The research plan explores fundamental questions related to the role of nitric oxide (NO) in cytokine-induced lung injury. Derangements in pulmonary vasomotor and endothelial function are prominent in this pathophysiology. Many of these sequelae are reproduced by the inflammatory cytokines which in turn influence the production of NO by constitutive (cNOS) and inducible (iNOS) nitric oxide synthases. The role of these isoforms, however, is not clear. Nonspecific inhibition of the enzymes has yielded both beneficial and injurious results. Our overall hypothesis is that transient cytotoxic NO production by iNOS mediates cellular dysfunction and damage while continued physiologic production of NO by cNOS maintains homeostasis and is protective during cytokine induced lung injury. We first evaluate cultures of pulmonary arterial microvascular smooth muscle and endothelial cells where cytokine stimulated NO synthase expression and associated cytotoxicity are defined. We then selectively alter NO production by the different isoforms and evaluate the resulting cytotoxicity and cellular dysfunction. Specifically, we inhibit iNOS in cytokine exposed cultures with aminoguanidine and anti sense oligonucleotides, and we simulate iNOS induction in cultures without cytokines by iNOS transfection and the addition of the NO donor S-nitroso-N-acetylpencillamine. In parallel, we inhibit cNOS in cytokine exposed cultures with antisense oligonucleotides and L-N(omega)-nitroarginine, and we stimulate cNOS activity by transfection.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Clinical Investigator Award (CIA) (K08)
Project #
5K08HL003018-03
Application #
2444993
Study Section
Special Emphasis Panel (ZHL1-CSR-Y (F1))
Project Start
1995-07-01
Project End
2000-06-30
Budget Start
1997-07-01
Budget End
1998-06-30
Support Year
3
Fiscal Year
1997
Total Cost
Indirect Cost
Name
University of Pittsburgh
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
053785812
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Erukhimov, J A; Tang, Z L; Johnson, B A et al. (2000) Actin-containing sera from patients with adult respiratory distress syndrome are toxic to sheep pulmonary endothelial cells. Am J Respir Crit Care Med 162:288-94
Johnson, B A; Pitt, B R; Davies, P (2000) Pulmonary arterial smooth muscle cells modulate cytokine- and LPS-induced cytotoxicity in endothelial cells. Am J Physiol Lung Cell Mol Physiol 278:L460-8