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Biomedical subjects

Kyung-Woo Park

Publications and source records attributed to Kyung-Woo Park.

At least 19 recordsLinked to original sources
PubMed2006

Beta-catenin overexpression reduces myocardial infarct size through differential effects on cardiomyocytes and cardiac fibroblasts.

Beta-catenin is a transcriptional regulator of several genes involved in survival and proliferation. Although previous studies suggest that beta-catenin may be involved in the process of preconditioning and healing after myocardial infarction (MI), little is known regarding the role of beta-catenin in cardiomyocytes and cardiac fibroblasts. We investigated the role of beta-catenin in cardiomyocytes and cardiac fibroblasts and whether beta-catenin overexpression could reduce MI size. Adenovirus-mediated gene transfer of nonphosphorylatable constitutively active beta-catenin (Ad-catenin) decreased apoptosis in cardiomyocytes and cardiac fibroblasts with increased expression of survivin and Bcl-2. Although Ad-catenin increased the percentage of cells in the S phase with enhanced expression of cyclin D1 and E2 in both cell types, the increase in cell number was only evident in cardiac fibroblasts, whereas hypertrophy and binuclear cells were more prominent in cardiomyocytes. All of these effects of beta-catenin gene transfer were blocked by inhibition of its nuclear translocation. Furthermore, Ad-catenin enhanced the expression of vascular endothelial growth factor in both cells and induced differentiation of cardiac fibroblasts into myofibroblasts. In a rat MI model, injection of Ad-catenin into the infarct border zone resulted in a significantly decreased MI size with anti-apoptotic effect and cell cycle activation in both cardiomyocytes and myofibroblasts. beta-Catenin may play an important role in the healing process after MI by promoting survival and cell cycle not only in cardiomyocytes but also in cardiac fibroblasts with its differentiation into myofibroblasts.

Animals↗
PubMed2006

Differential effect of intracoronary infusion of mobilized peripheral blood stem cells by granulocyte colony-stimulating factor on left ventricular function and remodeling in patients with acute myocardial infarction versus old myocardial infarction: the MAGIC Cell-3-DES randomized, controlled trial.

BACKGROUND: The efficacy of intracoronary infusion of granulocyte colony-stimulating factor (G-CSF) mobilized peripheral blood stem cells (PBSCs) has not been compared between patients with acute (AMI) versus old myocardial infarction (OMI). In addition, the potential risk of restenosis associated with G-CSF-based stem cell therapy has not been evaluated in the setting of drug eluting stent (DES) implantation. METHODS AND RESULTS: We randomly allocated 96 patients with myocardial infarction who underwent coronary revascularization with DES for the culprit lesion into 4 groups. Eighty-two patients completed 6-month follow-up; AMI cell infusion (n=25), AMI control (n=25), OMI cell infusion (n=16), and OMI control group (n=16). In cell infusion groups, PBSCs were mobilized by G-CSF for 3 days and delivered to infarcted myocardium via intracoronary infusion. The AMI cell infusion group showed a significant additive improvement in left ventricular ejection fraction (LVEF) and remodeling compared with controls (change of LVEF: +5.1+/-9.1% versus -0.2+/-8.6%, P<0.05; change of end-systolic volume: -5.4+/-17.0 mL versus 6.5+/-21.9 mL, P<0.05). In OMI patients, however, there was no significant change of LVEF and ventricular remodeling in spite of significant improvement of coronary flow reserve after cell infusion. G-CSF-based cell therapy did not aggravate neointimal growth with DES implantation. CONCLUSIONS: Intracoronary infusion of mobilized PBSCs with G-CSF improves LVEF and remodeling in patients with AMI but is less definite in patients with OMI. G-CSF-based stem cell therapy with DES implantation is both feasible and safe, eliminating any potential for restenosis.

Acute Disease↗
PubMed2006

Integrin-linked kinase, a hypoxia-responsive molecule, controls postnatal vasculogenesis by recruitment of endothelial progenitor cells to ischemic tissue.

BACKGROUND: Recruitment and adhesion of endothelial progenitor cells (EPCs) to hypoxic endothelial cells (ECs) is essential for vasculogenesis in ischemic tissue; little is known, however, about the key signals or intracellular signaling pathways involved in orchestrating the expression of adhesion molecules by ECs in response to hypoxia and how this is related to the recruitment of EPCs to the ischemic tissue. Here, we report that endogenous integrin-linked kinase (ILK) is a novel molecule that responds to hypoxia in ECs that regulates the expression of stromal cell-derived factor-1 (SDF-1) and intercellular adhesion molecule-1 (ICAM-1) through nuclear factor-kappaB and hypoxia-inducible factor-1alpha and induces recruitment of EPCs to ischemic areas. METHODS AND RESULTS: Under hypoxia, both the endogenous amount and kinase activity of ILK were time-dependently upregulated in ECs, which was associated with increased ICAM-1 and SDF-1. This upregulation of ILK was mediated by stabilization of ILK by heat shock protein 90. ILK overexpression in normoxic ECs resulted in ICAM-1 and SDF-1 upregulation through dual control by nuclear factor-kappaB and hypoxia-inducible factor-1alpha. Blockade of ILK in hypoxic ECs significantly abrogated the expression of both molecules, which led to decreased EPC incorporation into ECs. A hindlimb ischemia model showed that ILK blockade significantly reduced EPC homing to ischemic limb and consequently led to poor neovascularization. Overexpression of ILK in the Matrigel plug significantly improved neovascularization in vivo, whereas the blockade of ILK resulted in the opposite effect. CONCLUSIONS: Endogenous ILK is a novel and physiological upstream responder of numerous intracellular molecules involved in hypoxic stress in ECs and may control the recruitment of EPCs to ischemic tissue.

Cell Adhesion↗
PubMed2006

The effect of stem cell mobilization by granulocyte-colony stimulating factor on neointimal hyperplasia and endothelial healing after vascular injury with bare-metal versus paclitaxel-eluting stents.

OBJECTIVES: The goal of this study was to investigate the effect of mobilized stem cells by granulocyte-colony stimulating factor (G-CSF) on neointimal growth, the biologic impact on vascular healing process, and the utility of paclitaxel-eluting stent (PES) in this circumstance. BACKGROUND: Questions have been raised on the safety of stem cell mobilization because of the tendency of neointimal overgrowth in a recent clinical trial, despite improvement of cardiac function. METHODS: Rabbits underwent iliac artery injury with bare-metal stent (BMS) or PES and then received rhG-CSF or placebo for 6 days. Morphometric analysis and scanning electron microscopy for re-endothelialization were performed. The characteristics of mobilized peripheral blood mononuclear cells were determined in vitro, and the fate of these cells was evaluated by re-infusion with tagging in vivo. RESULTS: At day 60 after stenting, neointimal overgrowth was observed at BMS with G-CSF. The tendency of neointimal overgrowth was substantially reduced on PES. Intriguingly, the delayed endothelial recovery on PES was restored to normal after G-CSF treatment. The G-CSF increased not only the endothelial progenitor cells, but also putative smooth muscle progenitor cells. Paclitaxel, at working concentration, preferentially inhibited proliferation of smooth muscle lineage cells rather than endothelial lineage cells. CONCLUSIONS: Our findings demonstrate that G-CSF mobilizes putative vascular progenitor cells in peripheral blood, which induces neointimal overgrowth at stented vasculature. Unique differential action of paclitaxel results in the enhanced endothelial healing with reduced neointimal growth after G-CSF treatment, suggesting that drug-eluting stents might be the optimal modality for revascularization in cytokine-based stem cell therapy.

Animals↗
PubMed2006

Increased risk of atherothrombotic events associated with cytochrome P450 3A5 polymorphism in patients taking clopidogrel.

