From Nature, information on yet another part of age-related degeneration that can be blamed on accumulated damage to mitochondria. "As the cells in blood-vessel walls grow old, their energy-generating machinery begins to leak, says the team. This releases reactive molecules into the vessels, triggering a chain of reactions that ultimately clogs up arteries and increases the risk of having a heart attack ... They speculate that an increased flow of reactive oxygen damages the blood vessel's walls. The body then mounts an immune response to repair this damage, and scientists have already established that cells trying to fix arterial damage can create problems." Fixing mitochrondial damage is one of the proposed Strategies for Engineered Negligible Senescence.
Link: http://www.nature.com/news/2005/050523/full/050523-7.html