title: Chimeric DNA-RNA hammerhead ribozyme targeting PDGF A-chain mRNA specifically inhibits neointima formation in rat carotid artery after balloon injury.
abstract: OBJECTIVE
  Restenosis of the coronary artery after percutaneous transluminal coronary angioplasty (PTCA) occurs in 30-50% of patients and remains a major clinical problem. We developed ribozyme that targets platelet-derived growth factor (PDGF) A-chain mRNA as a gene therapy for restenosis after PTCA. Thus, we examined the effects of a chimeric DNA-RNA ribozyme targeting PDGF A-chain mRNA on neointima formation in rat carotid artery after balloon injury and evaluated its specificity for PDGF A-chain mRNA by microarray analysis.
  
  
  METHODS
  Rat carotid artery was injured with a 2F Fogarty catheter, and PDGF A-chain specific ribozyme was delivered to the injured artery with polyethylenimine. Two weeks after injury, the artery was removed, and the intima/media (I/M) ratio was evaluated. Six hours after injury, mRNA was extracted with oligo dT cellulose, and expression of PDGF A-chain mRNA was evaluated by reverse transcription-polymerase chain reaction. Expression of PDGF-AA protein was evaluated by Western blot analysis. Expression of 970 genes was evaluated by microarray (GeneChip, Affimetrix Inc).
  
  
  RESULTS
  FITC-labeled ribozyme was taken up into the midlayer smooth muscle of the carotid artery until 24 h after balloon injury. Two and 5 microg of ribozyme significantly reduced neointima formation by 44 and 55% of control levels, respectively, in a dose-dependent manner. Ribozyme markedly inhibited expression of PDGF A-chain mRNA as well as production of PDGF-AA protein in injured vessels. Microarray analysis revealed that expression of 525 genes was increased after balloon injury. These genes included FLK-1, interleukin-1 receptor, retinoic acid receptor alpha2 isoform, heat shock protein, MAP kinase kinase, Fas antigen, G6Pase, PI-5-P-kinase, p38 MAP kinase, proliferating cell nuclear antigen, transforming growth factor-beta, extracellular signal-related kinase, and fibroblast growth factor receptor. With respect to expression of cytokine and growth factor mRNAs, the best ribozyme specifically inhibited expression of PDGF A-chain mRNA.
  
  
  CONCLUSIONS
  Our chimeric DNA-RNA hammerhead ribozyme targeting PDGF A-chain mRNA inhibited neointima formation in rat carotid artery after balloon injury with specific inhibition of expression of PDGF A-chain mRNA, suggesting that this ribozyme may be useful for therapy of restenosis of coronary artery after PTCA.
authors.affiliation: Second Department of Internal Medicine, Nihon University School of Medicine, Tokyo 173-8610, Japan.
authors.forename: Motoko
authors.initials: M
authors.lastname: Kotani
authors.forename: Noboru
authors.initials: N
authors.lastname: Fukuda
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Ando
authors.forename: Wen-Yang
authors.initials: WY
authors.lastname: Hu
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kunimoto
authors.forename: Satoshi
authors.initials: S
authors.lastname: Saito
authors.forename: Katsuo
authors.initials: K
authors.lastname: Kanmatsuse
mesh_terms: D000818:Animals; D002339:Carotid Arteries / Q000473:pathology*; D016893:Carotid Stenosis / Q000209:etiology* / Q000473:pathology / Q000628:therapy; D002404:Catheterization / Q000009:adverse effects*; D015870:Gene Expression; D015316:Genetic Therapy / Q000379:methods*; D006133:Growth Substances / Q000235:genetics; D008297:Male; D020411:Oligonucleotide Array Sequence Analysis; D010982:Platelet-Derived Growth Factor / Q000032:analysis / Q000235:genetics*; D016337:RNA, Catalytic / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D014162:Transfection / Q000379:methods; D017539:Tunica Intima / Q000473:pathology*
chemical_list: D006133:Growth Substances; D010982:Platelet-Derived Growth Factor; D016337:RNA, Catalytic; C075278:platelet-derived growth factor A