The lectin-like domain of tumor necrosis factor improves lung function after rat lung transplantation--potential role for a reduction in reactive oxygen species generation.
OBJECTIVE
To test the hypothesis that the lectin-like domain of tumor necrosis factor, mimicked by the TIP peptide, can improve lung function after unilateral orthotopic lung isotransplantation. Because of a lack of a specific treatment for ischemia reperfusion-mediated lung injury, accompanied by a disrupted barrier integrity and a dysfunctional alveolar liquid clearance, alternative therapies restoring these parameters after lung transplantation are required.


METHODS
Prospective, randomized laboratory investigation.


METHODS
University-affiliated laboratory.


METHODS
Adult female rats.


METHODS
Tuberoinfundibular peptide, mimicking the lectin-like domain of tumor necrosis factor, mutant TIP peptide, N,N'-diacetylchitobiose/TIP peptide, and amiloride/TIP peptide were instilled intratracheally in the left lung immediately before the isotransplantation was performed. An additional group received an intravenous TIP peptide treatment, 1.5 mins before transplantation. Studies using isolated rat type II alveolar epithelial cell monolayers and ovine pulmonary endothelial cells were also performed.


RESULTS
Intratracheal pretreatment of the transplantable left lung with the TIP peptide, but not with an inactive mutant TIP peptide, resulted in significantly improved oxygenation 24 hrs after transplantation. This treatment led to a significantly reduced neutrophil content in the lavage fluid. Both the effects on oxygenation and neutrophil infiltration were inhibited by the epithelial sodium channel blocker amiloride. The TIP peptide blunted reactive oxygen species production in pulmonary artery endothelial cells under hypoxia and reoxygenation and reduced reactive oxygen species content in the transplanted rat lungs in vivo. Ussing chamber experiments using monolayers of primary type II rat pneumocytes indicated that the primary site of action of the peptide was on the apical side of these cells.


CONCLUSIONS
These data demonstrate that the TIP peptide significantly improves lung function after lung transplantation in the rat, in part, by reducing neutrophil content and reactive oxygen species generation. These studies suggest that the TIP peptide is a potential therapeutic agent against the ischemia reperfusion injury associated with lung transplantation.
Hamacher
Jürg
J
Internal Medicine V - Pulmonary Division, University Hospital Homburg, Homburg, Germany.
Stammberger
Uz
U
Roux
Jeremie
J
Kumar
Sanjiv
S
Yang
Guang
G
Xiong
Chenling
C
Schmid
Ralph A
RA
Fakin
Richard M
RM
Chakraborty
Trinad
T
Hossain
Hamid M D
HM
Pittet
Jean-François
JF
Wendel
Albrecht
A
Black
Stephen M
SM
Lucas
Rudolf
R
D056809:Alveolar Epithelial Cells / Q000187:drug effects / Q000502:physiology; D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D004187:Disaccharides / Q000494:pharmacology; D042783:Endothelial Cells / Q000187:drug effects / Q000502:physiology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000503:physiopathology; D008168:Lung / Q000098:blood supply*; D016040:Lung Transplantation / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009479:Neuropeptides / Q000494:pharmacology*; D010100:Oxygen / Q000502:physiology; D011650:Pulmonary Alveoli / Q000187:drug effects / Q000503:physiopathology; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015427:Reperfusion Injury / Q000503:physiopathology*; D012129:Respiratory Function Tests; D012756:Sheep; D026941:Sodium Channel Blockers / Q000494:pharmacology; D013481:Superoxides / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D004187:Disaccharides; D009479:Neuropeptides; D017382:Reactive Oxygen Species; D026941:Sodium Channel Blockers; D014409:Tumor Necrosis Factor-alpha; C400136:tuberoinfundibular peptide 39; D013481:Superoxides; C010913:N,N-diacetylchitobiose; D000584:Amiloride; D010100:Oxygen