Effects of Once-Weekly Exenatide on Cardiovascular Outcomes in Type 2 Diabetes.

Abstract BACKGROUND: The cardiovascular effects of adding once-weekly treatment with exenatide to usual care in patients with type 2 diabetes are unknown. METHODS: We randomly assigned patients with type 2 diabetes, with or without previous cardiovascular disease, to receive subcutaneous injections of extended-release exenatide at a dose of 2 mg or matching placebo once weekly. The primary composite outcome was the first occurrence of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke. The coprimary hypotheses were that exenatide, administered once weekly, would be noninferior to placebo with respect to safety and superior to placebo with respect to efficacy. RESULTS: In all, 14,752 patients (of whom 10,782 [73.1%] had previous cardiovascular disease) were followed for a median of 3.2 years (interquartile range, 2.2 to 4.4). A primary composite outcome event occurred in 839 of 7356 patients (11.4%; 3.7 events per 100 person-years) in the exenatide group and in 905 of 7396 patients (12.2%; 4.0 events per 100 person-years) in the placebo group (hazard ratio, 0.91; 95% confidence interval [CI], 0.83 to 1.00), with the intention-to-treat analysis indicating that exenatide, administered once weekly, was noninferior to placebo with respect to safety (P<0.001 for noninferiority) but was not superior to placebo with respect to efficacy (P=0.06 for superiority). The rates of death from cardiovascular causes, fatal or nonfatal myocardial infarction, fatal or nonfatal stroke, hospitalization for heart failure, and hospitalization for acute coronary syndrome, and the incidence of acute pancreatitis, pancreatic cancer, medullary thyroid carcinoma, and serious adverse events did not differ significantly between the two groups. CONCLUSIONS: Among patients with type 2 diabetes with or without previous cardiovascular disease, the incidence of major adverse cardiovascular events did not differ significantly between patients who received exenatide and those who received placebo. (Funded by Amylin Pharmaceuticals; EXSCEL ClinicalTrials.gov number, NCT01144338 .)

P2X(7) nucleotide receptor mediation of membrane pore formation and superoxide generation in human promyelocytes and neutrophils

The P2X(7) receptor, which induces cation channel opening imparting significant permeability to Ca2+ and pore formation with changes in the plasma membrane potential, has been known to be rather restrictedly expressed in cells of the macrophage lineage including dendrites, mature macrophages, and microglial cells. However, we show here that the P2X7 receptor is also expressed in cells of granulocytic lineage such as HL-60 promyelocytes, granulocytic differentiated cells, and neutrophils. Exposure of these cells to 2&apos;,3&apos;-O-(4-benzoyl)benzoyl-ATP (BzATP) triggered intracellular Ca2+ rise through the mediation of phospholipase C-independent and suramin-sensitive pathways. BzATP also induced depolarization of the plasma membrane in the absence of extracellular Ca2+, whereas it hyperpolarized the cells in the presence of external Ca2+, probably in part through the activation of Ca2+-activated K+ channels. However, the hyperpolarization phenomenon was markedly attenuated in differentiated HL-60 cells and neutrophils. RT-PCR and Northern blot analysis revealed the presence of P2X7 receptors on both HL-60 and neutrophil-like cells. This was further confirmed by pore formation through which the uptake of Lucifer yellow and YO-PRO1 occurred on BzATP treatment. BzATP stimulated in a concentration-dependent manner the production of superoxide in differentiated HL-60 cells via a pathway partially dependent on extracellular Ca2+. Moreover, in human neutrophils, BzATP was a more effective inducer of superoxide generation than PMA. Taken together, this is a first demonstration of the expression of P2X7 receptors on neutrophils, which shows that the receptor is functionally involved in the defense mechanism by activation of the respiratory burst pathway.X1188sciescopu

Targeted delivery of microRNA-145 to metastatic breast cancer by peptide conjugated branched PEI gene carrier

