Background. Nuclear factor-κB (NF-κB) is a transcription factor that upregulates adhesion molecules ICAM-1, VCAM-1, and ELAM-1. We hypothesized the use of ex vivo pressure-mediated delivery of transcription factor decoys (TFD) to NF-κB binding sites would decrease expression of adhesion molecules, and decrease reperfusion injury, acute rejection, and graft coronary artery disease (GCAD) in rat cardiac allografts. Methods. Heterotopic heart transplants were performed on donor hearts treated with saline, 10 mg/kg LPS, 160 μmol/L NF-κB TFD, or 160 μmol/L scrambled sequence (NF-SC) TFD for 45 min at 78 psi (6 atm). Transfection efficiency was determined with FITC-labeled TFD. Reverse transcription-PCR and immunohistochemistry was used to analyze adhesion molecule mRNA and protein expression, respectively. Apoptosis was measured with DNA fragmentation analysis. Reperfusion injury was assessed with cardiac edema, neutrophil infiltration, and histology. Acute rejection was determined by daily palpation. Allografts were assessed at POD 90 for the development of GCAD by computer-assisted image analysis to determine intimal: medial ratio and myointimal proliferation. Results. Hyperbaric pressure was an effective method of NF-κB TFD delivery (P<0.001 vs. controls). NF-κB TFD treatment led to decreased mRNA and protein expression of adhesion molecules. Treatment with NF-κB TFD led to a significant decrease in all reperfusion injury parameters compared to saline and NF-SC controls (P<0.01 vs. controls). Higher levels of apoptosis were seen in allografts treated with NF-κB TFD compared to control allografts. NF-κB TFD treatment prolonged allograft survival over saline and NF-SC controls (P<0.05). Myointimal proliferation and intimal: medial ratios in NF-κB TFD-treated allografts were significantly decreased compared to saline and NF-SC treatment (P<0.00001). Conclusions. Ex vivo pressure-mediated delivery of NF-κB TFD is an effective method to block adhesion molcule expression and reperfusion injury in the immediate posttransplant period. Further, NF-κB TFD treatment prolongs allograft survival and decreases GCAD.
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