Fig. 2.

Heterogeneity in susceptibility of ECs to aging-associated stressors and responses. a ECs in numerous tissues (e.g., liver, heart, muscle, lung) are more prone to undergoing apoptosis, induced by various stressors (e.g., therapy-induced toxicity, aging), in comparison to other cell types. b ECs in several aging mouse tissues (e.g., heart, kidney, liver) have been shown to be more prone to acquiring a senescent gene expression signature in comparison to other cell types, as illustrated by a more prominent senescence-associated (secretory) phenotype in ECs. c Heterogeneous EC turnover rates during lifespan: the majority of ECs in the brain neurovascular unit of mice do not exhibit signs of turnover throughout lifespan, whereas a proportion of cardiac ECs (human) have been predicted to renew annually, without signs of decline with advancing age. In mice, hepatic ECs lining the portal and central vein were shown to not divide or turnover, while sinusoidal ECs show signs of active division/turnover during the animals’ lifespan. EC = endothelial cell; SMC = smooth muscle cell