A novel peptide relieves endothelial cell dysfunction in preeclampsia by regulating the PI3K/mTOR/HIF1α pathway

Preeclampsia (PE) is a pregnancy-specific complication characterized by hypertension and proteinuria, and it is one of the primary global causes of maternal and perinatal mortality. Poor remodeling of placental arteries and endothelial dysfunction serve important roles in the pathogenesis of PE. Peptide derived from complement C4 A chain (PDCC4) was identified in our previous peptidome analysis of serum from patients with PE. The present study aimed to investigate the effect of PDCC4 on endothelial dysfunction in PE. TNF-α stimulated HUVECs were employed to mimic endothelial dysfunction in PE, and Cell Counting Kit 8 assay, wound healing assay, tube formation assay, RNA-sequencing (seq) and western blot analysis were performed using HUVECs. Moreover, an in vivo model of PE was established using pregnant rats treated with lipopolysaccharide (LPS), and blood pressure monitoring, histopathological examination, ELISA and immunohistochemistry were performed on rats. It was found that TNF-α impaired proliferation, migration and tube formation of HUVECs, but pretreatment with PDCC4 moderated these effects. RNA-seq and western blotting demonstrated that the PI3K/mTOR/HIF1α signaling pathway was activated by PDCC4, and a selective PI3K inhibitor reversed the protective function of PDCC4 on TNF-α stimulated HUVECs. Additionally, PDCC4 alleviated hypertension, histopathological changes of placenta and kidney and the expression levels of endothelial injury markers and inflammatory cytokines induced by LPS in rats. These results suggested that PDCC4 relieved endothelial dysfunction in PE via PI3K/mTOR/HIF1α signaling pathway and may be a potential therapy for PE.