Citation Details

Journal Article

Aging; Animals; Antigens, CD36; Cell Line; Dimerization; Ethylnitrosourea; Gene Deletion; Glycerides; Homozygote; Humans; Immunologic Deficiency Syndromes; Lipopeptides; Membrane Glycoproteins; Mice; Mice, Inbred C57BL; Mice, Knockout; Mutagenesis; Mutation; Oligopeptides; Peptidoglycan; Phenotype; Receptors, Cell Surface; Signal Transduction; Staphylococcal Infections; Staphylococcus aureus; Toll-Like Receptor 2; Toll-Like Receptors; Tumor Necrosis Factor-alpha; Zymosan

Toll-like receptor 2 (TLR2) is required for the recognition of numerous molecular components of bacteria, fungi and protozoa. The breadth of the ligand repertoire seems unusual, even if one considers that TLR2 may form heteromers with TLRs 1 and 6 (ref. 12), and it is likely that additional proteins serve as adapters for TLR2 activation. Here we show that an N-ethyl-N-nitrosourea-induced nonsense mutation of Cd36 (oblivious) causes a recessive immunodeficiency phenotype in which macrophages are insensitive to the R-enantiomer of MALP-2 (a diacylated bacterial lipopeptide) and to lipoteichoic acid. Homozygous mice are hypersusceptible to Staphylococcus aureus infection. Cd36(obl) macrophages readily detect S-MALP-2, PAM(2)CSK(4), PAM(3)CSK(4) and zymosan, revealing that some--but not all--TLR2 ligands are dependent on CD36. Already known as a receptor for endogenous molecules, CD36 is also a selective and nonredundant sensor of microbial diacylglycerides that signal via the TLR2/6 heterodimer.

Journal Article

Animals; Antineoplastic Agents; Benzocycloheptenes; Bioware; Breast Neoplasms; Carcinoma; Female; Hela Cells; Humans; K562 Cells; MDA-MB-231-D3H2LN cells; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Invasiveness; Neoplasm Metastasis; Oncogene Proteins; Protein kinase inhibitors; Proto-Oncogene Proteins; Receptor Protein-Tyrosine Kinases; Survival Analysis; Triazoles; Tumor Cells, Cultured; Xenograft Model Antitumor Assays

Accumulating evidence suggests important roles for the receptor tyrosine kinase Axl in cancer progression, invasion, metastasis, drug resistance, and patient mortality, highlighting Axl as an attractive target for therapeutic development. We have generated and characterized a potent and selective small-molecule inhibitor, R428, that blocks the catalytic and procancerous activities of Axl. R428 inhibits Axl with low nanomolar activity and blocked Axl-dependent events, including Akt phosphorylation, breast cancer cell invasion, and proinflammatory cytokine production. Pharmacologic investigations revealed favorable exposure after oral administration such that R428-treated tumors displayed a dose-dependent reduction in expression of the cytokine granulocyte macrophage colony-stimulating factor and the epithelial-mesenchymal transition transcriptional regulator Snail. In support of an earlier study, R428 inhibited angiogenesis in corneal micropocket and tumor models. R428 administration reduced metastatic burden and extended survival in MDA-MB-231 intracardiac and 4T1 orthotopic (median survival, >80 days compared with 52 days; P < 0.05) mouse models of breast cancer metastasis. Additionally, R428 synergized with cisplatin to enhance suppression of liver micrometastasis. Our results show that Axl signaling regulates breast cancer metastasis at multiple levels in tumor cells and tumor stromal cells and that selective Axl blockade confers therapeutic value in prolonging survival of animals bearing metastatic tumors.

Journal Article

Xen36, Xen 36, Staphylococcus aureus Xen36, IVIS

Wear of metal-on-metal (cobalt-chromium, Co-Cr particles) and metal-on-polyethylene (ultra-high-molecular-weight polyethylene, UHMWPE particles) bearing surfaces in hip prostheses is a major problem in orthopedics. This study aimed to compare the influence of Co-Cr and UHMWPE particles on the persistence of infection. Bioluminescent Staphylococcus aureus Xen36 were injected in air pouches prepared in subcutaneous tissue of immuno-competent BALB/c mice (control), as a model for the joint space, in the absence or presence of Co-Cr or UHMWPE particles. Bioluminescence was monitored longitudinally up to 21 days, corrected for absorption and reflection by the particles and expressed relative to the bioluminescence found in the presence of staphylococci only. After termination, air pouch fluid and air pouch membrane were cultured and histologically analyzed. Bioluminescence was initially lower in mice exposed to UHMWPE particles with staphylococci than in mice injected with staphylococci only, possibly because UHMWPE particles initially stimulated a higher macrophage presence in murine air pouch membranes. For mice exposed to Co-Cr particles with staphylococci, bioluminescence was observed to be higher in two out of six animals compared to the presence of staphylococci alone. In the majority of mice, infection risk in the absence or presence of Co-Cr and UHMWPE particles appeared similar, assuming that the longevity of an elevated bioluminescence is indicative of a higher infection risk. However, the presence of Co-Cr particles yielded a higher bioluminescence in two out of six mice, possibly because the macrophage degradative function was hampered by the presence of Co-Cr particles. (c) 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Journal Article

in vivo imaging; therapeutics; asthma; pulmonary diseases; noninvasive; infrared imaging; fluorescence molecular tomography; FMT; Fluorescence Imaging Agents

Animal models of pulmonary inflammation are critical for understanding the pathophysiology of asthma and for developing new therapies. Current conventional assessments in mouse models of asthma and chronic obstructive pulmonary disease rely on invasive measures of pulmonary function and terminal characterization of cells infiltrating into the lung. The ability to noninvasively visualize and quantify the underlying biological processes in mouse pulmonary models in vivo would provide a significant advance in characterizing disease processes and the effects of therapeutics. We report the utility of near-infrared imaging agents, in combination with fluorescence molecular tomography (FMT) imaging, for the noninvasive quantitative imaging of mouse lung inflammation in an ovalbumin (OVA)-induced chronic asthma model. BALB/c mice were intraperitoneally sensitized with OVA-Alum (aluminum hydroxide) at days 0 and 14, followed by daily intranasal challenge with OVA in phosphate-buffered saline from days 21 to 24. Dexamethasone and control therapies were given intraperitoneally 4 h before each intranasal inhalation of OVA from days 21 to 24. Twenty-four hours before imaging, the mice were injected intravenously with 5 nmol of the cathepsin-activatable fluorescent agent, ProSense 680. Quantification by FMT revealed in vivo cysteine protease activity within the lung associated with the inflammatory eosinophilia, which decreased in response to dexamethasone treatment. Results were correlated with in vitro laboratory tests (bronchoalveolar lavage cell analysis and immunohistochemistry) and revealed good correlation between these measures and quantification of ProSense 680 activation. We have demonstrated the ability of FMT to noninvasively visualize and quantify inflammation in the lung and monitor therapeutic efficacy in vivo.

Journal Article

Near infrared; NIF; near-infrared; intestinal inflammation

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