The goals of the proposal research project are: 1) to prepare and train the candidate for a career in cardiovascular research providing him with the necessary education, environment, and support, and 2) to gain further insight into the role of heat shock proteins (Hsp) in modulating the response of vascular smooth muscle cells (VSMC) to oxidative stress. The candidate will be provided with extensive education in biochemistry, physiology, pharmacology, pathology, signal transduction, research methods, statistics, and epidemiology as it pertains to the cardiovascular system. The candidate will be supported and mentored by this sponsor, Bradford C. Berk who with the research advisory committee will monitor the candidate's progress. Finally, the Department of Medicine and the Division of Cardiology at the University of Washington will provide full commitment and support to developing the candidate's career into an independent investigator. The below proposed project is the first attempt at attaining these goals. Hsps are a family of cellular proteins that are proposed to maintain cell survival. Initially, Hsps were demonstrated to play an important role in protein folding and chaperoning. Recent evidence, however, indicates that Hsps also function to mediate signal transduction and to prevent apoptosis. Hsps are induced by sublethal cellular stress such as hypoxia, ionizing radiation, toxins, cytokines, and reactive oxygen (ROS) such as H2O2, O2-, and OH. ROS are normal products of respiration and metabolism of fatty acids in the presence of O2. However, the generation of excessive quantities of ROS or the failure to scavenge ROS leads to oxidative stress. Risk factors for atherosclerosis such as hyperlipidemia, diabetes mellitus, cigarette smoking, hypertension, and hyperhomocysteinemia cause oxidative stress and have been demonstrated to change vessel redox state. The investigators have previously demonstrated that ROS stimulate cultured VSMC proliferation and active intracellular kinase associated with cell growth such as mitogen-activated protein kinases (MAPK). Furthermore, they have demonstrated the novel finding that oxidative stress-stimulated VSMC synthesize and secrete proteins into the extracellular media which in turn activate MAPK in an autocrine and paracrine fashion. Additional characterization of these oxidative stress-synthesized and -secreted proteins resulted in identification of members of the heat shock protein (Hsp) 90 family. In response to oxidative stress, VSMC specifically increase de novo production of intracellular Hsp90 B and stimulate extracellular secretion of pre-formed Hsp90 a. To further characterize the oxidative stress-mediated induction and secretion of Hsp90 in VSMC, they propose the following three specific aims: 1) Determine the role of Hsp90 as mediator of VSMC cytoprotection and anti-apoptosis in response to ROS. 2) Determine the role of heat shock factor (HSF-1) protein phosphorylation by specific MAPK family members in regulation of ROS-stimulated Hsp90 B synthesis in VSMC. 3) Determine the cellular mechanisms responsible for oxidative stress-mediated Hsp90 alpha secretion in VSMC. Elucidating the regulation of the Hsp90 by ROS will provide insights into pathways by which VSMC respond to vessel oxidation-a key process in atherogenesis.
| Kim, Francis; Tysseling, Kelly A; Rice, Julie et al. (2005) Free fatty acid impairment of nitric oxide production in endothelial cells is mediated by IKKbeta. Arterioscler Thromb Vasc Biol 25:989-94 |
