PREVENTION OF ISCHEMICALLY INDUCED NEOINTIMAL HYPERPLASIA USING EX-VIVO ANTISENSE OLIGODEOXYNUCLEOTIDES

Background: Chronic graft vascular disease in cardiac allografts resul ts from coronary artery neointimal formation. Vascular ischemia has be en shown to provoke the development of neointimal hyperplasia through endothelial damage. We used a rodent model of neointimal formation to test the in vivo effects of antisense oligodeoxynucleotides (AS ODN) s pecifically designed to block this process. Methods: Aortas from ACI r ats were mock transfected or transfected with 18 base pair AS ODNs aga inst the 5' start codon region of both CDC2 kinase, and proliferating cell nuclear antigen (PCNA) mRNA. Transfection was accomplished by pla cing the aorta in ODN solution (transfected group, 40 mu mol/L of each sequence) or saline solution alone (mock-transfected group) and expos ing to hydrostatic pressure (2 atm) for 24 hours at 4 degrees C. Vesse ls were then interposition-grafted into the abdominal aorta of untreat ed isogenic recipients and procured on postoperative days (POD) 1, 6, and 14. Results: Nuclear localization of fluorescein isothiocyanate OD N was observed in 81% +/- 3% of medial smooth muscle cells at 24 hours after interposition grafting and reperfusion. Efficacy of AS ODNs at blocking CDC2 kinase and PCNA was verified on POD 6 by enzyme-linked i mmunosorbent assay. This blockade significantly reduced ischemically i nduced vascular narrowing on POD 14 as assessed by use of computerized image analysis (3.85% +/- 2.45% luminal narrowing for transfected vs 7.11% +/- 2.03% for control subjects, p < 0.03). Conclusions: Our data show the efficacy of AS ODN at blocking rat PCNA and CDC2 kinase up-r egulation provoked by ischemia. This ex vivo approach had beneficial e ffects against vascular narrowing in a rodent model of ischemically in duced neointimal hyperplasia, an antigen-independent factor important in the development of subsequent chronic graft vascular disease.