[Effect of S100 calcium binding protein A12 on the pathogenesis of preeclampsia]

To investigate the role of S100 calcium binding protein A12 (S100A12) in the pathogenesis of preeclampsia.

Sixty patients with preeclampsia were recruited from March 2013 to December 2013 in the First Affiliated Hospital of Zhengzhou University. Among them, thirty cases were defined as the mild preeclampsia group and thirty cases were defined as the severe preeclampsia group. The other thirty healthy pregnant women were recruited in the healthy pregnant women group. The levels of S100A12 protein in maternal peripheral blood were detected by enzyme-linked immunosorbent assay (ELISA). Immunohistochemistry of streptavidin peroxidase biotin (SP) method was used to measure the protein expression of S100A12. The trophoblast cells were cultured in vitro with plasma from the three groups, and a blank control group was set up as well. Transwell was used to detect the cytotrophoblast invasion ability. Western blot was used to measure the protein expression level of receptor for advanced glycation end products (RAGE).

(1) The levels of S100A12 in maternal peripheral blood of patients with preeclampisa [mild group: (30.8±2.7) µg/L, severe group: (49.3±4.1) µg/L] were significantly higher than that of the control group [(15.8±1.4) µg/L]. In addition, compared with the mild preeclampsia group, the level of S100A12 in the severe preeclampsia group was significantly higher (P < 0.05). (2) Positive immunostaining of S100A12 was observed in the cytoplasm of cytotrophoblast, decidual cells and the placentas from the three groups. The positive rate in the mild preeclampisa group was 77% (23/30); in the severe preeclampsia group it was 93% (28/30); and in the healthy pregnant women group it was 23% (7/30). The positive rates of placenta in the mild and severe preeclampsia groups were significantly higher than that in the healthy pregnant women group (P < 0.05). In addition, compared with the mild preeclampsia group, the positive rate of immunostaining of S100A12 in the severe group was significantly higher (P < 0.05). (3) Cytotrophoblast invasion ability and the expression of RAGE in the mild preeclampsia group were 29.1±3.2 and 0.479±0.038, respectively; in the severe preeclampsia group they were 16.8±2.5 and 0.652±0.059; in the healthy pregnant women group they were 38.6±24.3 and 0.327±0.024; and in the blank control group they were 42.6±5.6 and 0.194±0.011. Cytotrophoblast invasion ability and the expression of RAGE protein in the mild and severe preeclampsia groups were significantly higher than those in the healthy pregnant women group and the control group(P < 0.05).

The expression of S100A12 increased in materal peripheral blood and placenta, and the receptor protein of S100A12 RAGE also had high expression. It suggested that the S100A12 may have some effect on the pathogenesis of preeclampsia.