Constitutive Activation of <i>rac</i> 1 Results in Mitochondrial Oxidative Stress and Induces Premature Endothelial Cell Senescence

These findings paint a picture in which the constitutive activation of rac1, via the generation of ceramide, results in mitochondrial oxidative stress and premature endothelial cell senescence. However, they speak against a role for endogenous rac1 activation in the induction of mitochondrial oxidative stress associated with replicative senescence of endothelial cells.