Asialoerythropoietin exerts stronger angiogenic activity than erythropoietin via its binding affinity to tissue.

PURPOSE: Although erythropoietin (EPO) is known to express angiogenic and cardioprotective effects, it also induces hypertension, polycythemia, and platelet activation, which may cause serious adverse effects in patients with cardiovascular diseases. We compared the angiogenic effects of EPO and its nonerythropoietic derivative, asialo-EPO (AEPO). METHODS: Lower limb ischemia was induced in ICR and C57/BL mice. Mice were injected intramuscularly with 2 µg/kg of EPO derivatives for 6 or 7 days. To assess biological differences, the tissue affinity of both EPO derivatives was analyzed in vitro using heparin affinity column chromatography. Tissue affinity was also analyzed in vivo using an intramuscular pharmacokinetic study. RESULTS: The survival of ischemic legs was better in the AEPO group than that in the EPO group (5/13 = 38.5 % vs 1/13 = 7.7 %, p < 0.05), and an increase in regenerated vessels was observed in the AEPO group, but not in the EPO group in ICR mice. Vessel/muscle ratios in control, EPO, and AEPO groups were 0.50 ± 0.34, 0.61 ± 0.32, and 2.83 ± 1.13, respectively (p < 0.0001). On the other hand, regenerated vessels were observed in both EPO and AEPO groups (p < 0.001) in C57/BL mice. AEPO, but not EPO, expressed heparin affinity in vitro. Intramuscularly injected EPO gradually decreased in muscle tissue, while AEPO was maintained at 2.5 ng/muscle for 1 day after several hours of a rapid clearance phase in vivo. CONCLUSIONS: AEPO exerts stronger angiogenic effects than those of EPO presumably via its tissue affinity. Administration of AEPO is a promising option for the treatment of patients with critical limb ischemia.

Imatinib mesilate inhibits neointimal hyperplasia via growth inhibition of vascular smooth muscle cells in a rat model of balloon injury.

Restenosis is a major problem in percutaneous catheter intervention (PCI) for coronary artery stenosis in patients with acute myocardial infarction. Coronary restenosis arises from intimal hyperplasia, i.e., hyperplasia of the vascular smooth muscle cells (SMCs) caused by endothelial cell (EC) damage due to PCI. Drug eluting stent (DES), a novel stent coated with a cell-growth inhibitor, such as rapamycin, has been utilized to block SMC proliferation, but DES also blocks EC repair and thus requires the administration of anti-platelets for a long time to prevent thrombus formation after PCI. Moreover, insufficient prevention of platelet aggregation sometimes induces restenosis after PCI. One of the signal transduction inhibitors, imatinib mesilate, blocks tyrosine kinase activity of platelet-derived growth factor receptor (PDGFR), and therefore it may block the development of neointima through growth inhibition of SMCs without the obstructive effect on EC-repair. We therefore studied the effects of imatinib on neointimal hyperplasia in a balloon injury model of rat carotid arteries. Rats were orally administered with imatinib for 14 days after balloon injury, and sacrificed to analyze the neointimal formation. Intimal hyperplasia was inhibited by imatinib in a dose-dependent manner. Therefore imatinib presumably obstructed the growth of SMCs via interception on growth-signaling of PDGFR. The administration of imatinib after coronary stenting or the use of an imatinib-eluting stent may further reduce the risk of restenosis in patients.

Lung resection combined with percutaneous coronary intervention using cypher stents: a case report.

Treatment of concomitant severe coronary artery disease and lung cancer is a complicated issue. The present study describes a case of a 65-year-old man with coronary artery disease and primary lung cancer that was successfully treated with lung resection and percutaneous coronary intervention (PCI) using Cypher stents. Prior to lung resection, the patient underwent a PCI for diffuse stenosis of the right coronary artery and the circumflex artery. Cypher stents were deployed for both lesions. Five days after stent implantation, a right lower lobectomy was performed successfully. To the best of our knowledge, this is the first report of lung resection and PCI using Cypher stents.

Marked decrease of plasma VEGF after implantation of autologous bone marrow mononuclear cells in a patient with critical limb ischemia--a case report.

The authors performed autologous bone marrow mononuclear cells implantation (BMI) in a 79-year-old man with critical limb ischemia. After BMI, the resting pain of the ischemic leg improved gradually. They measured the plasma concentrations of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and serum hepatocyte growth factor (HGF) in the blood from bilateral femoral veins. Before BMI, the plasma VEGF and bFGF concentrations were much greater in the ischemic leg than in the other lower limb, but decreased to the same concentrations as those in the contralateral lower extremity after BMI. The large concentrations of the angiogenic factors VEGF and bFGF in plasma indicate the severity and extent of the leg ischemia. BMI resulted in lower levels of VEGF and bFGF, and this fall is the hallmark of the effectiveness of BMI in the treatment of peripheral artery disease.