BACKGROUND: Clopidogrel is a prodrug requiring metabolism by cytochrome P450 3A (CYP3A) isoenzymes, including CYP3A5, in order to be active. It is controversial whether clopidogrel interacts with CYP3A inhibitors. We investigated the influence of CYP3A5 polymorphism on the drug interaction of clopidogrel. METHODS: In phase 1 of the study, we administered clopidogrel to 16 healthy volunteers who had the CYP3A5 non-expressor genotype (*3 allele) and 16 who had the CYP3A5 expressor genotype (*1 allele) with and without pretreatment with itraconazole, a potent CYP3A inhibitor. A platelet aggregation test was performed at baseline, 4 hours, 24 hours and 6 days after clopidogrel administration. In phase 2, we compared clinical outcomes of 348 patients treated with clopidogrel after successful coronary angioplasty with bare-metal stent implantation according to their CYP3A5 genotype; the primary end point was a composite of atherothrombotic events (cardiovascular death, myocardial infarction and non-hemorrhagic stroke) within 1 and 6 months after stent implantation. RESULTS: In phase 1, the change in platelet aggregation after clopidogrel administration and pretreatment with itraconazole was greater among the subjects with the CYP3A5 expressor genotype than among those with the non-expressor genotype: 24.9% (standard deviation [SD] 13.9%) v. 6.2% (SD 13.5%) at 4 hours (p < 0.001); 27.7% (SD 16.5%) v. 2.5% (SD 8.3%) at 24 hours (p < 0.001); and 33.5% (SD 18.6%) v. 17.8% (SD 13.8%) at day 7 (p < 0.01). In phase 2, atherothrombotic events occurred more frequently within 6 months after stent implantation among the patients with the non-expressor genotype than among those with the expressor genotype (14/193 v. 3/155; p = 0.023). Multivariable analysis showed that the CYP3A5 polymorphism was a predictor of atherothrombotic events in clopidogrel users. INTERPRETATION: People with the CYP3A5 non-expressor genotype are vulnerable to drug interactions between clopidogrel and CYP3A inhibitors. This phenomenon may be associated with worse outcomes in patients with the non-expressor genotype who are given clopidogrel after coronary angioplasty and implantation of bare-metal stents.

Aged↗
PubMed2006

Intercellular adhesion molecule-1 is upregulated in ischemic muscle, which mediates trafficking of endothelial progenitor cells.

BACKGROUND: Trafficking of transplanted endothelial progenitor cells (EPCs) to an ischemic organ is a critical step in neovascularization. This study was performed to elucidate the molecular mechanism of EPC trafficking in terms of adhesion molecules. METHODS AND RESULTS: Using murine hindlimb ischemia model, we examined expressions of E-selectin, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and platelet-endothelial cell adhesion molecule-1 (PECAM-1) in ischemic muscle by immunofluorescence. ICAM-1 was overexpressed in ischemic muscle compared with nonischemic muscle, whereas expressions of E-selectin, VCAM-1, and PECAM-1 did not show that much difference. ICAM-1 was also upregulated by hypoxia in murine endothelial cells (ECs) as assessed by immunoblot and flow cytometry. EPCs were attached to ECs specifically through ICAM-1/beta-2 integrin interaction in vitro. When EPCs were labeled with fluorescent dye or radioisotope (Tc-99m-HMPAO) and systemically administrated in vivo, EPCs preferentially homed to ischemic muscle. By blocking ICAM-1, EPCs entrapment to ischemic limb in vivo was significantly reduced and neovascularization induced by EPC transplantation was attenuated. CONCLUSIONS: ICAM-1 is upregulated by ischemia, and this is closely associated with EPCs entrapment to ischemic limb. Our findings suggest that ICAM-1 expression might be important in regulating the process of neovascularization through its ability to recruit EPCs.

Animals↗
PubMed2006

Common adrenergic receptor polymorphisms as novel risk factors for vasospastic angina.

