The Expression of Nuclear Factor-kappaB in the Placental Tissue with Preeclampsia

Yoo, Seung Chul; Byun, Young Ji; Yang, Jeong In; Joo, Hee Jae; Kim, Haeng Soo; Ryu, Hee Sug

Abstract

OBJECTIVE
The aim of this study is to ascertain the differences in NF-kappaB (Nuclear Factor-kappa B : p50) activity between the placental tissues of preeclampsia and normal pregnancy, and to certify that the circulating lipid peroxides is increased in preeclamptic women.
METHODS
Placental tissues were obtained from preeclamptic (n=33) and normal pregnancies (n=21) with no other medico-surgical illness or obstetric complications, delivered by cesarean section without labor. The activities of NF-kappaB and IkappaBalpha (Inhibitory factor kappaBalpha) on syncytiotrophoblast, cytotrophoblast, endothelium, extravillous cytotrophoblast, and decidua were separately measured by immunohistochemical staining using tissue microarray technique. Malondialdehyde assay was used to evaluate the oxidative stress, measuring lipid peroxide levels on each sample. Mann-Whitney test was done for statistical analysis of the data.
RESULTS
Nuclear staining of NF-kappaB (p50) was seen more intensively within the extravillous cytotrophoblast of preeclampsia group compared with the control group (p<0.05). The immunoreactivity of NF-kappaB (p50) was also detected in cytotrophoblasts, syncytiotrophoblasts, endothelium, and decidua, but showing no statistical difference between two groups. IkappaBalpha was strongly expressed in both groups but there was no statistically significant between two gropups. Preeclamptic group showed significantly increased circulating lipid peroxide levels compared to normal pregnancy group (1.22+/-0.79 nmol/mL vs 0.41+/-0.12 nmol/mL, p<0.05).
CONCLUSION
The expression of NF-kappaB is significantly increased in extravillous cytotrophoblast of preeclamptic women compared to normal pregnancy, and may be associated with increased levels of circulating lipid peroxide. These findings might help us to understand the pathologic mechanism of preeclampsia and further study should be done for effects of NF-kappaB on implantation.