Deletion of p66shc gene protects against age-related endothelial dysfunction.
BACKGROUND
Enhanced production of reactive oxygen species (ROS) has been recognized as the major determinant of age-related endothelial dysfunction. The p66shc protein controls cellular responses to oxidative stress. Mice lacking p66shc (p66shc-/-) have increased resistance to ROS and a 30% prolonged life span. The present study investigates age-dependent changes of endothelial function in this model.


RESULTS
Aortic rings from young and old p66shc-/- or wild-type (WT) mice were suspended for isometric tension recording. Nitric oxide (NO) release was measured by a porphyrinic microsensor. Expression of endothelial NO synthase (eNOS), inducible NOS (iNOS), superoxide dismutase, and nitrotyrosine-containing proteins was assessed by Western blotting. Nitrotyrosine residues were also identified by immunohistochemistry. Superoxide (O2-) production was determined by coelenterazine-enhanced chemiluminescence. Endothelium-dependent relaxation in response to acetylcholine was age-dependently impaired in WT mice but not in p66shc-/- mice. Accordingly, an age-related decline of NO release was found in WT but not in p66shc-/- mice. The expression of eNOS and manganese superoxide dismutase was not affected by aging either in WT or in p66shc-/- mice, whereas iNOS was upregulated only in old WT mice. It is interesting that old WT mice displayed a significant increase of O2- production as well as of nitrotyrosine expression compared with young animals. Such age-dependent changes were not found in p66shc-/- mice.


CONCLUSIONS
We report that inactivation of the p66shc gene protects against age-dependent, ROS-mediated endothelial dysfunction. These findings suggest that the p66shc is part of a signal transduction pathway also relevant to endothelial integrity and may represent a novel target to prevent vascular aging.
Francia
Pietro
P
Cardiovascular Research & Cardiology, Institute of Physiology, Zürich, Irchel and University Hospital, Zürich, Switzerland.
delli Gatti
Chiara
C
Bachschmid
Markus
M
Martin-Padura
Ines
I
Savoia
Carmine
C
Migliaccio
Enrica
E
Pelicci
Pier Giuseppe
PG
Schiavoni
Marzia
M
Lüscher
Thomas Felix
TF
Volpe
Massimo
M
Cosentino
Francesco
F
D048868:Adaptor Proteins, Signal Transducing / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D000375:Aging / Q000502:physiology*; D000818:Animals; D001011:Aorta; D004730:Endothelium, Vascular / Q000378:metabolism / Q000503:physiopathology*; D007537:Isometric Contraction; D008136:Longevity / Q000235:genetics; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009569:Nitric Oxide / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; D018384:Oxidative Stress; D011506:Proteins / Q000737:chemistry; D017382:Reactive Oxygen Species; D055765:Shc Signaling Adaptor Proteins; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D013482:Superoxide Dismutase / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives / Q000032:analysis; D014661:Vasoconstriction
D048868:Adaptor Proteins, Signal Transducing; D011506:Proteins; D017382:Reactive Oxygen Species; D055765:Shc Signaling Adaptor Proteins; C528034:Shc1 protein, mouse; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D009569:Nitric Oxide; C002744:3-nitrotyrosine; D014443:Tyrosine; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496317:Nos2 protein, mouse; C496315:Nos3 protein, mouse; D013482:Superoxide Dismutase