BACKGROUND: Sympathetic activity mediated by adrenergic receptors (ARs) appears to play an important role in controlling the vasomotor tone and, thus, may be associated with vasospastic angina (VA). We investigated the association of the common functional polymorphisms of the AR gene and VA. The candidates were alpha2CDel322-325, beta1Gly389Arg, beta2Arg16Gly, and beta2Gln27Glu polymorphisms. METHODS: Eighty-two patients with VA, confirmed by coronary angiography with or without ergonovine provocation test, and 114 apparently healthy control subjects were investigated for genotype of 4 AR polymorphisms and established risk factors of ischemic heart disease. RESULTS: The minor alleles were alpha2CDel322-325, beta1Gly389, beta2Gly16, and beta2Glu27 and their frequencies were 7%, 18%, 42%, and 29%, respectively, in the control subjects of this Korean population, which were different from those of other ethnic groups. On univariate analysis, age, smoking, male sex, alpha2CDel322-325 allele carrier state, and beta2Gln27 homozygote state were significant risk factors for VA. After multivariate analysis using multiple logistic regression model, age (odds ratio [OR] 1.809, CI 1.046-1.135, P < .0001), smoking (OR 4.902, CI 2.105-11.416, P = .0002), alpha2CDel322-325 allele carrier state (OR 5.132, CI 2.094-12.578, P = .0003), and beta2Gln27 allele homozygosity (OR 3.152, CI 1.364-7.285, P = .0072) remained as independent risk factors. In the combined genotype analysis, the effect of beta2Gln27 allele was evident only when the alpha2CDel322-325 allele was absent. CONCLUSIONS: The alpha2CDel322-325 allele carrier state and beta2Gln27 allele homozygote state were identified as novel risk factors of VA in this Korean population. This result suggests the importance of the adrenergic stimuli and the genetic background in the pathogenesis of the VA.

Adult↗
PubMed2005

Beta-catenin overexpression augments angiogenesis and skeletal muscle regeneration through dual mechanism of vascular endothelial growth factor-mediated endothelial cell proliferation and progenitor cell mobilization.

OBJECTIVE: Beta-catenin plays a critical role in directing cell fate during embryogenesis, and uncontrollable activation leads to cancers, suggesting its importance in cell survival and proliferation. However, little is known regarding its role in endothelial cell (EC) and skeletal muscle proliferation and progenitor cell mobilization. METHODS AND RESULTS: Beta-catenin enhanced ECs proliferation, protected ECs from apoptosis, and increased the capillary forming capabilities, which was completely blocked by inhibition of its nuclear translocation. In addition, the increased proliferation by beta-catenin was associated with increased expression of cyclin E2. In skeletal myocytes, beta-catenin overexpression increased proliferation with cyclin D1 expression, decreased apoptosis, and induced hypertrophy. Furthermore, beta-catenin induced the expression of vascular endothelial growth factor (VEGF) in skeletal myocytes, resulting in EC proliferation. In a mouse hindlimb ischemia model, beta-catenin significantly increased recovery of blood perfusion, capillary density along with enhanced VEGF expression, and the number of proliferating ECs and myocytes. Local delivery of beta-catenin also promoted angiogenic progenitor cell mobilization and increased the number of satellite cells. CONCLUSIONS: Beta-catenin may be an important modulator of angiogenesis and myocyte regeneration not only by directly enhancing proliferation and survival of ECs and skeletal myocytes but also by inducing VEGF expression and promoting angiogenic progenitor cell mobilization and muscle progenitor cell activation.

Animals↗
PubMed2005

Synergistic neovascularization by mixed transplantation of early endothelial progenitor cells and late outgrowth endothelial cells: the role of angiogenic cytokines and matrix metalloproteinases.

