Abstract
The p66shc adaptor protein mediates age-associated oxidative stress. We examined the role of p66shc in endothelial nitric oxide synthase (eNOS) signaling. Overexpression of p66shc inhibited eNOS-dependent NO production. RNAi-mediated down-regulation of endogenous p66shc led to activation of the proto-oncogene ras, and Akt kinase, with a corresponding increase in phosphorylation of eNOS at S1177 (S1179 on bovine eNOS). In rat aortic rings, down-regulation of p66shc suppressed the vasoconstrictor response to phenyephrine that was abrogated by treatment with the NOS inhibitor l-NAME, and enhanced vasodilation induced by sub-maximal doses of acetylcholine. These findings highlight a pivotal role for p66shc in inhibiting endothelial NO production, and endothelium-dependent vasorelaxation, that may provide important mechanistic information about endothelial dysfunction seen with aging.
Publication types
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Research Support, N.I.H., Extramural
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Research Support, Non-U.S. Gov't
MeSH terms
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Acetylcholine / pharmacology
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Adaptor Proteins, Signal Transducing / genetics
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Adaptor Proteins, Signal Transducing / metabolism*
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Aging / metabolism*
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Animals
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Aorta / metabolism
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COS Cells
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Chlorocebus aethiops
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Endothelial Cells / cytology
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Endothelial Cells / metabolism
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Endothelium, Vascular / metabolism*
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Enzyme Inhibitors / pharmacology
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Humans
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Male
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NG-Nitroarginine Methyl Ester / pharmacology
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Nitric Oxide / biosynthesis*
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Nitric Oxide Synthase Type III / antagonists & inhibitors
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Nitric Oxide Synthase Type III / metabolism*
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Organ Culture Techniques
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Protein Processing, Post-Translational / drug effects
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Protein Processing, Post-Translational / physiology
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Proto-Oncogene Mas
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Rats
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Rats, Inbred WKY
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Shc Signaling Adaptor Proteins
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Signal Transduction / drug effects
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Signal Transduction / physiology
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Src Homology 2 Domain-Containing, Transforming Protein 1
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Umbilical Veins / cytology
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Umbilical Veins / metabolism
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Vasodilation / physiology*
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Vasodilator Agents / pharmacology
Substances
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Adaptor Proteins, Signal Transducing
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Enzyme Inhibitors
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MAS1 protein, human
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Proto-Oncogene Mas
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SHC1 protein, human
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Shc Signaling Adaptor Proteins
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Shc1 protein, rat
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Src Homology 2 Domain-Containing, Transforming Protein 1
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Vasodilator Agents
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Nitric Oxide
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NOS3 protein, human
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Nitric Oxide Synthase Type III
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Acetylcholine
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NG-Nitroarginine Methyl Ester