Expression of coxsackievirus and adenovirus receptor in neointima of the rat carotid artery.

Our previous study revealed that the coxsackievirus and adenovirus receptor (CAR) is a homophilic cell adhesion molecule and may function as a sensor of cell-cell interactions in the brain and damaged heart. In this study, we investigated if CAR expression is involved in the formation of neointimal hyperplasia using a balloon injury model of rat carotid artery. Cultured vascular smooth muscle cells (SMCs) from rat aorta were also studied. CAR antigen was constitutively detected in the endothelial cells (ECs) but not in SMCs before injury. On Day 5 after balloon injury, CAR was expressed strongly in the first layer of medial SMCs. Neointimal hyperplasia was observed on Day 7, and strong expressions of CAR concomitantly with proliferating cell nuclear antigen (PCNA) were obvious in the neointimal SMCs, while CAR in medial SMCs disappeared. The expression of CAR mRNA reached a peak on Day 7 and declined gradually to the basal levels. When the ECs regenerated on Day 14, CAR antigen was observed in the ECs but disappeared in the neointima. CAR together with PCNA was expressed abundantly in the proliferating SMCs in vitro and diminished in cells grown to a confluent state. The abundant expression of CAR in the neointima may facilitate an adenoviral gene therapy.

Angiopoietin-1, angiopoietin-2 and tie-2 in the coronary circulation of patients with and without coronary collateral vessels.

BACKGROUND: The role of the angiopoietin (Ang)/Tie-2 system in coronary collateral growth is not well understood, so the purpose of this study was to investigate and elucidate the relationship of this system to coronary collateral formation in patients with coronary artery disease (CAD). METHODS AND RESULTS: Fifty-nine patients with CAD were recruited. Blood samples from the left ventricle (LV) and coronary sinus (CS) were obtained during cardiac catheterization, and serum concentrations of Ang-1, Ang-2, and Tie-2 were measured by enzyme-linked immunosorbent assay. Patients were then classified as mild CAD (n=30), defined as

Erythroid cells play essential roles in angiogenesis by bone marrow cell implantation.

Bone marrow cell implantation (BMI) has been utilized to treat patients with limb and heart ischemia. BMI provides angiogenic precursors and angiogenic cytokine-producing cells, especially erythroid cells. In this study, we induced in vitro angiogenesis cultures and in vivo BMI simulation using a murine limb ischemia model to examine the role of erythroid cells and the effect of erythropoietin (EPO). Human erythroid colonies (BFU-e) induced capillary networks around the colonies in vitro. Erythroid cells in human bone marrow produced vascular endothelial growth factor and placental growth factor. The angiogenic effects of erythroid cells were further amplified in the presence of EPO. Limb-ischemic mice were treated with BMI +/- EPO, and limb survival, blood flow recovery, and muscle histology were analyzed. Treatment with whole bone marrow cells + EPO significantly improved limb survival and blood flow. The cumulative effects of EPO on BMI induced and increase in capillary number and artery enlargement. Erythroid cells were essential for the in vivo effects of BMI, and CD14-positive cells supported the biological effects. In addition to the direct effect of EPO on angiogenesis, EPO showed indirect effect on angiogenesis through amplifying the angiogenic effects by erythroid cells supported by CD14-positive cells.

Relationship between serum lipoprotein(a) concentrations and coronary vasomotion in coronary spastic angina.

BACKGROUND: Elevated lipoprotein(a) (Lp(a)) concentrations are reported to impair endothelium-dependent vasodilatation of the epicardial coronary artery. However, the effects on vasomotor abnormalities in coronary spastic angina (CSA) have not been thoroughly investigated. METHODS AND RESULTS: In the present study 80 sites of spasm (spastic sites) without significant organic stenosis (% diameter stenosis <50%) were assessed in 80 patients with CSA diagnosed by intracoronary ergonovine (EM) test. Spastic sites were divided into 2 groups: Group 1 included 30 sites provoked by the full dose (=50 microg) of EM, and Group 2 included 50 sites provoked with less than 50 microg (34.7+/-8.2 microg). Control subjects (n=22) did not show coronary spasm with the EM test. Serum Lp(a) concentrations were measured in all patients. Group 2 had a significantly greater basal coronary artery tone in the spastic sites than Group 1 (p<0.001). Lp(a) level in Group 2 was significantly higher compared with both the control group and Group 1 (p<0.05 by analysis of variance). Multivariate analysis confirmed that only serum Lp(a) concentration was associated with low-dose EM spasm provocation. CONCLUSIONS: Serum Lp(a) concentration could be a marker for high disease activity in CSA.