BACKGROUND: Two types of cells are cultured from the human peripheral blood, early endothelial progenitor cells (EPCs) and outgrowth endothelial cells (OECs), as previously reported. Here, we further characterize these cells, especially with respect to their different origins and functions both in vitro and in vivo. We also investigated whether the combination of these different cell types shows synergism during neovascularization. METHODS AND RESULTS: Early EPCs were heterogeneously made up of both CD14+ monocyte-derived cells, which secrete cytokines, and CD14(-)-derived cells, which contain high levels of (CD34+)KDR+ cells. OECs were cultured almost exclusively from CD14- cells, not CD14+ cells, and were distinct from mature endothelial cells in terms of proliferation potential, KDR+ expression level, and telomerase activity. A portion of cells from CD14- cells and early EPCs produced rapidly proliferating, capillary-forming cells in both the Matrigel plug and the ischemic hind limb similar to OECs. Early EPCs and OECs expressed receptors for vascular endothelial growth factor and interleukin-8, cytokines secreted by early EPCs. There was a differential increase in matrix metalloproteinases (MMPs): MMP-9 in early EPCs and MMP-2 in OECs. In vitro, the angiogenic capability of the 2 cell types was augmented by mutual interaction through cytokines and MMPs. Injection of a mixture of the 2 cells resulted in superior neovascularization in vivo to any single-cell-type transplantation. CONCLUSIONS: Distinct origins of the different types of EPCs exist that have different functions in neovascularization. Mixed transplantation of these cells results in synergistic neovascularization through cytokines and MMPs.

Animals↗
PubMed2005

Regulation of endothelial cell and endothelial progenitor cell survival and vasculogenesis by integrin-linked kinase.

OBJECTIVE: New vessel formation is a dynamic process of attachment, detachment, and reattachment of endothelial cells (ECs) and endothelial progenitor cells (EPCs) with each other and with the extracellular matrix (ECM). Integrin-linked kinase (ILK) plays a pivotal role in ECM-mediated signaling. Therefore, we investigated the role of ILK in ECs and EPCs during neovascularization. METHODS AND RESULTS: In human umbilical cord vein ECs and EPCs, endogenous ILK expression, along with subsequent cell survival signals phospho-Akt and phospho-glycogen synthase kinase 3beta, was reduced after anchorage or nutrient deprivation. Even brief anchorage deprivation resulted in retarded capillary tube formation by ECs. Adenoviral ILK gene transfer in ECs and EPCs reversed the decrease in cell survival signals after anchorage or nutrient deprivation, leading to enhanced survival, reduced apoptosis, and significantly accelerated the functional recovery after reattachment. And ILK overexpressing EPCs significantly improved blood flow recovery and prevented limb loss in nude mice hindlimb ischemia model. Furthermore, the efficacy of systemic delivery was equivalent to local injection of ILK-EPCs. CONCLUSIONS: ILK overexpression protects ECs and EPCs from anchorage- or nutrient-deprived stress and enhances neovascularization, suggesting that ILK is an optimal target gene for genetically modified cell-based therapy. Neovascularization is a dynamic process of detachment and reattachment of ECs and EPCs. Endogenous ILK expression was decreased in various stress conditions, and the gene transfer of ILK protected ECs and EPCs from temporary anchorage or nutrient deprivation. Furthermore, ILK gene transfer in EPCs significantly enhanced neovascularization in vivo.

Animals↗
PubMed2005

The association between the T102C polymorphism of the HTR2A serotonin receptor gene and HDL cholesterol level in Koreans.

5-HT2A is one of major serotonin receptor that is involved in the action of serotonin-targeting drugs. Previous clinical studies have shown an unexpected association between lower cholesterol level and psychiatric diseases, in which T102C polymorphism of HTR2A, gene of 5-HT2A serotonin receptor, might be involved. Therefore, we hypothesized a potential association between lower cholesterol level and T102C polymorphism. The effect of the T102C polymorphism on the serum lipid profiles of 646 subjects without specific psychiatric disease was investigated. Genotype was determined by polymerase chain reaction and restriction fragment length polymorphism analysis. There were significantly lower levels of total cholesterol (193.6 +/- 35.0 versus 202.1 +/- 45.5 mg/dl, p = 0.016) and HDL-cholesterol (42.7 +/- 11.6 versus 46.3 +/- 12.7 mg/dl, p = 0.004) in CC genotype than non-CC genotypes. Moreover, multivariate analysis showed that the CC genotype is a strong predictor of a lower HDL-cholesterol level (p < 0.001). In conclusion, this study shows that the CC genotype of the HTR2A gene is related to lower HDL-cholesterol level in Koreans. This is the first demonstration showing the potential genetic relationship between the serotonin receptor gene polymorphism and the HDL-cholesterol level.

