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      1. Author :
        Jeffrey D Peterson; Timothy P LaBranche; Kristine O Vasquez; Sylvie Kossodo; Michele Melton; Randall Rader; John T Listello; Mark A Abrams; Thomas P Misko
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2010
      5. Publication :
        Arthritis Research & Therapy
      6. Products :
      7. Volume :
        12
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        N/A
      11. Keywords :
        optical tomography; in vivo imaging; inflammation; Fluorescence molecular tomographic; FMT
      12. Abstract :
        Introduction: Standard measurements used to assess murine models of rheumatoid arthritis, notably paw thickness and clinical score, do not align well with certain aspects of disease severity as assessed by histopathology. We tested the hypothesis that non-invasive optical tomographic imaging of molecular biomarkers of inflammation and bone turnover would provide a superior quantitative readout and would discriminate between a disease-modifying anti-rheumatic drug (DMARD) and a non-DMARD treatment.

        Methods: Using two protease-activated near-infrared fluorescence imaging agents to detect inflammation-associated cathepsin and matrix metalloprotease activity, and a third agent to detect bone turnover, we quantified fluorescence in paws of mice with collagen antibody-induced arthritis. Fluorescence molecular tomographic (FMT) imaging results, which provided deep tissue detection and quantitative readouts in absolute picomoles of agent fluorescence per paw, were compared with paw swelling, clinical scores, a panel of plasma biomarkers, and histopathology to discriminate between steroid (prednisolone), DMARD (p38 mitogen-activated protein kinase (MAPK) inhibitor) and non-DMARD (celecoxib, cyclooxygenase-2 (COX-2) inhibitor) treatments.

        Results: Paw thickness, clinical score, and plasma biomarkers failed to discriminate well between a p38 MAPK inhibitor and a COX-2 inhibitor. In contrast, FMT quantification using near-infrared agents to detect protease activity or bone resorption yielded a clear discrimination between the different classes of therapeutics. FMT results agreed well with inflammation scores, and both imaging and histopathology provided clearer discrimination between treatments as compared with paw swelling, clinical score, and serum biomarker readouts.

