Microparticles Induce Cell Cycle Arrest Through Redox‐Sensitive Processes in Endothelial Cells: Implications in Vascular Senescence

Background Chronic disease accelerates endothelial dysfunction in aging, a process associated with cell senescence. However, the mechanisms underlying this process are unclear. We examined whether endothelial cell (EC)‒derived microparticles (MPs) facilitate EC senescence and questioned the role of reactive oxygen species in this process. Methods and Results Senescence was induced by sequential passaging of primary mouse ECs. Cells retained phenotypic characteristics of ECs from passage 4 through passage 21. Passage 21 ECs exhibited features of senescence, including increased staining of senescence‐associated β‐galactosidase (SA‐βgal), a greater percentage of cells in G1/G0 phase of the cell cycle, and increased phosphorylation of p66Shc (P