Endothelial healing in vein grafts: proliferative burst unimpaired by genetic therapy of neointimal disease.
BACKGROUND
Although inhibition of neointimal hyperplasia by cell cycle gene blockade therapy results in improved endothelial cell function in experimental vein grafts, little is known either about endothelial healing immediately after vein grafting or about the effect of this therapy on the healing process.


RESULTS
Scanning electron microscopy demonstrated an immediate decrease in vein graft endothelial cell density associated with vein graft wall stretch, followed by a return to baseline by postoperative day 3. En face detection of bromodeoxyuridine incorporation confirmed a rapid endothelial proliferation by 48 hours. Despite inhibition of underlying vascular smooth muscle cell proliferation, E2F decoy oligonucleotide did not inhibit either endothelial bromodeoxyuridine incorporation or the return to baseline cell density. This differential response to E2F decoy was also observed in human umbilical vein endothelial cell culture, which resisted the E2F decoy inhibition of cell growth that was observed in human umbilical artery smooth muscle cells, despite evidence for nuclear localized delivery of the oligonucleotide into both cell types. Furthermore, the reduction of E2F binding activity seen in a nuclear gel shift assay of cultured smooth muscle cells was not observed in endothelial cells.


CONCLUSIONS
These results suggest a burst of graft endothelial cell proliferation that allows a rapid restoration of cell density in the monolayer. Additionally, there is a selective effect of E2F decoy gene therapy on target smooth muscle cells with sparing of this endothelial healing.
Ehsan
Afshin
A
Department of Medicine, Harvard Medical School and Brigham and Women's Hospital, Boston, Mass 02115, USA.
Mann
Michael J
MJ
Dell'Acqua
Giorgio
G
Tamura
Koichi
K
Braun-Dullaeus
Ruediger
R
Dzau
Victor J
VJ
D000818:Animals; D001973:Bromodeoxyuridine; D002339:Carotid Arteries / Q000601:surgery; D002452:Cell Count; D002453:Cell Cycle / Q000187:drug effects; D018797:Cell Cycle Proteins; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004268:DNA-Binding Proteins; D004195:Disease Models, Animal; D050684:E2F Transcription Factors; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D015316:Genetic Therapy; D006083:Graft Occlusion, Vascular / Q000473:pathology / Q000503:physiopathology / Q000517:prevention & control*; D007150:Immunohistochemistry; D007601:Jugular Veins / Q000187:drug effects* / Q000473:pathology / Q000637:transplantation; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D009841:Oligonucleotides / Q000008:administration & dosage*; D018809:Proliferating Cell Nuclear Antigen / Q000096:biosynthesis; D011817:Rabbits; D014157:Transcription Factors / Q000037:antagonists & inhibitors; D014162:Transfection; D016896:Treatment Outcome; D014945:Wound Healing / Q000187:drug effects / Q000235:genetics
D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D009841:Oligonucleotides; D018809:Proliferating Cell Nuclear Antigen; D014157:Transcription Factors; D001973:Bromodeoxyuridine