Citation Details

Journal Article

AngioSense, Animals; Antineoplastic Agents/therapeutic use; Diagnostic Imaging/*methods; Female; Mammary Neoplasms, Animal/metabolism/pathology; Mice; Mice, Nude; Neoplasm Transplantation; Neovascularization, Pathologic/drug therapy/*pathology

In vivo angiogenesis assays provide more physiologically relevant information about tumor vascularization than in vitro studies because they take the complex interactions among cancer cells, endothelial cells, mural cells, and tumor stroma into consideration. Traditional microscopic assessment of vascular density conducted by immunostaining of tissue sections or by lectin angiogram visualization of tumor vessels is invasive and requires the sacrifice of tumor-bearing animals. Therefore, it prohibits longitudinal time-course observation in a single animal and requires a large number of animals at each time point to derive statistically-meaningful observations. Additionally, heterogenous behavior among different tumors will inevitably introduce individual biological variance that may obscure reliable interpretation of the results. While various artificial in vivo angiogenesis assays, such as the Matrigel implant assay, chick chorioallatoic membrane assay, and dorsal skin fold chamber assay have been developed and employed to more directly observe the progression of physiological angiogenesis, they can not appropriately assess tumor angiogenic progression or tumor vascular regression in response to therapeutic intervention. Here, we describe a noninvasive method and a detailed protocol that we have developed and optimized using the Olympus OV-100 in vivo imaging system for real-time high-resolution visualization and assessment of tumor angiogenesis and vascular response to anticancer therapies in live animals. We show that using this approach, tumor vessels can be monitored longitudinally through the whole vasculogenesis and angiogenesis process in the same mouse. Further, morphologic changes of the same vessel prior to and after drug treatments can be captured with microscopic high resolution. Moreover, the multichannel co-imaging capability of the OV-100 allows us to analyze and compare tumor vessel permeability before and after antiangiogenesis therapy by employing a near-infrared blood pool reagent, or by visualizing improved cytotoxic drug delivery upon tumor vessel normalization by using a fluorophore tagged drug. This noninvasive method can be readily applied to orthotopically transplanted breast cancer models as well as to subcutaneously-transplanted tumor models.

Journal Article

Adenoviridae/genetics, Anesthesia, Animals, Firefly Luciferin/administration & dosage/pharmacology, *Gene Expression Regulation/drug effects, Genetic Vectors/genetics, Luciferases/metabolism, Luminescent Measurements/*methods, Mice, Photons, Whole Body Imaging/*methods IVIS, Xenogen, Xen5

Molecular imaging offers many unique opportunities to study biological processes in intact organisms. Bioluminescence is the emission of light from biochemical reactions that occur within a living organism. Luciferase has been used as a reporter gene in transgenic mice but, until bioluminescence imaging was described, the detection of luciferase activity required either sectioning of the animal or excision of tissue and homogenization to measure enzyme activities in a conventional luminometer. Bioluminescence imaging (BLI) is based on the idea that biological light sources can be incorporated into cells and animal models artificially that does not naturally express the luminescent genes. This imaging modality has proven to be a very powerful methodology to detect luciferase reporter activity in intact animal models. This form of optical imaging is low cost and noninvasive and facilitates real-time analysis of disease processes at the molecular level in living organisms. Bioluminescence provides a noninvasive method to monitor gene expression in vivo and has enormous potential to elucidate the pathobiology of lung diseases in intact mouse models, including models of inflammation/injury, infection, and cancer.

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

A549-luc-C8, A549-luc, IVIS, Bioware, Calcium/chemistry; Cell Line; Cell-Penetrating Peptides/administration & dosage/*chemistry; Drug Carriers/administration & dosage/adverse effects/*chemistry; *Gene Silencing; Genetic Therapy/*methods; Humans; Luciferases; Nanoparticles/administration & dosage/chemistry; RNA, Small Interfering/*administration & dosage/chemistry; Tissue Distribution

The development of short-interfering RNA (siRNA) offers new strategies for manipulating specific genes responsible for pathological disorders. Myriad cationic polymer and lipid formulations have been explored, but an effective, non-toxic carrier remains a major barrier to clinical translation. Among the emerging candidates for siRNA carriers are cell penetrating peptides (CPPs), which can traverse the plasma membrane and facilitate the intracellular delivery of siRNA. Previously, a highly efficient and non-cytotoxic means of gene delivery was designed by complexing plasmid DNA with CPPs, then condensing with calcium. Here, the CPP TAT and a longer, 'double' TAT (dTAT) were investigated as potential carriers for siRNA. Various N/P ratios and calcium concentrations were used to optimize siRNA complexes in vitro. Upon addition of calcium, 'loose' siRNA/CPP complexes were condensed into small nanoparticles. Knockdown of luciferase expression in the human epithelial lung cell line A549-luc-C8 was high (up to 93%) with no evidence of cytotoxicity. Selected formulations of the dTAT complexes were dosed intravenously up to 1000 mg/kg with minimal toxicity. Biodistribution studies revealed high levels of gene knockdown in the lung and muscle tissue suggesting these simple vectors may offer a translatable approach to siRNA delivery.

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.