Localization of c-Myb and induction of apoptosis by antisense oligonucleotide c-Myb after angioplasty of porcine coronary arteries.
Previous studies have shown that inhibition of the proto-oncogene c-myb inhibits neointimal formation in various animal models. However, the temporal and spatial expression of c-Myb in the vessel wall after injury is not known, and the mechanism of action of antisense oligonucleotide (AS-ODN-c-myb) inhibition remains unclear. One potential effect of cell cycle dysregulation by inhibition of c-myb is an increase in the rates of apoptosis. In this study, c-Myb expression after percutaneous transluminal coronary angioplasty (PTCA) injury and induction of apoptosis after AS-ODN-c-myb treatment were determined. Immunohistochemistry and cellular phenotyping were used to localize c-Myb expression in porcine coronary arteries at various time intervals after PTCA. In vitro, the effects of AS-ODN-c-myb on the apoptosis of porcine vascular smooth muscle cells (PVSMCs) and endothelial cells were determined by using a cell-death ELISA and time-lapse video microscopy. In vivo, local delivery of AS-ODN-c-myb was performed after PTCA of pig coronary arteries, and apoptosis was quantified at 6 hours. c-Myb is induced in pig coronary arteries after angioplasty, with maximal expression in inflammatory cells at 18 hours and in vascular smooth muscle cells at 3 to 7 days. In vitro, AS-ODN-c-myb enhanced PVSMCs (6.8+/-0.8% [P=<0.001] versus 0.5% serum) but not endothelial cell apoptosis (1.4+/-0.5% [P=NS] versus 0.5% serum). In vivo, 6 hours after porcine coronary angioplasty and delivery of AS-ODN-c-myb, the proportion of apoptotic cells within the media was 4.2+/-0.8% (PTCA alone), 2.3+/-0.2% (PTCA+vehicle), and 9.0+/-1.1% (PTCA+AS-ODN-c-myb; P<0.05 versus PTCA alone and P<0.01 versus PTCA+saline). c-Myb is expressed after PTCA of pig coronary arteries, and AS-ODN-c-myb induces apoptosis of PVSMCs in vitro and medial cells in vivo.
Lambert
D L
DL
Cardiovascular Research Group, Division of Clinical Sciences, University of Sheffield, Sheffield, UK.
Malik
N
N
Shepherd
L
L
Gunn
J
J
Francis
S E
SE
King
A
A
Crossman
D C
DC
Cumberland
D C
DC
Holt
C M
CM
D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects*; D000818:Animals; D017209:Apoptosis; D015415:Biomarkers / Q000032:analysis; D002478:Cells, Cultured; D023903:Coronary Restenosis / Q000209:etiology; D003331:Coronary Vessels / Q000166:cytology* / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D020287:In Situ Nick-End Labeling; D007700:Kinetics; D018715:Microscopy, Video; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D010641:Phenotype; D020598:Proto-Oncogene Proteins c-myb / Q000235:genetics / Q000378:metabolism*; D013552:Swine
D015415:Biomarkers; D016376:Oligonucleotides, Antisense; D020598:Proto-Oncogene Proteins c-myb