        Conclusions: Non-invasive optical tomographic imaging offers a unique approach to monitoring disease pathogenesis and correlates with histopathology assessment of joint inflammation and bone resorption. The specific use of optical tomography allowed accurate three-dimensional imaging, quantitation in picomoles rather than intensity or relative fluorescence, and, for the first time, showed that non-invasive imaging assessment can predict the pathologist's histology inflammation scoring and discriminate DMARD from non-DMARD activity.
      13. URL :
        http://arthritis-research.com/content/12/3/R105
      14. Call Number :
        PKI @ sarah.piper @
      15. Serial :
        4513
      1. Author :
        Filip K. Swirski, Ralph Weissleder and Mikael J. Pittet
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        N/A
      5. Publication :
        Arteriosclerosis, Thrombosis, and Vascular Biology
      6. Products :
      7. Volume :
        N/A
      8. Issue :
        N/A
      9. Page Numbers :
        N/A
      10. Research Area :
        Cardiovascular Research
      11. Keywords :
        atherosclerosis; in vivo imaging; monocytes; VivoTag; FMT; fluorescence molecular tomography
      12. Abstract :
        Monocytes and macrophages play active roles in atherosclerosis, a chronic inflammatory disease that is a leading cause of death in the developed world. The prevailing paradigm states that, during human atherogenesis, monocytes accumulate in the arterial intima and differentiate into macrophages, which then ingest oxidized lipoproteins, secrete a diverse array of proinflammatory mediators, and eventually become foam cells, the key constituents of a vulnerable plaque. Yet monocytes are heterogeneous. In the mouse, one subset (Ly-6Chi) promotes inflammation, expands in hypercholesterolemic conditions, and selectively gives rise to macrophages in atheromata. A different subset (Ly-6Clo) attenuates inflammation and promotes angiogenesis and granulation tissue formation in models of tissue injury, but its role in atherosclerosis is largely unknown. In the human, monocyte heterogeneity is preserved but it is still unresolved how subsets correspond functionally. The contradistinctive properties of these cells suggest commitment for specific function before infiltrating tissue. Such commitment argues for discriminate targeting of deleterious subsets while sparing host defense and repair mechanisms. In addition to advancing our understanding of atherosclerosis, the ability to target and image monocyte subsets would allow us to evaluate drugs designed to selectively inhibit monocyte subset recruitment or function, and to stratify patients at risk for developing complications such as myocardial infarction or stroke. In this review we summarize recent advances of our understanding of the behavioral heterogeneity of monocytes during disease progression and outline emerging molecular imaging approaches to address key questions in the field.
      13. URL :
        http://atvb.ahajournals.org/cgi/content/abstract/ATVBAHA.108.180521v1
      14. Call Number :
        PKI @ sarah.piper @
      15. Serial :
        4569
      1. Author :
        Laurie E. Littlepage; Mark D. Sternlicht; Nathalie Rougier; Joanna Phillips; Eugenio Gallo; Ying Yu; Kurt Williams; Audrey Brenot; Jeffrey I. Gordon; Zena Werb
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2010
      5. Publication :
        Cancer Research
      6. Products :
      7. Volume :
        70
      8. Issue :
        6
      9. Page Numbers :
        N/A
      10. Research Area :
        Cancer
      11. Keywords :
        matrix metalloproteinase; neuroendocrine; prostate cancer; metatasis
      12. Abstract :
        Prostate cancer is the leading form of cancer in men. Prostate tumors often contain neuroendocrine differentiation, which correlates with androgen-independent progression and poor prognosis. Matrix metalloproteinases (MMP), a family of enzymes that remodel the microenvironment, are associated with tumorigenesis and metastasis. To evaluate MMPs during metastatic prostatic neuroendocrine cancer development, we used transgenic mice expressing SV40 large T antigen in their prostatic neuroendocrine cells, under the control of transcriptional regulatory elements from the mouse cryptdin-2 gene (CR2-TAg). These mice have a stereotypical pattern of tumorigenesis and metastasis. MMP-2, MMP-7, and MMP-9 activities increased concurrently with the transition to invasive metastatic carcinoma, but they were expressed in different prostatic cell types: stromal, luminal epithelium, and macrophages, respectively. CR2-TAg mice treated with AG3340/Prinomastat, an MMP inhibitor that blocks activity of MMP-2, MMP-9, MMP-13, and MMP-14, had reduced tumor burden. CR2-TAg animals were crossed to mice homozygous for null alleles of MMP-2, MMP-7, or MMP-9 genes. At 24 weeks CR2-TAg; MMP-2-/- mice showed reduced tumor burden, prolonged survival, decreased lung metastasis, and decreased blood vessel density, whereas deficiencies in MMP-7 or MMP-9 did not influence tumor growth or survival. Mice deficient for MMP-7 had reduced endothelial area coverage and decreased vessel size, and mice lacking MMP-9 had increased numbers of invasive foci and increased perivascular invasion, as well as decreased tumor blood vessel size. Together, these results suggest distinct contributions by MMPs to the progression of aggressive prostate tumor and to helping tumors cleverly find alternative routes to malignant progression.
      13. URL :
        http://cancerres.aacrjournals.org/content/70/6/2224.abstract
      14. Call Number :
        PKI @ sarah.piper @
      15. Serial :
        4490
      1. Author :
        Thomas Christen, Matthias Nahrendorf, Moritz Wildgruber, Filip K. Swirski, Elena Aikawa, Peter Waterman, Koichi Shimizu, Ralph Weissleder and Peter Libby
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2009
      5. Publication :
        Circulation
      6. Products :
      7. Volume :
        119
      8. Issue :
        14
      9. Page Numbers :
        N/A
      10. Research Area :
        Cardiovascular Research
      11. Keywords :
        In vivo imaging; inflammation; leukocytes; rejection; transplantation; fluorescence molecular tomography; FMT; Prosense
      12. Abstract :
        Background: Clinical detection of transplant rejection by repeated endomyocardial biopsy requires catheterization and entails risks. Recently developed molecular and cellular imaging techniques that visualize macrophage host responses could provide a noninvasive alternative. Yet, which macrophage functions may provide useful markers for detecting parenchymal rejection remains uncertain.

