Pulmonary endothelial injury typifies the adult respiratory distress syndrome (ARDS). Gram negative bacterial sepsis is the most frequent clinical setting in which ARDS occurs, presumably a result of endotoxin- induced lung injury. In this renewal application, we propose to extend our observations of effects of endotoxin on lung endothelial cells in culture to a molecular level. We propose to test the hypothesis that endotoxin exposure results in increased oxidant stress within endothelial cells which causes increased production of interleukin-1 (IL-1) resulting in increased production of the antioxidant enzyme, manganous superoxide dismutase (MnSOD) (we have demonstrated that the first and last step in this sequence occur). Further, we propose that endotoxin stimulation of prostanoid production by endothelial cells is also oxidant mediated and that prostaglandin E2 (PGE2), a major product of microvascular endothelial cells, modulates IL-1 and thus MnSOD induction. We propose that differences in response of endothelial cells from different organs and from different sites within the lung can be explained by differences in constitutive production of MnSOD and PGE2 and that genetic engineering of endothelial cells to produce increased amounts of MnSOD will render the cells resistant to endotoxin-induced injury. To test these hypotheses we will conduct studies in cultured endothelial cells from large and small vessels in the lungs and from human umbilical veins. We will 1) elucidate the time course of induction of alteration in IL-1 and MnSOD gene expression following exposure of the cells to endotoxin and determine whether the responses are inhibited by antioxidants which access the cell interior, 2) determine whether the endotoxin effect are mimicked by the cytokine TNFalpha (which, like endotoxin, stimulates IL-1 production by endothelial cells) or exogenous IL-1, 3) determine effects of exogenous PGE2 on IL-1 and MnSOD gene expression, 4) compare these responses to endotoxin exposure in cells from different species, organs and sites, 5) determine whether endothelial cells genetically engineered to produce increased amounts of MnSOD are resistant to endotoxin effect and 6) initiate studies of the molecular mechanisms of endotoxin induction of MnSOD gene expression in endothelial cells. These studies follow logically the work supported by this grant over the past five years and promise a new level of understanding of how endotoxin affects endothelial cells and how the deleterious effects of endotoxin can be prevented. Such information will contribute to the development of novel interventions which may find eventual application in the clinical setting.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
2R01HL034208-06
Application #
3346940
Study Section
Respiratory and Applied Physiology Study Section (RAP)
Project Start
1985-05-01
Project End
1995-04-30
Budget Start
1990-05-01
Budget End
1991-04-30
Support Year
6
Fiscal Year
1990
Total Cost
Indirect Cost
Name
Vanderbilt University Medical Center
Department
Type
Schools of Medicine
DUNS #
004413456
City
Nashville
State
TN
Country
United States
Zip Code
37212
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Morris, P E; Wheeler, A P; Meyrick, B O et al. (1995) Escherichia coli endotoxin-mediated endothelial injury is modulated by glutathione ethyl ester. J Infect Dis 172:1119-22
Morello, J P; Plamondon, J; Meyrick, B et al. (1995) Transforming growth factor-beta receptor expression on endothelial cells: heterogeneity of type III receptor expression. J Cell Physiol 165:201-11
Meyrick, B; Berry Jr, L C; Christman, B W (1995) Response of cultured human pulmonary artery endothelial cells to endotoxin. Am J Physiol 268:L239-44
Brigham, K L; Canonico, A E; Meyrick, B O et al. (1994) Gene therapy for inflammatory diseases. Prog Clin Biol Res 388:361-5
Meyrick, B; Magnuson, M A (1994) Identification and functional characterization of the bovine manganous superoxide dismutase promoter. Am J Respir Cell Mol Biol 10:113-21
Jones, M; Hoover, R; Meyrick, B (1992) Endotoxin enhancement of lymphocyte adherence to cultured sheep lung microvascular endothelial cells. Am J Respir Cell Mol Biol 7:81-9
Brigham, K L (1991) Oxygen radicals--an important mediator of sepsis and septic shock. Klin Wochenschr 69:1004-8
Meyrick, B; Christman, B; Jesmok, G (1991) Effects of recombinant tumor necrosis factor-alpha on cultured pulmonary artery and lung microvascular endothelial monolayers. Am J Pathol 138:93-101
Legrand, A B; Lawson, J A; Meyrick, B O et al. (1991) Substitution of 15-hydroxyeicosatetraenoic acid in the phosphoinositide signaling pathway. J Biol Chem 266:7570-7

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