We have continued to explore the role that reactive oxygen species (ROS)play in signal transduction pathways. We have shown that a variety of growth factors and cytokines induce the generation of ROS following ligand binding. Our studies suggest that the pathway leading to ROS generation involves the activation of the small GTP-binding proteins ras and rac1. This has led us to explore fully the role of these proteins, and in particular, their role in vascular biology. We have also explored the role that ROS play in apoptosis, and more recently in replicative senescence. Our current focus is on how small the cellular redox state regulates biological events. In the last year we have been able to demonstrate that mitochondrial oxidants stimulate a signaling pathway that regulates glycogen synthase kinase 3. We have proposed that mitochondrial oxidants may function physiologically to regulate cellular metabolism. In this scenario the release of mitochondrial oxidants stimulated by an increase in metabolism would activate the above pathway , that in turn , would feedback and inhibit metabolism, and hence oxidant generation. In addition, we have attempted to explore the relationship between senescence and cardiovascular disease. We were able to show that the small GTPase ras can induce senescence in primary human fibroblasts through an increase in mitochondrial oxidants. These results help stimulate a growing interest in the regulation of mitochondrial oxidant production. We were also able to show that homocysteine, a known cardiac risk factor, can accelerate the rate of endothelial senescence. Interestingly, preliminary evidence suggests that senescent cells colocalize with atherosclerotic plaque in human arterial segments in vivo. Finally, we have attempted to identify direct targets of oxidant stress. We have developed a new assay to allow for the rapid isolation and subsequent identification by mass spectroscopy of proteins in which glutathione has been added in a covalent fashion. We are attempting to understand the physiological relevance of glutathiolation in various signaling pathways. - reactive oxygen species (ROS), GTP-binding proteins, apoptosis

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Intramural Research (Z01)
Project #
1Z01HL005012-03
Application #
6290454
Study Section
Cell Biology Integrated Review Group (CB)
Project Start
Project End
Budget Start
Budget End
Support Year
3
Fiscal Year
1999
Total Cost
Indirect Cost
Name
National Heart, Lung, and Blood Institute
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Finkel, Toren (2012) Relief with rapamycin: mTOR inhibition protects against radiation-induced mucositis. Cell Stem Cell 11:287-8
Finkel, Toren; Quyyumi, Arshed A (2011) Genetic links between circulating cells and cardiovascular risk. Circ Cardiovasc Genet 4:218-20
Lee, In Hye; Finkel, Toren (2009) Regulation of autophagy by the p300 acetyltransferase. J Biol Chem 284:6322-8
Finkel, Toren; Hwang, Paul M (2009) The Krebs cycle meets the cell cycle: mitochondria and the G1-S transition. Proc Natl Acad Sci U S A 106:11825-6
Liu, Hongjun; Fergusson, Maria M; Castilho, Rogerio M et al. (2007) Augmented Wnt signaling in a mammalian model of accelerated aging. Science 317:803-6
Schieke, Stefan M; Finkel, Toren (2007) TOR and aging: less is more. Cell Metab 5:233-5
Song, Shiwei; Finkel, Toren (2007) GAPDH and the search for alternative energy. Nat Cell Biol 9:869-70
Finkel, Toren; Serrano, Manuel; Blasco, Maria A (2007) The common biology of cancer and ageing. Nature 448:767-74
Cheung, Kevin J; Tzameli, Iphigenia; Pissios, Pavlos et al. (2007) Xanthine oxidoreductase is a regulator of adipogenesis and PPARgamma activity. Cell Metab 5:115-28
Khakoo, Aarif Y; Pati, Shibani; Anderson, Stasia A et al. (2006) Human mesenchymal stem cells exert potent antitumorigenic effects in a model of Kaposi's sarcoma. J Exp Med 203:1235-47

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