Figure 1. Model implicating the intracellular and extracellular molecular mechanisms involved in vascular aging. The inter-relationships between the processes remain unclear and are depicted by arrows highlighting possible links. (1) Reactive oxygen species (ROS) can damage the mitochondria and mitochondrial DNA, which can further exacerbate mitochondrial dysfunction, and (2) can also damage the nuclear genome (yellow stars); (3) Inter-communication is evident between the mitochondrial and nuclear genomes but remains complex. Epigenetic modifications are also involved in altering the nuclear DNA (green circles), and the chromosomal telomeres become shortened. Protein homeostasis is disrupted, and overall cellular resilience to molecular stressors (red arrows) is impaired. ROS, reactive oxygen species.