Antisense oligonucleotides to c-fos and c-jun inhibit intimal thickening in a rat vein graft model.
BACKGROUND
C-fos and c-jun are 2 immediate early genes that have been implicated in the stimulation of vascular smooth muscle cell proliferation and migration. In previous experiments in our laboratory with a rat vein graft model a 2- to 3-fold increase of messenger RNA of c-fos and c-jun were noted 1 hour after vein graft perfusion. Because c-fos and c-jun are up-regulated after the perfusion of vein grafts, the purpose of this study was to delineate the temporal expression of c-fos and c-jun protein and to study the effect of antisense oligonucleotides (ASO) to c-fos and c-jun on intimal thickening observed in this model.


METHODS
Sprague-Dawley rats underwent bilateral interposition femoral artery grafts with use of the superficial epigastric vein, which was harvested from 15 minutes up to 2 weeks and analyzed by Western blot for Fos and Jun protein. Additional rats underwent bypasses and at the time of the procedure 1 graft was treated with a pluronic gel containing an ASO to c-fos, c-jun, or sense and the contralateral side was treated with pluronic gel only. The vein grafts were harvested 2 weeks after the procedure and perfusion fixed. After longitudinal sectioning, the intimal and total wall thicknesses were measured in the perianastamotic and midgraft regions by a morphometric digitizing microscope and the statistics were analyzed by a paired Student's t test.


RESULTS
Protein analysis by Western blot showed that c-fos levels rose quickly within 2 hours and leveled at 6 hours 40-fold above basal levels after vein graft perfusion. Similarly, c-jun levels rose 10-fold above basal levels after 15 minutes and peaked at 2 hours 120-fold above basal levels. The treatment of the vein grafts with these ASOs resulted in a reduction of about 30% in the thickness of the intimal layer and the total wall thickness in both the perianastomotic and the midgraft regions, which was statistically significant different from control veins.


CONCLUSIONS
These results indicate a possible therapeutic role for ASO to immediate early genes in the treatment of vein graft intimal hyperplasia.
Suggs
W D
WD
Division of Vascular Surgery, Montefiore Medical Center, New York, NY 10467, USA.
Olson
S C
SC
Madnani
D
D
Patel
S
S
Veith
F J
FJ
Mandani
D
D
D000818:Animals; D006965:Hyperplasia; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000473:pathology*; D016376:Oligonucleotides, Antisense / Q000627:therapeutic use*; D016760:Proto-Oncogene Proteins c-fos / Q000037:antagonists & inhibitors*; D016755:Proto-Oncogene Proteins c-jun / Q000037:antagonists & inhibitors*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014680:Veins / Q000473:pathology* / Q000637:transplantation*
D016376:Oligonucleotides, Antisense; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun