Function and mechanism of histone demethytransferase Jmjd3 mediated regulation of Th1/Th2 balance through epigenetic modification in pre-eclampsia

Abstract

Objective: To observe the expression level of histone demethyltransferase Jmjd3 in patients with pre-eclampsia (PE), and to investigate the possible mechanism of its epigenetic modification in regulating Th1/Th2 imbalance in PE patients. Methods: The mRNA levels of histone demethyltransferase Jmjd3 from peripheral blood mononuclear cells (PBMC) of PE patients and normal pregnant women were detected by RT-PCR. Peripheral serum IFN-γ and IL-4 were detected by ELISA. RT-PCR was used to detect the mRNA levels of Jmjd3, Tbx21 and Cxcr3 in the spleen of PE and control mice. Immunomagnetic beads were used to sort out the initial CD4+ T cells in the spleen of control and PE mice. Western blot was used to detect H3K27me1 and H3K27me3 levels. ChIP analysis was used for H3K27me3 demethylation modification in spleens of PE mice. Results: Compared with normal pregnant women, the mRNA level of Jmjd3 in PBMC of PE patients was significantly increased, the level of IFN-γ in serum was significantly increased, and the level of IL-4 was significantly reduced (P<0.01). Compared with normal control mice, the mRNA level of Jmjd3 in the spleen of PE mice was significantly increased, and the expression of Tbx21 and Cxcr3 was significantly increased in PE mice (P<0.01); the H3K27me3 level of CD4+ T cells in PE mice was significantly reduced (P<0.05), but H3K27me1 was not changed. ChIP analysis showed that CD4+ T cells H3K27me3 in PE group mice were in the Ifng promoter region, compared with control mice. Recruitment was significantly reduced, while recruitment in the promoter region of Il4 was significantly increased (P<0.01). Conclusions: In both PE patients and mice with PE model, the relative expression level of histone demethyltransferase Jmjd3 is significantly up-regulated, which further induces the demethylation of H3K27me3 in the Ifng promoter region and promotes the initial CD4+ T cells to Th1 cell differentiation and development, leading to an imbalance of Th1/Th2, which may be one of the important reasons for the development of preeclampsia.