Puerarin alleviates symptoms of preeclampsia through the repression of trophoblast ferroptosis via the CREB/HO-1 pathway

Introduction

Preeclampsia (PE) is a pregnancy-associated complication characterised by new-onset hypertension and proteinuria. This study explored the therapeutic potential of puerarin (Pue) in PE and investigated the underlying mechanism, with a focus on placental ferroptosis.

Methods

Using an N^G-nitro-L-arginine methyl ester (L-NAME)-induced PE mouse model, we assessed the effects of Pue on PE phenotypes and placental ferroptosis. Antioxidative and anti-ferroptotic effects of Pue were studied in three ferroptotic cell models (hypoxia/reperfusion, cobalt chloride, and erastin). The regulation of Pue on cAMP response element binding protein (CREB) and heme oxygenase-1 (HO-1) was evaluated through gain- and loss-of-function assays. Luciferase assays were used to elucidate the effect of Flag-CREB on Hmox1 promoter fragments. CREB/HO-1 modulation by Pue was validated in mouse placentas with PE.

Results

Pue significantly alleviated maternal hypertension, proteinuria, fetal growth restriction, and placental damage in PE mice. This was associated with an upregulation of the anti-ferroptosis system (glutathione peroxidase 4 [GPX4], cys2/glutamate antiporter [SLC7A11], and glutathione [GSH]) and repression of reactive oxygen species (ROS) and malondialdehyde (MDA) in trophoblasts. Pue reduced HO-1 and CREB, and HO-1 deficiency upregulated GPX4 and SLC7A11. Manipulation of CREB expression led to changes in HO-1/GPX4; whereas, the regulation reversed by Pue administration. Flag-CREB enhanced luciferase activity on the full length Hmox1 promoter (−2000/+78), which contains three CREB1 binding sites (S1–S3). In contrast, no increase in luciferase activity was observed with promoter fragments (−850/+78) and (−550/+78), which contain only the CREB1 binding sites S2 and S3, respectively.

Discussion

Pue ameliorated PE-like symptoms in mice by repressing trophoblast ferroptosis via inhibition of CREB signalling and affecting the Homx1 promoter.