Role of chemerin/CMKLR1 in the maintenance of early pregnancy.

Chemerin is a cytokine that attracts much attention in the reproductive process. This study aimed to explore the effects of chemerin and its receptor chemokine-like receptor 1 (CMKLR1) on the maintenance of early pregnancy. The expression levels of chemerin and CMKLR1 in the decidua tissues of 20 early normal pregnant women and 20 early spontaneous abortion women were examined by Western blot and real-time polymerase chain reaction analyses. CMKLR1 receptor antagonist (α-NETA) was then intrauterinely injected into normal pregnant mice model to assess its effect on the outcome of pregnancy and the phosphorylation rate of ERK1/2 in decidua tissues.We found that the expression level of chemerin in women who had experienced early spontaneous abortion was lower than in those who had experienced normal early pregnancy (P < 0.01); conversely, CMKLR1 expression was higher in the former than in the latter (P < 0.01). In a pregnant-mouse model, the embryo resorption rate of α-NETA group was higher than that in the negative control group (61.5% vs. 10.8%) (P < 0.001). Compared with the control group, ERK1/2 phosphorylation in decidua tissues decreased in the α-NETA-treated group (P < 0.01). These results suggested that the inhibition of the chemerin/CMKLR1 signaling pathway can lead to the abortion of mouse embryos, and that chemerin/CMKLR1 may play an important role in the maintenance of early pregnancy possibly by regulating ERK1/2 phosphorylation.