Case-Control Studies↗
PubMed2005

NF-kappaB decoy potentiates the effects of radiation on vascular smooth muscle cells by enhancing apoptosis.

NF-kappaB promotes cell survival against external stress such as radiation. We examined whether NF-kappaB decoy transfection enhances the antiproliferative effects of radiation on vascular smooth muscle cells (VSMCs) in vitro. The irradiation induced activation or nuclear translocation of NF-kappaB p65 in VSMCs was confirmed by immunofluorescence. NF-kappaB decoy transfection resulted in inhibition of the radiation-induced NF-kappaB activation in VSMCs and the subsequent reduction of transcription and translocation of ICAM, iNOS, and TNF-alpha, downstream molecules under the control of NF-kappaB. By using MTT assay, NF-kappaB decoy augmented the antiproliferative effects of radiation, where the effect of low dose radiation (2 and 8-Gy) of the cells transfected with NF-kappaB decoy was equivalent to the high dose (16-Gy) irradiated non-transfected cells at 48 h after irradiation: 1.06+/-0.16, 1.11+/-0.22, 1.20+/-0.25, respectively. The decrease in proliferation and survival of the radiation treated cells by flow cytometry analysis showed that NF-kappaB inhibition did not show any additive effects on the cell cycle of the irradiated VSMCs, while apoptosis was significantly increased after NF-kappaB decoy transfection in the irradiated VSMCs (apoptosis fraction: 13.33+/-2.08% vs. 26.29+/-7.43%, for radiation only vs. radiation+NF-kappaB decoy transfection, P < 0.05). In addition, at 48 h, NF-kappaB decoy transfection dose dependently (10 microM vs. 20 microM) inhibited proliferation of 16Gy-irradiated VSMCs, and showed greater antiproliferative efficacy than 100 microM sulfasalazine, a specific NF-kappaB inhibitor. These results indicate that NF-kappaB inhibition reduces proliferation and survival of irradiated VSMCs, likely by increased apoptosis rather than additive cell cycle arrest and suggest the possibility of adjunctive gene therapy using NF-kappaB decoy to improve efficacy and to decrease the adverse effects of intracoronary radiation therapy.

Animals↗
PubMed2005

Activated forkhead transcription factor inhibits neointimal hyperplasia after angioplasty through induction of p27.

OBJECTIVE: We examined the effects of FKHRL1 (forkhead transcription factor in rhabdomyosarcoma like-1) overexpression on vascular smooth muscle cell (VSMC) proliferation, apoptosis, and cell cycle, in vitro, and the role of FKHRL1 and p27 in the pathophysiology of neointimal growth after balloon angioplasty, in vivo. Furthermore, we tested whether FKHRL1 overexpression can inhibit neointimal hyperplasia in a rat carotid artery model. METHODS AND RESULTS: Adenovirus expressing the constitutively active FKHRL1 (FKHRL1-TM; triple mutant) with 3 Akt phosphorylation sites mutated was transfected to subconfluent VSMCs. FKHRL1 overexpression in cultured VSMCs increased p27 expression, leading to G1 phase cell-cycle arrest and increased apoptosis. In vivo, the phosphorylation of FKHRL1 increased significantly 3 hours after balloon injury and decreased thereafter, with the subsequent downregulation of p27. Although the phosphorylation of FKHRL1 was greatest at 3 hours, the downregulation of p27 showed a temporal delay, only slightly starting to decrease after 3 hours and reaching a nadir at 72 hours after balloon injury. Gene transfer of FKHRL1-TM increased p27, decreased proliferation, and increased apoptosis of VSMCs, which resulted in a marked reduction in neointima formation (intima-to-media ratio: 0.31+/-0.13 versus 1.17+/-0.28, for FKHRL1-TM versus Adv-GFP; P<0.001). CONCLUSIONS: Balloon angioplasty leads to the phosphorylation of FKHRL1 and decreased expression of p27, thereby promoting a proliferative phenotype in VSMCs in vitro and in vivo. This study reveals the importance of FKHRL1 in proliferation and viability of VSMCs and suggests that it may serve as a molecular target for interventions to reduce neointima formation after angioplasty.