Development of a targeted polymeric gene delivery system is essential for reducing the non-specific uptake and toxicity of the gene carriers. In this study, we have tested the specificity of the cell penetrating peptide (DS 4-3), screened by phage display technique, towards metastatic breast cancer cells. This peptide has shown specificity towards metastatic breast cancer cells, which was confirmed through endocytosis inhibition study. Furthermore, the DS 4-3 peptide was conjugated to bPEI, to deliver the therapeutic miR-145. Tumor suppressor miR-145 inhibited tumor cell growth, and significantly suppressed cell invasion. The DS 4-3 peptide conjugated branched PEI (DSbPEI)/pLuc nanoparticles showed increased transfection in malignant murine breast cancer cells at the neutral surface charge (N/P molar ratio of 3), compared to scramble peptide conjugated bPEI/pLuc nanoparticles, without causing any cytotoxicity. This specific increase in transfection with DS-bPEI/pLuc nanoparticles was not found in the cancer cells that originated from different tissue, such as HeLa cervical cancer cells, or in the normal cells, such as NIH-3T3 murine fibroblast cells. Thus, the specific transfection of miR-145 in metastatic breast cancer cells mediated by DS-bPEI resulted in enhanced reduction in proliferation.X1199sciescopuskc

Tumor Suppressor p53 Gene Therapy mediated by PEI-coated, thermally crosslinked Superparamagnetic iron oxide nanoparticles

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Multifunctional silica nanotubes for dual-modality gene delivery and MR imaging

This work demonstrated the development of multifunctional silica nanotubes (SNT) by functionalization of their inner void and outer surface with magnetic-fluorescence nanocomposites and cationic polymers, respectively. The successful construction of BPEI-SNT was established by electron energy loss spectroscopy in conjugation with standard analytical tools. The mean fluorescence intensity in a FACS assay, a luciferase gene expression assay and a confocal fluorescence study demonstrated the efficacy of BPEI-SNT as a gene delivery vector. Endocytotic uptake was also demonstrated by the colocalization of LysoTracker Red (R) and green fluorescent quantum dots. Moreover, enhanced magnetic resonance imaging revealed the potential of the BPEI-SNT nanocomposite to act as a dual-modality nano-device. (C) 2010 Elsevier Ltd. All rights reserved.X113535sciescopu

MR Traceable Delivery of p53 Tumor Suppressor Gene by PEI-Functionalized Superparamagnetic Iron Oxide Nanoparticles

Cancer gene therapy involves the replacement of missing or altered genes with healthy ones. In this paper, we have proposed tumor suppressor gene-carrying superparamagnetic iron oxide nanoparticles (SPIONs) for anti-cancer gene therapy. Thermally crosslinked SPIONs (TCL-SPIONs) were conjugated with branched polyethylenimine (PEI 1800 Da) by EDC-NHS chemistry for p53 plasmid DNA delivery. The morphology of the bPEI conjugated TCL-SPIONs (bPEI-TCL-SPION) and pDNA-loaded bPEI-TCL-SPION nanoparticles was measured using transmission electron microscopy (TEM). The particle sizes of the pDNA-loaded bPEI-TCL-SPION nanoparticles were also confirmed by dynamic light scattering, and ranged from 100 to 130 nm, depending on the molar charge ratio. The fluorescently labeled pDNA was complexed with bPEI-TCL-SPION and its intracellular internalization was investigated using confocal microscopy. The p53 plasmid-loaded bPEI-TCL-SPION nanoparticles achieved significantly higher p53 tumor suppressor gene expression and cellular viability compared to positive controls. The expressed wild-type p53 protein suppressed tumor cell proliferation as compared to the mutant control. When transgene expression of the p53 tumor suppressor gene was evaluated at the mRNA level and quantified using real-time PCR, the results were highly dependent on the molar charge ratio (NIP) as well as the cancer cell type. SPIONs internalized within cancer cells were tracked by magnetic resonance (MR) imaging. It was concluded that bPEI-TCL-SPION could be used as efficient gene delivery carriers that can be tracked by MR imaging.X115350sciescopu