Poly (ADP) ribose synthetase inhibition reduces obliterative airway disease in rat tracheal allografts.
BACKGROUND
Obliterative bronchiolitis (OB) is the major long-term complication affecting lung transplant recipients, and is characterized pathologically by chronic inflammatory and fibroproliferative airway disease. Based on studies revealing anti-inflammatory and anti-apoptotic properties of poly (ADP)-ribose synthetase (PARS) inhibitors, we hypothesized that their administration would be protective in a heterotopic model of experimental OB.


METHODS
We transplanted rat tracheas from Brown-Norway donors into Lewis recipients, and treated 2 groups with a novel PARS inhibitor, INO-1001. One group received 14 days of treatment, whereas a second received delayed treatment beginning on Day 7 post-transplant. Tracheas were analyzed by light microscopy and computerized morphometry. Effects on cytokine transcription, nuclear transcription factor activation and cellular death were assessed by in situ hybridization for tumor necrosis factor-alpha (TNF-alpha), electromobility shift assays for nuclear factor-kappaB (NF-kappaB) and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assays, respectively.


RESULTS
PARS inhibition significantly decreased luminal obstruction (p < 0.001) and enhanced preservation of epithelial lining (p < 0.001) at 14 days post-transplant. Day 7 controls confirmed the development of an obstructive lesion in the lumen, averaging 28% occlusion. Delayed treatment (beginning on Day 7) arrested (p < 0.001) progression of the established lesion. Allograft airways treated with INO-1001 demonstrated attenuated NF-kappaB nuclear translocation, reduced transcription of TNF-alpha mRNA, and decreased cellular death on TUNEL and caspase 3 staining.


CONCLUSIONS
PARS inhibition is anti-inflammatory, protects against experimental OB, and is associated with enhanced preservation of respiratory epithelium and decreased cellular death. Delayed treatment with INO-1001 arrests progression of the lesion developed by Day 7. These studies suggest that activation of PARS plays a critical role in the development of airway obliterative disease.
Department of Surgery, Division of Cardiothoracic Surgery, University of Washington Medical Center, 1959 NE Pacific Street, Seattle, WA 98195, USA. afarivar@u.washington.edu
Alexander S
AS
Farivar
Steven M
SM
Woolley
Babu V
BV
Naidu
Charles H
CH
Fraga
Karen
K
Byrne
Robert
R
Thomas
Andrew L
AL
Salzman
Csaba S
CS
Szabo
Michael S
MS
Mulligan
D000818:Animals; D001989:Bronchiolitis Obliterans / Q000188:drug therapy* / Q000378:metabolism; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D017403:In Situ Hybridization; D020287:In Situ Nick-End Labeling; D007211:Indoles / Q000494:pharmacology*; D008297:Male; D023421:Models, Animal; D016328:NF-kappa B / Q000032:analysis / Q000378:metabolism; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D011183:Postoperative Complications / Q000188:drug therapy; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011917:Rats, Inbred Lew; D014132:Trachea / Q000378:metabolism* / Q000473:pathology / Q000637:transplantation; D014184:Transplantation, Homologous; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
C491685:INO 1001; D007211:Indoles; D016328:NF-kappa B; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; D011065:Poly(ADP-ribose) Polymerases; C505410:Casp3 protein, rat; D053148:Caspase 3; D020169:Caspases