Angioplasty, Balloon↗
PubMed2005

Novel index of coronary collateral development as a useful predictor of clinical outcome in type 2 diabetic patients with coronary artery disease.

BACKGROUND: There is a paucity of information regarding the impact of the coronary collaterals on prognosis in type 2 diabetic (T2DM) patients. We developed a novel index, which considers not only the degree of collateral circulation but also the stimulus of collateral development, and investigated its prognostic value in T2DM patients with coronary artery disease (CAD). METHODS AND RESULTS: One hundred and ninety four consecutive T2DM patients were analyzed and followed for an average of 30 months. We measured the diameter stenosis (DS; %), corrected TIMI frame count (CTFC) and Rentrop score at 3 major epicardial coronary arteries. The collateral development (CD) score was calculated by: (Sigma Rentrop score +1)/Sigma [DS (%) x CTFC] x1,000. During the follow-up, acute cardiovascular events occurred in 49 patients. By multivariate analysis, the CD score was an independent predictor of adverse events not only in the total population (p<0.001), but in all 3 subgroups (p=0.020 for coronary artery bypass grafting, p=0.030 for percutaneous transluminal coronary angioplasty (PTCA) and p=0.003 for the medical group). Furthermore, patients in the tertile with the highest CD score showed improved survival by Kaplan-Meier analysis in the total population, the PTCA and the medical group. CONCLUSIONS: The CD score, a novel index of collateral development, may be a useful predictor of clinical outcome in T2DM patients with CAD.

Aged↗
PubMed2004

Celecoxib, a cyclooxygenase-2 inhibitor, reduces neointimal hyperplasia through inhibition of Akt signaling.

BACKGROUND: Celecoxib has been shown to have antitumor effects that may be mediated through the cyclooxygenase-independent inhibition of Akt signaling. Here, we examined the effects of celecoxib on neointimal formation after balloon injury and its mechanism of action. METHODS AND RESULTS: In vitro experiments were performed to evaluate the effects of celecoxib on the Akt/GSK signaling axis and the viability of rat vascular smooth muscle cells (VSMCs). In vivo experiments examined the effects of celecoxib, aspirin, and vehicle on neointimal growth after denudation injury to rat carotid arteries. In vitro, celecoxib suppressed the phosphorylation of Akt and GSK in cultured VSMCs, leading to a reduction in viable cell number, which was reversed by transduction of constitutively active Akt. Such a reduction in cell number was mediated by inhibition of proliferation and induction of apoptosis. In vivo, celecoxib reduced injury-induced phosphorylation of Akt and GSK, reduced VSMC proliferation, and increased caspase-3 activation and VSMC apoptosis at 3 days after injury, whereas aspirin had no effect. At 2 weeks after injury, celecoxib reduced intima-to-media ratio, whereas aspirin had no effect. Adenovirus-mediated delivery of dominant negative Akt was as effective as celecoxib at inhibiting neointimal formation. Conversely, gene delivery of constitutively active Akt significantly reversed the inhibition of intimal hyperplasia by celecoxib, providing causal evidence that the modulation of Akt signaling by celecoxib is a physiologically relevant mechanism. CONCLUSIONS: Celecoxib is a potential inhibitor of neointimal formation by blocking injury-induced Akt activation. These findings suggest a potential use for celecoxib in the prevention of restenosis after angioplasty.

