ACADVL upregulation is associated with placental ferroptosis in intrahepatic cholestasis of pregnancy.

INTRODUCTION

Intrahepatic cholestasis of pregnancy (ICP) is a disorder characterized by maternal pruritus and elevated total bile acid concentrations during pregnancy, posing severe fetal risks associated with placental dysfunction. However, the mechanisms underlying ICP remain to be fully elucidated.

METHODS

An integrated approach was employed, utilizing placental scRNA-seq, LC-MS/MS-based lipidomics, and public RNA-seq data. The AUCell package, PPI network analysis, Random Forest, Support Vector Machine, and LASSO regression analyses were utilized to explore mitochondrial functions and identify hub mitochondria-related genes (MRGs). KEGG, GSEA, and GSVA were employed to investigate potential biological mechanisms. Key findings were validated by immunohistochemistry, immunofluorescence, and western blotting. Reactive oxygen species (ROS), malondialdehyde (MDA) and transmission electron microscopy were utilized to evaluate oxidative stress levels, lipid peroxidation and conduct ultrastructural examinations of mitochondria, respectively.

RESULTS

MRGs are primarily distributed in villous cytotrophoblast (VCT). KEGG analysis of VCT indicated a close association with oxidative phosphorylation, ROS, Lipid. ACADVL was identified as a hub MRG and was found increased in ICP placenta, particularly in VCT. Functional analysis of ACADVLhigh VCT revealed enrichment in fatty acid metabolism and oxidative phosphorylation. Lipidomics identified substantial alterations in glycerophospholipid and glycerolipid metabolism, and polyunsaturated fatty acid (PUFA) metabolism pathways. Experimentally, we observed the mitochondrial ACADVL localization, increased DRP1, decreased MFN2 and GPX4, and increased ROS and MDA levels in ICP. Electron microscopy revealed ultrastructural features consistent with ferroptosis.

CONCLUSION

This study proposes a novel model linking ACADVL, lipid metabolism, mitochondrial dysfunction, and ferroptosis in ICP pathogenesis.