STAT3-mediated effects of methyltransferase inhibitor 5-aza-2'-deoxycytidine on preeclampsia

To investigate the effects of 5-aza-2'-deoxycytidine (5-AZA-DC) on preeclampsia (PE) and functional mechanisms dependent on STAT3.

Trophoblastic cells (HTR8/Svneo, JEG-3, JAR and BeWo) were used to constructed STAT3-overexpressing or -silenced cells. qRT-PCR, Western blot, and FISH were used to detect mRNA and protein expression. GST-pull down, ChIP and dual luciferase reporter were used to prove the association of STAT3 and PTEN or TSC2, LC-MS/MS for proteome, and MeDIP-Seq for transcriptome. CCK-8 and flow cytometry were used to examine cell proliferation and apoptosis. C57BL/6J mice were divided into 4 groups (control, control + 5-AZA-DC, PE and PE + 5-AZA-DC). Systolic blood pressure, 24-h urinary protein, APTT, D-D, PT, ALT, Scr, and BUN were determined. Placental blood flow velocity was detected by Doppler ultrasound, HE staining for kidney injury.

STAT3, PTEN and TSC2 were the dominantly differential expressed genes in preeclampsia. Aberrant STAT3 expression increased DNMT1 levels. STAT3 regulated PTEN promoter activity. STAT3 interacted with PTEN and TSC2. DNMT1 was increased while STAT3, PTEN and TSC2 were decreased by 5-AZA-DC. Cell proliferation was promoted and apoptosis was inhibited by 5-AZA-DC. PE-induced STAT3 down-regulation was restored by 5-AZA-DC. Systolic blood pressure, 24-h urinary protein, APTT, D-D, PT, ALT, Scr and BUN were increased, and velocity of placental blood flow was inhibited in PE compared with control mice, while 5-AZA-DC relived these indicators.

Preeclampsia symptoms was relieved by 5-AZA-DC, suggesting that 5-AZA-DC could be used as a potential drug for epigenetic treatment of preeclampsia.