Citation Details

Journal Article

IVIS, Xen29, Xen 29, Staphylococcus aureus Xen29, Administration, Inhalation; Aerosols; Animals; Cell Line, Tumor; Cell Proliferation/drug effects; Cell Transformation, Neoplastic; Humans; Lung Neoplasms/drug therapy/genetics/*pathology/*secondary; Mice; Oncogenes/genetics; Plasmids/*administration & dosage/chemistry/*pharmacology; Polyethyleneimine/chemistry

Despite numerous efforts, drug based treatments for patients suffering from lung cancer remains poor. As a promising alternative, we investigated the therapeutic potential of BC-819 for the treatment of lung cancer in mouse tumor models. BC-819 is a novel plasmid DNA which encodes for the A-fragment of Diphtheria toxin and has previously been shown to successfully inhibit tumor growth in human clinical study of bladder carcinoma. In a first set of experiments, we examined in vitro efficacy of BC-819 in human lung cancer cell-lines NCI-H460, NCI-H358 and A549, which revealed >90% reduction of cell growth. In vivo efficacy was examined in an orthotopic mouse xenograft lung cancer model and in a lung metastasis model using luminescent A549-C8-luc adenocarcinoma cells. These cells resulted in peri- and intra-bronchiolar tumors upon intrabronchial application and parenchymal tumors upon intravenous injection, respectively. Mice suffering from these lung tumors were treated with BC-819, complexed to branched polyethylenimine (PEI) and aerosolized to the mice once per week for a period of 10 weeks. Using this regimen, growth of intrabronchially induced lung tumors was significantly inhibited (p = 0.01), whereas no effect could be observed in mice suffering from lung metastasis. In summary, we suggest that aerosolized PEI/BC-819 is capable of reducing growth only in tumors arising from the luminal part of the airways and are therefore directly accessible for inhaled BC-819.

Journal Article

IVIS, Xen29, Xen 29, Staphylococcus aureus Xen29, Acetates; Animals; *Biofilms; Bioprosthesis; Blood Vessel Prosthesis/*microbiology; Cattle; Colony Count, Microbial; Luminescent Measurements/*methods; Mice; Microbial Viability; Pericardium; *Photons; Polyesters; Polytetrafluoroethylene; Prospective Studies; Prosthesis-Related Infections/*diagnosis; Random Allocation; Silver Compounds; Staphylococcus aureus/isolation & purification/*physiology

OBJECTIVES: Biophotonic imaging was compared to standard enumeration method both for counting Staphylococcus aureus in biofilm and bacterial susceptibility tests of different graft materials. DESIGN: Prospective, randomized, controlled animal study. MATERIAL AND METHODS: Five types of vascular grafts were placed subcutaneously in 35 mice and challenged with bioluminescent S. aureus. The mice were divided into equal groups as follows: group A (polyester), group B (polytetrafluoroethylene), group C and D (two types of silver acetate-coated polyester) and group E (bovine pericardium). Controls were given only the bacteria. The bioluminescence signal of S. aureus, able to predict number of viable bacteria in biofilm without any manipulation, was measured at different time points. Five days postinfection, regular cultures of adherent bacteria on grafts were obtained. Comparative analyses between bioluminescence activity and culture enumeration were performed. RESULTS: The number of viable bacteria on silver-coated prostheses was the slightest, indicating superior bacterial resistance. The density of bacteria on polytetrafluoroethylene and polyester was comparable, with a non-significant advantage for polytetrafluoroethylene. Moreover, bioluminescence detected the number of viable S. aureus in biofilm more exactly compared to enumeration of bacteria. CONCLUSION: Bioluminescence imaging can be considered a useful tool to characterize susceptibility of any graft material to bacterial biofilm prior to implantation.

Journal Article

IVIS, Xen29, Xen 29, Staphylococcus aureus Xen29, Animals; Blood Glucose/metabolism; Cell Adhesion/drug effects; Cell Count; Cell Movement/drug effects; Chemokine CXCL2/pharmacology; Diabetes Mellitus, Type 1/blood/complications/*immunology/microbiology; Diabetes Mellitus, Type 2/blood/complications/*immunology/microbiology; Diet, High-Fat/adverse effects; Disease Models, Animal; Hyperglycemia/chemically induced/complications; Inflammation/blood/complications/immunology/microbiology; Leukocytes/cytology/drug effects/*immunology/microbiology; Male; Mice; Mice, Inbred C57BL; Phagocytes/cytology/drug effects/microbiology; Staphylococcus aureus/physiology

