Ex vivo expanded EPCs incorporate into foci of myocardial neovascularization and have a favorable impact on the preservation of left ventricular function.

Background-We investigated whether catheter-based, intramyocardial transplantation of autologous endothelial progenitor cells can enhance neovascularization in myocardial ischemia. Methods and Results-Myocardial ischemia was induced by placement of an ameroid constrictor around swine left circumflex artery. Four weeks after constrictor placement, CD31ϩ mononuclear cells (MNCs) were freshly isolated from the peripheral blood of each animal. After overnight incubation of CD31ϩ MNCs in noncoated plates, nonadhesive cells (NA/CD31ϩ MNCs) were harvested as the endothelial progenitor cell-enriched fraction. Nonadhesive CD31Ϫ cells (NA/CD31Ϫ MNCs) were also prepared. Autologous transplantation of 10 7 NA/CD31ϩ MNCs, 10

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Background-Diabetic cardiomyopathy (DCM) is characterized by microvascular pathology and interstitial fibrosis, which leads to progressive heart failure; however, the pathogenesis of DCM remains uncertain. Methods and Results-Using the streptozotocin-induced diabetic rat model, we evaluated the natural course of DCM over a period of 1 year by serial echocardiography, Western blot analysis for vascular endothelial growth factor (VEGF), endothelial progenitor cell assays, myocardial blood flow measurements, and histopathologic analysis that included terminal dUTP nick end-labeling (TUNEL), capillary and cardiomyocyte density, and fibrosis area. Downregulation of myocardial VEGF expression preceded all other features of DCM and was followed by increased apoptosis of endothelial cells, decreased numbers of circulating endothelial progenitor cells, decreased capillary density, and impaired myocardial perfusion. Apoptosis and necrosis of cardiomyocytes ensued, along with fibrosis and progressive diastolic and then systolic dysfunction. To provide further evidence of the central role of VEGF in the pathophysiology of DCM, we replenished myocardial VEGF expression using naked DNA gene therapy via direct intramyocardial injection of plasmid DNA encoding VEGF (phVEGF 165 ). VEGF-replenished rats showed increased capillary density, decreased endothelial cell and cardiomyocyte apoptosis, and in situ differentiation of bone marrow-derived endothelial progenitor cells into endothelial cells. These anatomic findings were accompanied by significant improvements in cardiac function. Conclusions-These

Endothelial progenitor cells (EPCs) have been isolated from circulating mononuclear cells in peripheral blood and shown to incorporate into foci of neovascularization, consistent with postnatal vasculogenesis. These circulating EPCs are derived from bone marrow and are mobilized endogenously in response to tissue ischemia or exogenously by cytokine stimulation. We show here, using a chemotaxis assay of bone marrow mononuclear cells in vitro and EPC culture assay of peripheral blood from simvastatin-treated animals in vivo, that the HMG-CoA reductase inhibitor, simvastatin, augments the circulating population of EPCs. Direct evidence that this increased pool of circulating EPCs originates from bone marrow and may enhance neovascularization was demonstrated in simvastatin-treated mice transplanted with bone marrow from transgenic donors expressing beta-galactosidase transcriptionally regulated by the endothelial cell-specific Tie-2 promoter. The role of Akt signaling in mediating effects of statin on EPCs is suggested by the observation that simvastatin rapidly activates Akt protein kinase in EPCs, enhancing proliferative and migratory activities and cell survival. Furthermore, dominant negative Akt overexpression leads to functional blocking of EPC bioactivity. These findings establish that augmented mobilization of bone marrow-derived EPCs through stimulation of the Akt signaling pathway constitutes a novel function for HMG-CoA reductase inhibitors.

Structural analysis of three libraries of up to five generations of self-assembling dendrons based on AB(3), AB(2), and combinations of AB(3) with AB(2) building blocks (Percec et al. J. Am. Chem. Soc. 2001, 123, 1302) facilitated the discovery of several nanoscale lattices previously unknown for organic compounds (3-D Pm3n cubic, 3-D P4(2)/mnm tetragonal, and a crystallographically forbidden 12-fold symmetry liquid quasicrystal) and provided fundamental correlations between the molecular structure of the dendron and the shape and the diameter of the supramolecular dendrimers which, in these experiments, were limited to less than 75 A. That study concluded that alternative design principles should be elaborated for the assembly of supramolecular dendrimers of larger dimensions. Here we report design principles, synthesis and analysis of first and higher generations AB(3) and AB(2) self-assembling dendrons, based on various primary structures, and combinations of (AB)(y)-AB(3) and (AB)(y)-AB(2) (i.e., from nondendritic AB where y = 1 to 11 and dendritic AB(3) and AB(2)) building blocks that produced the largest structural (including six new lattices) and dimensional (100 to 217 A diameter) diversity of supramolecular dendrimers.

In oesophageal squamous cell carcinoma vascular endothelial growth factor is associated with p53 mutation, advanced stage and poor prognosis S Uchida, Y Shimada, G Summary Vascular endothelial growth factor (VEGF) affects malignant tumours by promoting angiogenesis. The tumour-suppressor gene p53 has been thought to regulate VEGF. We investigated the effect of VEGF on oesophageal carcinoma and the connection between VEGF and p53. One hundred and nine resected oesophageal squamous cell carcinomas were examined. VEGF expression was analysed by immunohistochemical staining. Sixty-five tumours (59.6%, 65 out of 109) were classified as VEGF positive. A significant correlation was found between the VEGF expression and both the depth of invasion (P = 0.0001) and lymph node metastasis (P < 0.0001). With regard to p53, we compared the expression of VEGF with the mutation of p53, examined using polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) and direct sequencing in tumour samples obtained from 36 patients who we have reported previously. The VEGF expression was significantly correlated to p53 mutation (P = 0.0291). To evaluate the angiogenesis, microvascular density (MVD) was counted, and endothelial cells were stained immunohistochemically using anti-CD34 monoclonal antibody against 29 cases with invasion limited to the submucosal layer. The average MVD had a tendency to correlate to VEGF expression (P = 0.1626). The prognoses of patients with VEGFpositive primary tumours were significantly worse than for those with VEGF-negative primary tumours (P = 0.0077). We have assumed that VEGF contributes to aggressive characteristics in oesophageal carcinomas and that VEGF expression might be affected by p53 status.

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