Analysis of gene expression and preliminary study of methylation about 11ß-HSD2 gene in placentas of Chinese pre-eclampsia patients of Han ethnicity.

ABSTRACT

AIMS: The aim of this study was to determine the promoter methylation status of type 2 isoform of 11ß-hydroxysteroid dehydrogenase (11ß-HSD2) and its regulatory correlation with 11ß-HSD2 gene expression in placentas of pre-eclampsia (PE) patients of Chinese Han ethnicity. MATERIAL AND METHODS: The pathological features of placental tissues were studied using hematoxylin-eosin staining and immunohistochemical staining. The 11ß-HSD2 mRNA and protein expressions were detected by real-time polymerase chain reaction and Western blotting. The methylation of the 11ß-HSD2 promoter sequence was examined by bisulfite sequencing polymerase chain reaction. RESULTS: Trophoblast hyperplasia and discontinuous syncytial layer were observed in the PE group, and the 11ß-HSD2 was distributed irregularly and its immunoreactivity was weakened distinctly. The expressions of 11ß-HSD2 mRNA and protein decreased significantly in the PE group compared with the control group. Unexpectedly, almost no 11ß-HSD2 methylation was detected in PE placental tissue (two fragments, 0.6% vs 0%) or normal placental tissue (1% vs 0.6%). No significant difference in 11ß-HSD2 promoter methylation was found between the two groups. CONCLUSIONS: The 11ß-HSD2 expression decreased in PE women of Chinese Han ethnicity, but was not interrelated with the promoter methylation status.