Assembly of Cytoplasmic Stress Granules in Placentas in Women with Preeclampsia

Inflammation is a well-recognized factor associated with preeclampsia (PE). Stress granules (SGs) have been shown to play an important role in regulating inflammation and immune responses. However, whether SGs are involved in the pathogenesis of PE has not been studied. Here, we evaluated the expression of SG components in placenta of pregnancies with PE. Placental samples or serum were collected from PE patients ( n = 31) or healthy age-matched pregnancy ( n = 17). mRNA expressions of SG-associated genes in placenta from PE or normal pregnancies were detected by real-time quantitative PCR, and protein expressions of HuR and G3BP were detected using western blot. Immunofluorescence staining was performed to evaluate SG components expression in placentas or 10% serum treated HTR-8/Svneo cells using antibodies against HuR and G3BP. Our study showed higher levels of elavl1 , lsm2 , lsm4 , and ago1 mRNA expression and SG marker proteins expression in placental homogenates of PE patients. HuR/G3BP-positive SG structure was further observed in placental villi of PE by immunofluorescence assay. Besides, serum from PE patients could induce SG aggregation in human trophoblast cell line HTR-8/Svneo cells, suggesting the involvement of SGs in the development of PE.