This looks to me to be hugely important:

Nature 435, 502-506 (26 May 2005) | doi: 10.1038/nature03527

Vascular respiratory uncoupling increases blood pressure and
atherosclerosis
Carlos Bernal-Mizrachi1,4, Allison C. Gates1,4, Sherry Weng1,
Takuji Imamura2, Russell H. Knutsen3, Pascual DeSantis1, Trey
Coleman1, R. Reid Townsend1, Louis J. Muglia2 and Clay F.
Semenkovich1,3

The observations that atherosclerosis often occurs in non-smokers
without elevated levels of low-density lipoprotein cholesterol,
and that most atherosclerosis loci so far identified in mice do
not affect systemic risk factors associated with atherosclerosis1,
suggest that as-yet-unidentified mechanisms must contribute to
vascular disease. Arterial walls undergo regional disturbances of
metabolism2 that include the uncoupling of respiration and
oxidative phosphorylation, a process that occurs to some extent in
all cells and may be characteristic of blood vessels being
predisposed to the development of atherosclerosis3. To test the
hypothesis that inefficient metabolism in blood vessels promotes
vascular disease, we generated mice with doxycycline-inducible
expression of uncoupling protein-1 (UCP1) in the artery wall. Here
we show that UCP1 expression in aortic smooth muscle cells causes
hypertension and increases dietary atherosclerosis without
affecting cholesterol levels. UCP1 expression also increases
superoxide production and decreases the availability of nitric
oxide, evidence of oxidative stress. These results provide proof
of principle that inefficient metabolism in blood vessels can
cause vascular disease.

Abstract at
http://www.nature.com/nature/journal/v435/n7041/abs/nature03527.html

Also, see nature.com article at
http://www.nature.com/news/2005/050523/full/050523-7.html
(registration may be required)

Excerpt from article:
"The researchers think that the leaky mitochondria in ageing
blood-vessel cells could trigger a fatal accumulation of the
plaques that block arteries in atherosclerosis.

"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.
These immune cells attract a form of cholesterol that sticks to
arterial walls, forming plaques."

--
Jim Chinnis   Warrenton, Virginia, USA