Intratracheal poly (ADP) ribose synthetase inhibition ameliorates lung ischemia reperfusion injury.
BACKGROUND
We previously demonstrated that intravenous poly (ADP) ribose synthetase (PARS) inhibition protects against experimental lung ischemia reperfusion injury (LIRI) in an in situ, hilar occlusion model. This study determined its efficacy when administered intratracheally (IT).


METHODS
Left lungs of rats were rendered ischemic for 90 minutes, and reperfused for up to 4 hours. Treated animals received INO-1001, a PARS inhibitor, intratracheally 30 minutes before ischemia, while controls were given IT vehicle at equivalent volumes. All groups contained at least 4 animals. Lung injury was quantitated utilizing vascular permeability to radiolabeled albumin, tissue myeloperoxidase (MPO) content, alveolar leukocyte cell counts, and arterial pO(2) at 4 hours of reperfusion. Electrophoretic mobility shift assays (EMSA) assessed the nuclear translocation of NFkappaB and AP-1 in injured left lungs, while ELISAs quantitated secreted cytokine induced neutrophil chemoattractant (CINC) and MCP-1 protein in bronchoalveolar lavage fluid.


RESULTS
Intratracheal PARS inhibition was 73% (p < 0.0001) and 87% (p < 0.0001) protective against increases in vascular permeability and alveolar leukocyte accumulation, respectively, and improved arterial pO(2) (p < 0.0004) at 4 hours of reperfusion. Myeloperoxidase (MPO) activity in treated lungs was reduced by 70% (p < 0.02). The nuclear translocation of NFkappaB and AP-1 was attenuated at 15 minutes of reperfusion, and the secretion of CINC and MCP-1 (p < 0.05) protein into the alveolus was diminished at 4 hours of reperfusion.


CONCLUSIONS
Intratracheal INO-1001 protects against experimental LIRI. The reduction in secreted chemokine protein at 4 hours of reperfusion appears to be mediated at the pretranscriptional level through attenuated NFkappaB and AP-1 activation. This route may optimize future donor organ management and improve lung recipient outcomes.
Farivar
Alexander S
AS
Department of Surgery, University of Washington Medical Center, Seattle, Washington 98195, USA. afarivar@u.washington.edu
Woolley
Steven M
SM
Fraga
Charles H
CH
Thomas
Robert
R
Salzman
Andrew L
AL
Szabo
Csaba
C
Mulligan
Michael S
MS
D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D002199:Capillary Permeability; D019743:Chemokines, CXC / Q000032:analysis; D024202:Electrophoretic Mobility Shift Assay; D004791:Enzyme Inhibitors / Q000008:administration & dosage; D036341:Intercellular Signaling Peptides and Proteins / Q000032:analysis; D007442:Intubation, Intratracheal; D008168:Lung / Q000098:blood supply* / Q000378:metabolism; D016328:NF-kappa B / Q000032:analysis; D010100:Oxygen / Q000097:blood; D009195:Peroxidase / Q000032:analysis; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D011838:Radiation-Sensitizing Agents / Q000008:administration & dosage*; D051381:Rats; D020318:Rats, Long-Evans; D015427:Reperfusion Injury / Q000378:metabolism / Q000517:prevention & control*; D018808:Transcription Factor AP-1 / Q000032:analysis
D019743:Chemokines, CXC; D004791:Enzyme Inhibitors; D036341:Intercellular Signaling Peptides and Proteins; D016328:NF-kappa B; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D011838:Radiation-Sensitizing Agents; D018808:Transcription Factor AP-1; D009195:Peroxidase; D010100:Oxygen