Interspecific correlation between red blood cell mitochondrial ROS production, cardiolipin content and longevity in birds
Résumé
Mitochondrial respiration releases reactive
oxygen species (ROS) as by-products that can damage
the soma and may in turn accelerate ageing. Hence,
according to “the oxidative stress theory of ageing”,
longer-lived organisms may have evolved mechanisms
that improve mitochondrial function, reduce ROS production
and/or increase cell resistance to oxidative damage.
Cardiolipin, an important mitochondrial innermembrane
phospholipid, has these properties by binding
and stabilizing mitochondrial inner-membrane proteins.
Here, we investigated whether ROS production,
cardiolipin content and cell membrane resistance to
oxidative attack in freshly collected red blood cells
(RBCs) are associated with longevity (range 5–35 years)
in 21 bird species belonging to seven Orders. After
controlling for phylogeny, body size and oxygen consumption,
variation in maximum longevity was significantly
explained by mitochondrial ROS production and
cardiolipin content, but not by membrane resistance to
oxidative attack. RBCs of longer-lived species produced
less ROS and contained more cardiolipin than RBCs of
shorter-lived species did. These results support the oxidative
stress theory of ageing and shed light on mitochondrial
cardiolipin as an important factor linking ROS
production to longevity