Adenovirus-mediated gene transfer to human cerebral arteries

Gene therapy is being investigated as a putative treatment option for cardi ovascular diseases, including cerebral vasospasm. Because there is presentl y no information regarding gene transfer to human cerebral arteries, the pr incipal objective of this study was to characterize adenovirus-mediated exp ression and function of recombinant endothelial nitric oxide synthase (eNOS ) gene in human pial arteries. Pial arteries (outer diameter 500 to 1000 mu m) were isolated from 30 patients undergoing temporal lobectomy for intrac table seizures and were studied using histologic staining, histochemistry, electron microscopy, and isometric force recording. Gene transfer experimen ts were performed ex vivo using adenoviral vectors encoding genes for bovin e eNOS (AdCMVeNOS) and Escherichia coli beta-galactosidase (AdCMVLacZ). In transduced arteries, studied 24 hours after exposure to vectors, expression of recombinant beta-galactosidase and eNOS was detected by histochemistry, localizing mainly to the adventitia (n = 4). Immunoelectron microscopy loc alized recombinant eNOS in adventitial fibroblasts. During contractions to U46619, bradykinin-induced relaxations were significantly augmented in AdCM VeNOS-transduced rings compared with control and AdCMVLacZ-transduced rings (P < 0.01; n = 6). The NOS inhibitor L-nitroarginine methylester (L-NAME) caused significantly greater contraction in AdCMVeNOS-transduced rings (P < 0.001; n = 4) and inhibited bradykinin-induced relaxations in control and transduced rings (P < 0.001; n = 6). The current findings suggest that in A dCM/VeNOS-transduced human pial arteries, expression of recombinant eNOS oc curs mainly in adventitial fibroblasts where it augments relaxations to NO- dependent agonists such as bradykinin. Findings from the current study migh t be beneficial in future clinical applications of gene therapy for the tre atment or prevention of cerebral vasospasm.