STAT-1 and AP-1 decoy oligonucleotide therapy delays acute rejection and prolongs cardiac allograft survival

Acute myocardial rejection is a cell-mediated process characterized by increased leukocyte recruitment into the graft myocardial tissue. Transcription factors like STAT-1 and AP-1 are critically involved in this process by regulating vascular adhesion molecule expression. The aim of our study was to investigate the effect of decoy oligodeoxynucleotide (dODN) treatment targeting transcription factors AP-1 and STAT-1 on acute cardiac allograft rejection in a rat transplant model. Wistar-Furth (WF) cardiac allografts were transplanted into Lewis (LEW) rats after perfusion with STAT-1 or AP-1 dODN solution (5 micromol/l), buffer or the corresponding mutant control ODNs. Grafts were harvested and processed for histologic and immunohistochemical evaluation. As demonstrated by fluorescence dye-labelled dODN, exposure of the grafts to the dODNs during 45 min of warm ischemia resulted in a dominant uptake of naked DNA by the graft endothelium. Treatment with AP-1 and STAT-1 dODNs, but not with vehicle or the control dODNs, significantly prolonged cardiac allograft survival by approximately 40% from 5.6+/-0.5 days to 7.8+/-1.3 days and 7.4+/-0.5 days, respectively (mean+/-S.D., p