Objective: To study efficiency and security of the recombinant adenoviral-mediated gene transfer to the donor heart during the heart transplantation.
Methods: A total of 140 healthy male Wistar rats, aged 10 weeks, weighing 200-250 g, were equally divided into the donor group and the recipient group, and then 70 rats in the recipient group were randomly and equally divided into 2 subgroups: the gene transfer group and the control group. The rat model of heterotopic heart transplantation(Abdomen)was developed, the donor hearts were removed and their coronary arteries were perfused with 800 microl of the recombinant adenoviral vectors encoding the beta-galactosidase gene (Ad-LacZ). The grafts were stored in the 4 C cold saline solution for 30 minutes, and then the syngeneic transplant was performed. In the control group, saline of tales doses was perfused. The donor hearts were harvested at 3, 5, 7, 14, and 28 days (n = 7) after transplantation, and the beta-galactosidase activity was assessed by the X-gal staining. At 28 days the major organs of the recipients were tested by the histopathological analysis and the polymerase chain reaction of the adenoviral E1A sequences.
Results: The successful gene transfer of the beta-galactosidase gene was demonstrated in the adenovirus-perfused hearts, with no staining in the control group. The gene expression reached a peak level at 3, 5 and 7 days, and the averaged numbers of the total beta-galactosidase positive staining cells per slice were 66.4 +/- 23.1, 91.3 +/- 32.4 and 68.7 +/- 22.7, respectively, with no significant difference between the groups (P > 0.05). At 14 days the gene expression gradually declined (32.1+/-13.9), and the significant difference was found when compared with that at 3, 5 and 7 days (P< 0.05). At 28 days the cells positive for beta-galactosidase were sparse (3.9 +/- 3.4), and the gene transfer was significantly less efficient compared with that at 3, 5, 7 and 14 days (P<0.05). The major organs of the recipients were not affected seriously at 28 days. No virus spread to other organs in this experimental protocol.
Conclusion: The ex vivo adenoviral-mediated gene transfer intracoronarily to the donor heart during the heart transplantation is feasible and safe.