c-Myc antisense oligonucleotides preserve smooth muscle differentiation and reduce negative remodelling following rat carotid arteriotomy.
OBJECTIVE
The vascular biology of restenosis is complex and not fully understood, thus explaining the lack of effective therapy for its prevention in clinical settings. The role of c-Myc in arteriotomy-induced stenosis, smooth muscle cell (SMC) differentiation and apoptosis was investigated in rat carotids applying full phosphorothioate antisense (AS) oligonucleotides (ODNs).


METHODS
Carotid arteries from WKY rats were submitted to arteriotomy and to local application of ODNs through pluronic gel. Apoptosis (deoxynucleotidyl transferase-mediated dUTP nick end-labelling), SMC differentiation (SM22 immunofluorescence) and vessel morphology and morphometry (image analysis) were determined 2, 5 and 30 days after injury, respectively.


RESULTS
AS ODNs induced a 60% decrease of target c-Myc mRNA 4 h after surgery in comparison to control sense (S) and scrambled ODN-treated carotids (p < 0.05). A significant 37 and 50% decrease in SM22 protein in the media of S ODN-treated and untreated carotids was detected when compared to uninjured contralateral arteries (p < 0.05). This reduction in SM22 expression was prevented in AS ODN-treated carotids. Stenosis was mainly due to adventitial constrictive remodelling. Lumen area in AS ODN-treated carotids was 35% greater than in control arteries 30 days after surgery (p < 0.05). TUNEL assay revealed increased apoptosis in AS ODN-treated carotids (p < 0.05).


CONCLUSIONS
c-Myc AS ODNs reduce arteriotomy-induced negative remodelling. This is accompanied by maintained SMC differentiation and greater apoptosis. The combination of reduced c-Myc-induced proliferation and increased apoptosis may thus underlie the less severe remodelling upon treatment with c-Myc mRNA AS ODN.
Forte
Amalia
A
Excellence Research Center for Cardiovascular Diseases, Department of Experimental Medicine, Second University of Naples, Via Constantinopoli 16, IT-80138 Naples, Italy.
Galderisi
Umberto
U
De Feo
Marisa
M
Gomez
Maria F
MF
Esposito
Salvatore
S
Santè
Pasquale
P
Renzulli
Attilio
A
Agozzino
Lucio
L
Hellstrand
Per
P
Berrino
Liberato
L
Cipollaro
Marilena
M
Cotrufo
Maurizio
M
Rossi
Francesco
F
Cascino
Antonino
A
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002339:Carotid Arteries / Q000378:metabolism / Q000473:pathology* / Q000601:surgery*; D002454:Cell Differentiation / Q000187:drug effects; D016259:Genes, myc; D008297:Male; D008840:Microfilament Proteins / Q000037:antagonists & inhibitors; D009124:Muscle Proteins / Q000037:antagonists & inhibitors; D009131:Muscle, Smooth, Vascular / Q000378:metabolism / Q000473:pathology*; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D011184:Postoperative Period; D012333:RNA, Messenger / Q000037:antagonists & inhibitors; D051381:Rats; D011921:Rats, Inbred WKY
D008840:Microfilament Proteins; D009124:Muscle Proteins; D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; C051615:transgelin