Endothelial extracellular vesicles preserve vascular smooth muscle cell identity but do not reverse endothelial senescence.

Vascular aging is characterized by endothelial senescence and vascular smooth muscle cell (VSMC) phenotypic switching, yet the role of endothelial extracellular vesicles (EVs) in these processes remains unclear. We show that EVs from non-senescent endothelial cells prevent PDGF-BB-induced VSMC dedifferentiation, preserving contractile markers and limiting migration. In endothelial cells, EVs protected against TNF-α-induced eNOS downregulation but failed to reverse inflammatory and mitochondrial features of senescence after short-term exposure, highlighting a context-dependent protective role.