Altra ricerca che demolisce la teoria dell'invecchiamento da stress ossidativo mitocondriale. Con buona pace dei sostenitori (A. De Grey per esempio?) e dei divoratori/propinatori nostrani di antiossidanti in tutte le salse
http://opac.yale.edu/news/article.aspx?id=8625
New Haven, Conn. — In a new study, Yale University researchers have
identified a pathway by which reactive oxygen species (ROS) molecules,
which are usually implicated in the aging process due to their damage
to DNA, can also act as cellular signaling molecules that extend
lifespan. The study, which provides insights into the underlying
mechanisms of the ROS signaling process, is published in the June
issue of Cell Metabolism.
Increased ROS, and their effects at the cellular level, can lead to
oxidative stress, which is involved in many diseases and aging. But
ROS are also necessary for the proper functioning of the immune system
and other biological functions. Using the model organism yeast, the
Yale team set out to determine whether regulating ROS and their
ability to act as signaling molecules could impact the aging process.
Inhibiting a signaling pathway called Target of Rapamycin (TOR), which
is involved in sensing nutrients and cell growth, increases lifespan
in yeast, as it does in mice. The Yale team found that a key way this
occurs is by altering the function of cellular powerhouses called
mitochondria so that they produce more signaling ROS.
The concept that ROS are important cellular signaling molecules, and
not just agents of damage and stress, has grown to be widely
accepted, said lead author Gerald S. Shadel, Ph.D., professor of
pathology and genetics at Yale School of Medicine. Remarkably, in
this study, we show that their purposeful production by mitochondria
can even provide an adaptive signal that can delay aging.
Since the TOR pathway operates largely the same in yeast as it does in
humans, the new connections to mitochondrial ROS signaling and aging
in this study may be more widely applicable. Shadel said that new ways
to intervene in age-related pathology may stem from these basic
studies. Trials targeting the TOR pathway as an anti-cancer strategy
in humans are already underway. Our study suggests that carefully
augmenting mitochondria and ROS production in humans may also be
beneficial in combating aging and associated diseases.
Other authors are Yong Pan and Elizabeth A. Schroeder of Yale School
of Medicine; Alejandro Ocampo of the Yale Department of Biochemistry
and Molecular Biology; and Antonio Barrientos of Yale and the
University of Miami Miller School of Medicine.
This study was supported by grants from the National Institutes of
Health and the Florida Department of Health/James and Esther King
Biomedical Research Program.