Animals↗
PubMed2004

Effects of intracoronary infusion of peripheral blood stem-cells mobilised with granulocyte-colony stimulating factor on left ventricular systolic function and restenosis after coronary stenting in myocardial infarction: the MAGIC cell randomised clinical trial.

BACKGROUND: Bone-marrow stem-cell transplantation has been shown to improve cardiac function in patients with myocardial infarction. We examined the feasibility and efficacy of granulocyte-colony stimulating factor (G-CSF) therapy and subsequent intracoronary infusion of collected peripheral blood stem-cells (PBSCs) in such patients. METHODS: We prospectively randomised 27 patients with myocardial infarction who underwent coronary stenting for the culprit lesion of infarction into three groups; cell infusion (n=10), G-CSF alone (n=10), and control group (n=7). Changes in left ventricular systolic function and perfusion were assessed after 6 months. By December, 2003, seven patients from the cell infusion group, three from the G-CSF group, and one from the control group had been assessed. FINDINGS: G-CSF injection and intracoronary infusion of the mobilised PBSC did not aggravate inflammation and ischaemia during the periprocedural period. Exercise capacity (mean treadmill exercise time: 450 s [SD 178] at baseline vs 578 s [168] at 6 months' follow-up, p=0.004), myocardial perfusion (perfusion defect 11.6% [9.6] vs 5.3% [5.0], p=0.020) and systolic function (left ventricular ejection fraction 48.7% [8.3] vs 55.1% [7.4], p=0.005) improved significantly in patients who received cell infusion. However, we noted an unexpectedly high rate of in-stent restenosis at culprit lesion in patients who received G-CSF, and therefore we stopped enrollment. INTERPRETATION: G-CSF therapy with intracoronary infusion of PBSC showed improved cardiac function, and promoted angiogenesis in patients with myocardial infarction. However, aggravation of restenosis could be a serious problem. In future studies with G-CSF based stem-cell therapy, patients should be carefully monitored for unexpected effects.

Arteries↗
PubMed2004

Thalidomide as a potent inhibitor of neointimal hyperplasia after balloon injury in rat carotid artery.

OBJECTIVE: Inflammation is one of the main pathogeneses of neointimal hyperplasia after coronary intervention. Thalidomide, because of its potent antiinflammatory and immunomodulatory properties, is being re-evaluated in several clinical fields. Therefore, we examined whether thalidomide therapy affects neointimal formation. METHODS AND RESULTS: In male Sprague-Dawley rats, 100 mg/kg of either thalidomide or sucrose (control) was administered daily from 3 days before injury to 2 weeks after conventional carotid artery denudation injury. Thalidomide administration resulted in a significant reduction of neointimal formation (neointima to media ratio 1.26+/-0.29 versus 0.35+/-0.13, P<0.001) and proliferative activity of vascular smooth muscle cells. In addition, arterial macrophage infiltration and local expressions of tumor necrosis factor alpha (TNF-alpha) and basic fibroblast growth factor (bFGF) in the injured arteries as measured by immunohistochemistry and immunoblot analysis were significantly reduced by thalidomide treatment. Serum TNF-alpha, measured by ELISA, was also significantly reduced in the thalidomide-treated animals compared with controls after injury (856+/-213 versus 449+/-68 pg/mL on day 3, P=0.001; 129+/-34 versus 63+/-18 pg/mL on day 14, P=0.001), and we observed a good positive correlation between the serum TNF-alpha levels and the severity of neointimal growth. CONCLUSIONS: We found that thalidomide, through its antiinflammatory and antiproliferative effects, significantly inhibits neointimal hyperplasia in balloon-injured rat carotid arteries. Our results suggest a potential role of thalidomide as a potent inhibitor of neointimal formation after angioplasty.

Animals↗