BACKGROUND: Patients suffering from diabetes show defective bacterial clearance. This study investigates the effects of elevated plasma glucose levels during diabetes on leukocyte recruitment and function in established models of inflammation. METHODOLOGY/PRINCIPAL FINDINGS: Diabetes was induced in C57Bl/6 mice by intravenous alloxan (causing severe hyperglycemia), or by high fat diet (moderate hyperglycemia). Leukocyte recruitment was studied in anaesthetized mice using intravital microscopy of exposed cremaster muscles, where numbers of rolling, adherent and emigrated leukocytes were quantified before and during exposure to the inflammatory chemokine MIP-2 (0.5 nM). During basal conditions, prior to addition of chemokine, the adherent and emigrated leukocytes were increased in both alloxan- (62+/-18% and 85+/-21%, respectively) and high fat diet-induced (77+/-25% and 86+/-17%, respectively) diabetes compared to control mice. MIP-2 induced leukocyte emigration in all groups, albeit significantly more cells emigrated in alloxan-treated mice (15.3+/-1.0) compared to control (8.0+/-1.1) mice. Bacterial clearance was followed for 10 days after subcutaneous injection of bioluminescent S. aureus using non-invasive IVIS imaging, and the inflammatory response was assessed by Myeloperoxidase-ELISA and confocal imaging. The phagocytic ability of leukocytes was assessed using LPS-coated fluorescent beads and flow cytometry. Despite efficient leukocyte recruitment, alloxan-treated mice demonstrated an impaired ability to clear bacterial infection, which we found correlated to a 50% decreased phagocytic ability of leukocytes in diabetic mice. CONCLUSIONS/SIGNIFICANCE: These results indicate that reduced ability to clear bacterial infections observed during experimentally induced diabetes is not due to reduced leukocyte recruitment since sustained hyperglycemia results in increased levels of adherent and emigrated leukocytes in mouse models of type 1 and type 2 diabetes. Instead, decreased phagocytic ability observed for leukocytes isolated from diabetic mice might account for the impaired bacterial clearance.

Journal Article

IVIS, Xen29, Xen 29, Staphylococcus aureus Xen29, Animals; Disease Models, Animal; Female; Mice; Mice, Inbred C57BL; Pneumonectomy/*adverse effects; Postoperative Complications/*surgery; Stem Cell Transplantation/*methods; Thoracic Cavity/*surgery; Thoracoplasty/*methods; Tissue Engineering/*methods

BACKGROUND: Transfer of viable tissue flaps and thoracoplasty are effective against pleural space complications after pneumonectomy but highly disfiguring. The aim of this study was to explore the possibility of engineered tissue to treat space complications after pneumonectomy. METHODS: A left pneumonectomy was performed in mice, and the cavity immediately filled with the cellularized collagen matrices. First, bone marrow derived-mesenchymal stroma cells with luciferase expression were used as donor cells to evaluate cell viability and angiogenesis using bioluminescence imaging. Second, using bone marrow cells from GFP mice, histologic evaluation, immunohistochemistry for von Willebrand Factor, and flow cytometric analysis was performed compared with acellular matrix implants. The effect on bacterial clearance was examined using an empyema model with Staphylococcus aureus expressing luciferase. RESULTS: Embedded cells proliferated within the denatured collagen matrices ex vivo. In vivo, bioluminescent imaging activity could be detected till day 8, and the slope (suggesting rate of perfusion with luciferin) increased with time up to day 6 but decreased after day 7. Although GFP-positive donor cells decreased with time, total cellularity increased. Furthermore, vessels stained by von Willebrand factor were significantly increased. Both cellularized and acellularized matrices showed bacterial clearance in vivo. CONCLUSIONS: Cells within collagen matrices survive in the thoracic cavity at early time points. Cellularized matrices quickly lead to neovascularization and recipient cell infiltration. Both cellularized and acellularized matrices show bacterial clearance in vivo. This study indicates the potential feasibility of a novel tissue engineering approach to problems of the postpneumonectomy space.

Journal Article

MMPSense, IVIS, Acrylamides/pharmacology/*therapeutic use; Animals; Arthritis, Experimental/*drug therapy/metabolism/pathology; Cartilage/*metabolism/pathology; Fibroblasts/metabolism/pathology; Humans; Inflammation/metabolism/pathology; Leukocytes/*drug effects/metabolism/pathology; Mice; Nicotinamide Phosphoribosyltransferase/*antagonists & inhibitors; Piperidines/pharmacology/*therapeutic use

OBJECTIVE: To assess the ability of pre-B cell colony-enhancing factor (PBEF) to regulate inflammation and degradative processes in inflammatory arthritis, using the small molecule inhibitor APO866 in human fibroblasts in vitro and in murine collagen-induced arthritis (CIA). METHODS: Enzyme-linked immunosorbent assays were used to examine regulation of expression of metalloproteinases and chemokines in human fibroblasts. The role of PBEF was further examined using APO866 in mice with CIA, with effects on disease activity assessed using radiography, histology, in vivo imaging, and quantitative polymerase chain reaction (qPCR). RESULTS: In vitro activation of human fibroblasts with PBEF promoted expression of matrix metalloproteinase 3 (MMP-3), CCL2, and CXCL8, an effect inhibited by APO866. In mice with CIA, early intervention with APO866 inhibited synovial inflammation, including chemokine-directed leukocyte infiltration, and reduced a systemic marker of inflammation, serum hyaluronic acid. APO866 blockade led to reduced expression of MMP-3 and MMP-13 in joint extracts and to a reduction in a systemic marker of cartilage erosion, serum cartilage oligomeric matrix protein. Radiologic images revealed that APO866 protected against bone erosion, while qPCR demonstrated inhibition of RANKL expression. In mice with established disease, APO866 reduced synovial inflammation and cartilage destruction, and halted bone erosion. In addition, APO866 reduced the activity of MMP-3, CCL2, and RANKL in vivo, and inhibited production of CCL2 and RANKL in synovial explants from arthritic mice, a result that was reversed with nicotinamide mononucleotide. CONCLUSION: These findings confirm PBEF to be an important regulator of inflammation, cartilage catabolism, and bone erosion, and highlight APO866 as a promising therapeutic agent for targeting PBEF activity in inflammatory arthritis.