic, anatomical, endocrine, infectious, autoimmune outside of these five causes of recurrent spontaneous abortion (RSA). URSA is most closely connected with the immunization. Maternal-fetal interface must resist the foreign invasion of pathogenic micro-organisms to make the immune response, at the same time it must be allowed as a semi-antigen embryo implantation and fetal growth and development-immune tolerance, to complete its breeding capabilities. Regulation of maternal-fetal interface, the maintenance of immune balance may play an important role in normal pregnancy. Once the immune balance is damaged, the embryo will be aborted subjected to the immune attack. If we can find a number of common factors among the immunological maintenance mechanisms of maternal-fetal interface, and conduct a specific intervention, improvement in patients with URSA prognosis can be expected. Toll receptor (TLR), which is newly discovered, is a critical innate immune receptors--a type of I transmembrane receptor. Different TLR recognizes different ligands, through the signal transduction pathway, playing different biological functions, playing an important role in regulating inflammation and immune responses. TLR2 and TLR4 are the representative receptors of all the TLRs family, expressing in placental trophoblast cells. Activation of TLR2 and TLR4 can induce a strong immune response, which can help the body resist the original microbial infection or tissue damage. But if the immune response is too strong, it will also take adverse effects. The balance of Th1-type cytokines and Th2-type cytokine (Th1/Th2) maintenance of normal pregnancy plays an important role in balance. If they are broken, a series of pathophysiological changes and miscarriage will be caused. Activation of TLR2 and TLR4 will release a large number of Th1-type cytokines, and result in placental vascular endothelial cell injury. Then it may have a direct impact on the immune balance maternal-fetal interface, thus URSA occurs. It reminds us: TLR2, TLR4/NF-KB signaling pathway is likely to be a critical approach in the procedure where URSA occurs. In this study, by detecting the TLR2, TLR4 in the expression of villi and decidua of URSA and early pregnancy, we can preliminarily study the role of TLR2 and TLR4 in the genesis and development of URSA. Meantime, by detecting serum level of Th1-type cytokine (TNF-α) and Th2 type cytokines (IL-10), we can preliminarily learn the available ways of TLR2 and TLR4 in the occurrence of URSA.Methods: Prospective study Outpatients of Obstetrics and Gynecology at the Medical College of Zhejiang University and Hangzhou First People's Hospitalin 2008-2009. Put those women whose ages are between25-35 year's old, and gestational age <12 weeks together as a study group. For those URSA patients who have been spontaneously aborted for≥3 times, we regard this group as study group. While for those healthy patients who have normal reproductive history, demanding induced abortion in early pregnancy termination of pregnancy we will distinguished them as a control group. We select both URSA patients (study group) and healthy pregnant patients (control group) with 20 cases. By immunohistochemical staining we detect the expression of TLR2 and TLR4 in villi and decidua to compare the different expression of TLR2 and TLR4 in Villi and decidua of URSA and early pregnancy; At the same time with the double-antibody sandwich ELISA assay we detect serum concentration of Th1-type cytokine (TNF-α) and Th2 type cytokines (IL-10), to compare the concentration differences of serum TNF-αand IL-10 of URSA and early pregnancy. Results: 1. No significant difference between Study group and contrast group's age, gestational age and pregnancy time; 2. Localization of TLR2 and TLR4 expression: villi was mainly expressed in the cytoplasm of syncytiotrophoblast and membrane, while decidua was mainly expressed in glandular epithelial cells of cytoplasm and membrane. 3. No significant difference between expression of TLR2 in the cytoplasm and the membrane of villous trophoblast cells in two groups, no statistically significant difference (p>0.05); Expression of TLR2 in the cytoplasm and the membrane of decidual glandular epithelial cells was not significant different, no statistically significant difference (p>0.05); 4. Compared with contrast group, expression of TLR4 in the cytoplasm and the membrane of trophoblast cells in study group was significantly increased, the difference was statistically significant (p<0.05); Compared with control group, expression of TLR4 in the cytoplasm and the membrane of decidual glandular epithelial cells was significantly increased, the difference was statistically significant (p<0.05). 5. Compared with the control group, concentration of TNF-αin the study group was significantly higher, the difference was statistically significant (p<0.05); while the concentration of IL-10 was no significant difference (p> 0.05).Conclusions: 1.TLR2 and TLR4 were expressed in villi and decidua duringpregnancy.2. Expression level of TLR4 in villi and decidual of URSA patients was significantly higher, TLR4 may be involved in the pathogenesis of URSA. 3. TLR4 is more closely involved in the immune response of the pathogenesis of URSA, the relationship between TLR4 and URSA may be more closely than TLR2. As a trigger key component of URSA, expression of TLR4 in villi and decidua may be one of the key to occur URSA. 4. With TNF-αand URSA closer, TLR4 may be released of excessive levels of Th1-type cytokines, leading to Thl/Th2 imbalance, giving rise to URSA.