The study investigates the role of telomere function in endothelial cell senescence and its impact on atherosclerosis. The researchers examined senescence-associated β-galactosidase (β-gal) activity in coronary and internal mammary arteries from individuals with ischemic heart diseases. Strong β-gal staining was observed in atherosclerotic lesions of coronary arteries but not in internal mammary arteries, indicating the presence of senescent vascular endothelial cells. To further explore the effects of telomere dysfunction, the team induced senescence in human aortic endothelial cells (HAECs) by inhibiting telomere function. Senescent HAECs exhibited increased ICAM-1 expression and decreased eNOS activity, both of which are implicated in atherogenesis. Conversely, introducing telomerase catalytic component (TERT) significantly extended the lifespan of HAECs and inhibited the functional alterations associated with senescence. The findings suggest that endothelial cell senescence, induced by telomere shortening, may contribute to atherogenesis, highlighting the importance of telomere function in vascular health.The study investigates the role of telomere function in endothelial cell senescence and its impact on atherosclerosis. The researchers examined senescence-associated β-galactosidase (β-gal) activity in coronary and internal mammary arteries from individuals with ischemic heart diseases. Strong β-gal staining was observed in atherosclerotic lesions of coronary arteries but not in internal mammary arteries, indicating the presence of senescent vascular endothelial cells. To further explore the effects of telomere dysfunction, the team induced senescence in human aortic endothelial cells (HAECs) by inhibiting telomere function. Senescent HAECs exhibited increased ICAM-1 expression and decreased eNOS activity, both of which are implicated in atherogenesis. Conversely, introducing telomerase catalytic component (TERT) significantly extended the lifespan of HAECs and inhibited the functional alterations associated with senescence. The findings suggest that endothelial cell senescence, induced by telomere shortening, may contribute to atherogenesis, highlighting the importance of telomere function in vascular health.