Hypoxic development down-regulates endothelial Piezo1 via HIF1-α signaling and impairs Piezo1-mediated vasorelaxation.

Hypoxia plays a critical role in regulating vascular function, with endothelial mechanosensitive proteins, such as the piezo-type mechanosensitive ion channel component 1 (Piezo1), emerging as key players in maintaining vascular homeostasis. Piezo1 is essential for nitric oxide-mediated vasodilation and vascular tone regulation. However, the impact of hypoxia on endothelial Piezo1 expression and function remains poorly understood. The present study investigated the regulation of Piezo1 and mechanosensitive-related genes (MRGs) during hypoxic development and their role in fetal growth restriction (FGR). Using publicly available datasets, we identified distinct transcriptional profiles in placental endothelial cells from human FGR pregnancies and human umbilical vein endothelial cells (HUVEC) exposed to hypoxia. Functional enrichment analysis revealed significant changes in pathways related to PI3K-Akt, MAPK, and VEGF signaling and responses to mechanical stimuli. Hypoxia-related transcription factors, particularly HIF-1α and HIF-1β, were enriched in the promoter regions of differentially expressed MRGs, including Piezo1, suggesting a conserved regulatory mechanism. In vitro experiments confirmed hypoxia-induced down-regulation of Piezo1 in HUVEC, while ex vivo studies using a chicken embryo model demonstrated impaired Piezo1-mediated vasodilation following hypoxic development. Combined, these findings highlight the critical role of hypoxia in modulating endothelial Piezo1 expression and function, providing mechanistic insights into vascular dysfunction associated with FGR. The present study provides evidence for the potential to target Piezo1 and HIF-1α signaling as therapeutic strategies to improve vascular outcomes in offspring of pregnancies complicated by hypoxia and FGR.