Clinical application of bone marrow implantation in patients with arteriosclerosis obliterans, and the association between efficacy and the number of implanted bone marrow cells.

BACKGROUND: There have been a number of recent reports on the use of autologous bone marrow implantation (BMI) in the treatment of peripheral arterial disease, with a clinical response rate of approximately 70%. However, the factors that influence efficacy have not yet been clarified. We have analyzed the relationship between the number of implanted bone marrow cells and the clinical efficacy of BMI. METHODS AND RESULTS: Eight patients with arteriosclerosis obliterans were treated with BMI. Bone marrow was aspirated from the ilium (500-1,000 ml), the mononuclear cells were separated and then were implanted. The clinical effectiveness of BMI was evaluated by assessing changes in the ankle-brachial pressure index (ABI) and the transcutaneous oxygen pressure (TcO2) between the pre-treatment baseline, with follow-up testing at 4 weeks. These changes were defined as DeltaABI and DeltaTcO2. The mean number of CD34-positive cells was 1.04+/-0.60 x10(6) /kg body weight. There was a strong correlation between the number of CD34-positive cells and DeltaABI (r=0.754, p=0.028). CONCLUSIONS: It is likely that the number of implanted CD34-positive cells is one of the primary factors that influence the clinical efficacy of BMI.

Analysis of postextrasystolic relaxation response in the human heart.

Postextrasystolic potentiation is the phenomenon in which ventricular contractile force is strengthened by a preceding premature beat. However, the response of diastolic function after an extrasystole is unknown. We studied 58 patients with chronic heart failure (CHF) and two control subjects to evaluate the response of relaxation following extrasystole. At cardiac catheterization, from the derivative of the left ventricular (LV) pressure, the ratio of LV peak negative dP/dt (-dP/dt) of a postextrasystole to a basal beat was calculated and defined as the postextrasystolic relaxation response (PRR). PRR was compared with parameters of left ventriculography: LV end-diastolic volume index (EDVI), LV end-systolic volume index (ESVI), and LV ejection fraction (EF). The PRRs of the two control subjects were 0.80 and 0.84. The mean PRR of the CHF patients was 0.99 +/- 0.15. In all subjects, including patients and controls, correlation analysis between (EDVI, ESVI, and EF) and PRR yielded the following: (a) EDVI vs. PRR: R = 0.273, p = 0.036; (b) ESVI vs. PRR: R = 0.446, p < 0.001; and (c) EF vs. PRR: R = -0.520, p < 0.001. Thus, normal or non-failing human hearts showed a decline of -dP/dt in postextrasystole compared with the basal beats, but failing hearts had potentiated relaxation following an extrasystole.

Plasma concentrations of cytokines and neurohumoral factors in a case of fulminant myocarditis successfully treated with intravenous immunoglobulin and percutaneous cardiopulmonary support.

A 53-year-old Japanese man with fulminant myocarditis was referred. Percutaneous cardiopulmonary support (PCPS) was introduced immediately and intravenous immunoglobulin (IVIG) therapy followed for 2 days. Cardiac function showed signs of recovery on the 4th hospital day and the patient was weaned from PCPS on the 7th hospital day. Creatine kinase-MB peaked at 12 h after admission and was 176 ng/ml. Endomyocardial biopsy showed active myocarditis. A marked increase of the neutralizing antibody titer suggested coxsackievirus B3 infection. Plasma concentrations of cytokines and neurohumoral factors were analyzed. Proinflammatory cytokines, such as interleukin (IL)-1beta, IL-6 and tumor necrosis factor (TNF-alpha), and anti-inflammatory cytokines, such as IL-1 receptor antagonist, soluble TNF receptor-1 and IL-10, were elevated on admission and all had decreased on the 7th hospital day. Brain natriuretic peptide and noradrenaline were already elevated upon admission (1,940 pg/ml and 4.6 ng/ml, respectively) and decreased thereafter. Although IVIG therapy under PCPS is a common treatment for fulminant myocarditis, the immunological response in vivo remains unclear. This case demonstrated suppression of serum cytokines after IVIG and PCPS treatment. Immunological parameters in those who have been treated with IVIG and PCPS and survived without complications are of great value for evaluation of the therapy. Further analysis with more cases in a multicenter study is necessary.