        Methods and Results: We transplanted isografts from B6 mice and allografts from Balb/c mice heterotopically into B6 recipients. In this allograft across major histocompatability barriers, the transplanted heart undergoes predictable progressive rejection, leading to graft failure after 1 week. During rejection, crucial macrophage functions, including phagocytosis and release of proteases, render these abundant innate immune cells attractive imaging targets. Two or 6 days after transplantation, we injected either a fluorescent protease sensor or a magnetofluorescent phagocytosis marker. Histological and flow cytometric analyses established that macrophages function as the major cellular signal source. In vivo, we obtained a 3-dimensional functional map of macrophages showing higher phagocytic uptake of magnetofluorescent nanoparticles during rejection using magnetic resonance imaging and higher protease activity in allografts than in isografts using tomographic fluorescence. We further assessed the sensitivity of imaging to detect the degree of rejection. In vivo imaging of macrophage response correlated closely with gradually increasing allograft rejection and attenuated rejection in recipients with a genetically impaired immune response resulting from a deficiency in recombinase-1 (RAG-1-/-).

        Conclusions: Molecular imaging reporters of either phagocytosis or protease activity can detect cardiac allograft rejection noninvasively, promise to enhance the search for novel tolerance-inducing strategies, and have translational potential.
      13. URL :
        http://circ.ahajournals.org/cgi/content/abstract/circulationaha;119/14/1925
      14. Call Number :
        PKI @ sarah.piper @
      15. Serial :
        4640
      1. Author :
        N/A
      2. Title :
      3. Type :
        Journal Article
      4. Year :
        2009
      5. Publication :
        Circulation
      6. Products :
      7. Volume :
        119
      8. Issue :
        20
      9. Page Numbers :
        N/A
      10. Research Area :
        Cardiovascular Research
      11. Keywords :
        In vivo imaging; MMPSense
      12. Abstract :
        An extract of the first 250 words of the full text is provided, because this article has no abstract:

        Formation of unstable atherosclerotic plaque in the internal carotid artery carries a high risk for emboli and subsequent cerebral ischemic events. The fibrous cap of such a plaque may become thin and rupture as a result of the depletion of matrix components through the activation of proteolytic enzymes such as matrix-degrading proteinases. Enhanced matrix breakdown has been attributed primarily to a family of matrix-degrading metalloproteinases (MMPs) that are highly concentrated in atherosclerotic plaques by inflammatory cells (eg, macrophages, foam cells), smooth muscle cells and endothelial cells.

        Elevated serum MMP-9 concentration is associated with carotid plaque instability and the presence of infiltrated macrophages. Furthermore, analysis of the presence of MMP-9 protein by ELISA within excised carotid plaques revealed high MMP-9 protein mass in calcified segments at or near the carotid bifurcation and in segments with intraplaque hemorrhage. Gelatin zymography showed an increased gelatinase activity of MMP-9 in these segments. These data favor the important role of MMP-9 in the pathogenesis of plaque instability. We analyzed the topographic distribution of MMPs within an excised human carotid plaque by applying multispectral near-infrared fluorescence (NIRF) imaging (IVIS Spectrum, Caliper Life Sciences, Hopkinton, Mass).

        A surgical endarterectomy was performed on a 74-year-old women with a left-sided, symptomatic, >70% carotid stenosis. Immediately after endarterectomy, the plaque was placed in PBS and transported to the NIRF system. The plaque was then stretched out and fixed on a silicon plate with 25G needles. A PBS NIRF image was generated from both the intraluminal and extraluminal side of the . . .
      13. URL :
        http://circ.ahajournals.org/cgi/content/extract/119/20/e534
      14. Call Number :
        PKI @ sarah.piper @
      15. Serial :
        4644