This proposal describes a five-year plan for the attainment of research skills necessary in the career development of an academic physician-scientist in Critical Care. The candidate is a junior faculty member in an established Division of Pediatric Critical Care and has preliminary research training in pulmonary physiology. The award will be utilized to broaden this background by acquiring a foundation in vascular cell biology and the biochemistry of nitrosative signaling to enable independent investigation of erythrocytic and endothelial communication in the pathobiology of disrupted vasomotor control. Ben Gaston, MD, a leader in pulmonary nitrosothiol signaling research, will serve as primary mentor for the award and Brian Duling, PhD, a pioneer in microcirculation research and vascular cell biology will serve as Co-Mentor. Specific expertise in nitrosative hemoglobin chemistry will be provided by collaboration with investigators from Duke and the University of Pennsylvania. Additionally, an advisory committee of senior scientists will provide scientific and career guidance. Research conducted with this award will investigate the role of the erythrocyte as a link between dysregulated pulmonary blood flow and remote inflammation via nitric oxide (NO) and hemoglobin (Hb) interactions. There is evidence for a nitrosative signaling network in which Hb and NO reactions are balanced to transduce regional redox gradients, coupling oxygen tension and the distribution of NO (and thus flow), in vascular beds. In this regard, we hypothesize oxidative stress in the systemic inflammatory response syndrome (SIRS) may disrupt normal erythrocytic nitrosative signaling and explain dysregulated pulmonary blood flow in this state.
We aim, in this project, to determine (1) the degree of abnormal NO loading of RBCs in SIRS, correlating with onset and severity of respiratory failure and (2) to determine the change in Hb vasoactivity in the lung following addition of NO to a beta-chain cysteine (betacys93), the allosteric control of this change, and (3) the endothelial regulation of Hb-based nitrosative signaling. We will pursue these goals on three levels: (1) molecular investigation of intraerythrocytic Hb approximately NO chemistry (2) pharmacologic, immunohistochemical, and proteomic investigations of NO signaling between erythrocytes and endothelial cells in culture, and (3) physiologic correlation of our findings in the isolated murine lung, permitting further transgenic and pharmacologic query. At the conclusion of this project, we expect to define the mechanism of NO traffic between remote vascular beds and the lung via the erythrocyte, as effected by serial transnitrosation reactions. At the conclusion of the development period, the candidate will have acquired skills to pursue further independent investigation of (S)NO and erythrocyte vasoactivity with the hope of informing therapy directed at the dysregulation of regional blood flow in the lung. The candidate's long-term goal is to define the mechanism of NO traffic between regional vascular beds via the erythrocyte, and its role in the evolution of multiple organ failure in severe inflammatory states.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Clinical Investigator Award (CIA) (K08)
Project #
5K08GM069977-02
Application #
6839438
Study Section
Respiratory Physiology Study Section (RESP)
Program Officer
Somers, Scott D
Project Start
2004-01-01
Project End
2008-12-31
Budget Start
2005-01-01
Budget End
2005-12-31
Support Year
2
Fiscal Year
2005
Total Cost
$121,432
Indirect Cost
Name
University of Virginia
Department
Pediatrics
Type
Schools of Medicine
DUNS #
065391526
City
Charlottesville
State
VA
Country
United States
Zip Code
22904
Doctor, Allan (2014) How to guide transfusion decision-making? That is the question. Pediatr Crit Care Med 15:895-6
Rogers, Stephen C; Gibbons, Lindsey B; Griffin, Sherraine et al. (2013) Analysis of S-nitrosothiols via copper cysteine (2C) and copper cysteine-carbon monoxide (3C) methods. Methods 62:123-9
Rogers, Stephen C; Said, Ahmed; Corcuera, Daniella et al. (2009) Hypoxia limits antioxidant capacity in red blood cells by altering glycolytic pathway dominance. FASEB J 23:3159-70
Marozkina, Nadzeya; Gaston, Benjamin; Doctor, Allan (2008) Transnitrosation signals oxyhemoglobin desaturation. Circ Res 103:441-3
Butler, Paris D; Ly, Daphne P; Longaker, Michael T et al. (2008) Use of organotypic coculture to study keloid biology. Am J Surg 195:144-8
Palmer, Lisa A; Doctor, Allan; Chhabra, Preeti et al. (2007) S-nitrosothiols signal hypoxia-mimetic vascular pathology. J Clin Invest 117:2592-601
Xia, Wei; Longaker, Michael T; Yang, George P (2006) P38 MAP kinase mediates transforming growth factor-beta2 transcription in human keloid fibroblasts. Am J Physiol Regul Integr Comp Physiol 290:R501-8
Bin, Jian-Ping; Doctor, Allan; Lindner, Jonathan et al. (2006) Effects of nitroglycerin on erythrocyte rheology and oxygen unloading: novel role of S-nitrosohemoglobin in relieving myocardial ischemia. Circulation 113:2502-8
McMahon, Timothy J; Doctor, Allan (2006) Extrapulmonary effects of inhaled nitric oxide: role of reversible S-nitrosylation of erythrocytic hemoglobin. Proc Am Thorac Soc 3:153-60
Gaston, Benjamin; Singel, David; Doctor, Allan et al. (2006) S-nitrosothiol signaling in respiratory biology. Am J Respir Crit Care Med 173:1186-93

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