CCN1-induced senescence and dysfunction of umbilical cord blood endothelial colony-forming cells in the pathogenesis of preeclampsia.

Introduction: Maternal vascular dysfunction and impaired placental angiogenesis are key features of preeclampsia (PE). Umbilical cord blood-derived endothelial colony-forming cells (CB-ECFCs) contribute to fetal endothelial repair and vascular network formation, but their phenotype in PE remains incompletely understood. Methods: We investigated whether the matricellular protein CCN1 is associated with CB-ECFC senescence and dysfunction. CB-ECFCs were isolated from pregnancies complicated by PE (n = 8) and healthy pregnancies (n = 9). Cellular senescence was assessed by SA-β-galactosidase staining, qPCR, and Western blotting of senescence-associated markers and senescence-associated secretory phenotype factors. Control-derived CB-ECFCs were exposed to recombinant CCN1, with or without the gamma-secretase inhibitor DAPT, and senescence-associated proteins, cleaved Notch1, the redox-responsive protein HO-1, the inflammatory factor TNF-α, and the DNA damage-response marker gamma-H2AX were examined. Results: PE-derived CB-ECFCs showed reduced colony yield, increased senescence-associated markers, and higher secreted and cell-associated CCN1 expression. Recombinant CCN1 increased senescence-associated markers, cleaved Notch1, HO-1, TNF-α, and γ-H2AX and impaired CB-ECFC metabolic activity, migration, and tube formation. DAPT attenuated selected molecular changes and partially restored tube formation but not wound closure. Discussion: These findings identify increased CCN1 as a feature of PE-derived CB-ECFCs and support an association between CCN1 exposure, Notch1 signaling, oxidative stress, and CB-ECFC senescence and dysfunction. The CCN1/Notch1 axis may represent a potential mechanism contributing to fetoplacental endothelial dysfunction in PE.