ABSTRACT
BACKGROUND: Understanding the precise molecular mechanisms underlying the phenomenon of restenosis after PTCA may help us to develop a new strategy for the treatment of restenosis after PTCA. The purpose of this study was to identify the genes involved in vascular restenosis. METHODS AND RESULTS: Applying a differential hybridization method to a model of the balloon-injured rabbit aorta, we identified 6 cDNA clones that were upregulated after injury. Northern blot showed that 5 genes, but not apolipoprotein J (apoJ)/clusterin, were constitutively expressed in noninjured aorta and upregulated after balloon injury. ApoJ mRNA was not detectable in noninjured aorta (control), began to be expressed at 6 hours after injury, showed a peak level at 24 hours (a 48-fold increase), gradually declined, and returned to the control level at 24 weeks. Western blot and immunohistochemistry demonstrated no expression of apoJ protein in noninjured aorta, an expression of apoJ at 2 days after balloon injury, and a peak level (a 55-fold increase) at 2 to 8 weeks. The expression of apoJ protein continued until 24 weeks after injury. In situ hybridization revealed that apoJ mRNA was expressed in smooth muscle cells (SMCs) of media at 2 days after injury and in SMCs of media and neointima at 2 weeks. To analyze the function of apoJ, stably transfected rabbit SMCs were created. The expression of apoJ stimulated proliferation and migration of SMCs. CONCLUSIONS: ApoJ is dramatically induced in media and neointima after vascular injury, suggesting that apoJ contributes to restenosis after angioplasty.
Subject(s)
Aorta/metabolism , Aortic Diseases/metabolism , Glycoproteins/biosynthesis , Glycoproteins/genetics , Molecular Chaperones/biosynthesis , Molecular Chaperones/genetics , Muscle, Smooth, Vascular/metabolism , Angioplasty, Balloon, Coronary/adverse effects , Animals , Aorta/injuries , Aorta/pathology , Aortic Diseases/etiology , Aortic Diseases/pathology , Blotting, Western , Cell Division/drug effects , Cell Movement/drug effects , Cells, Cultured , Clusterin , Disease Models, Animal , Gene Expression Profiling , Gene Expression Regulation , Glycoproteins/pharmacology , Immunohistochemistry , In Situ Hybridization , Male , Molecular Chaperones/pharmacology , Molecular Sequence Data , Muscle, Smooth, Vascular/cytology , Muscle, Smooth, Vascular/drug effects , RNA, Messenger/biosynthesis , Rabbits , Sequence Analysis, DNAABSTRACT
To determine the relation between the concentration of lipoprotein(a) [Lp(a)] and restenosis after percutaneous transluminal coronary angioplasty (PTCA) in Japan, we studied 80 consecutive patients with single-vessel disease who successfully underwent PTCA. All were evaluated by follow-up angiography a mean of 6.9 months after PTCA and were divided into the restenosis (30 patients) and the non-restenosis (50 patients) groups. The serum Lp(a) concentration of 29 +/- 17 mg/dl in the restenosis group was significantly higher than that of 17 +/- 14 mg/dl in the nonrestenosis group (p < 0.01). Multiple logistic regression analysis for risk factors revealed a significant correlation between restenosis and Lp(a) (p < 0.003). The serum Lp(a) concentration was positively correlated with the coronary artery percent stenosis at the time of follow-up angiography (r = 0.32, p < 0.01). High serum concentration of Lp(a) is therefore a risk factor for restenosis after PTCA in Japan.
Subject(s)
Angioplasty, Balloon, Coronary , Coronary Disease/blood , Coronary Disease/therapy , Lipoprotein(a)/blood , Adult , Aged , Constriction, Pathologic , Coronary Disease/ethnology , Female , Humans , Japan , Logistic Models , Male , Middle Aged , Prospective Studies , Recurrence , Risk FactorsABSTRACT
We investigated whether induction of transcription factor NF-kappa B is involved in the proliferation of cultured rat aortic smooth muscle cell using electrophoretic mobility shift assay and immunocytochemistry. NF-kappa B was induced in the nucleus in a dose-dependent manner when the smooth muscle cells were stimulated by various growth factors such as PDGF-BB, bFGF, EGF and IGF-1, but not growth inhibitors such as TGF-beta and IFN-gamma. Among growth factors, PDGF-BB and bFGF, more potent growth stimulators, induced higher kappa B binding activity than EGF or IGF-1. These evidences were also supported by the results obtained with immunocytochemistry. Immunocytochemistry also showed that the induced NF-kappa B contained p50 and p65. These results suggest that NF-kappa B induction may be involved in the proliferation of vascular smooth muscle cell.
Subject(s)
Cell Nucleus/metabolism , Growth Substances/pharmacology , Muscle, Smooth, Vascular/metabolism , NF-kappa B/biosynthesis , Animals , Aorta , Base Sequence , Cell Division/drug effects , Cell Nucleus/drug effects , Cells, Cultured , DNA Primers , DNA Probes , Enhancer Elements, Genetic , Humans , Molecular Sequence Data , Muscle, Smooth, Vascular/cytology , Muscle, Smooth, Vascular/drug effects , Oligodeoxyribonucleotides , Rats , Receptors, Interleukin-2/biosynthesisABSTRACT
We investigated the effect of lipoprotein(a) (Lp(a)) on proliferation of human arterial smooth muscle cells (SMCs) and its mechanisms of action. Low density lipoprotein (LDL), Lp(a) and apolipoprotein(a) (apo(a)) significantly stimulated the proliferation of SMCs. Lp(a) and apo(a) reduced the amount of active transforming growth factor-beta (TGF-beta) with the mink lung epithelial cell bioassay, however LDL had no effect. Lp(a), but not apo(a), significantly stimulated the proliferation of SMCs even in the presence of a neutralizing antibody for TGF-beta. Our results suggest that Lp(a) stimulates the proliferation of SMCs via apo(a)-induced inhibition of TGF-beta activation and stimulation of SMCs by the LDL-particle of Lp(a).
