Citation Details

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.

Journal Article

MMPSense, IVIS

The Standard measures of experimental arthritis fail to detect, visualize, and quantify early inflammation and disease activity. Here, we describe the use of an injectable MMP-activated fluorescence agent for in vivo quantification of acute inflammation produced by collagen-antibody-induced arthritis (CAIA) in CC chemokine receptor-2 (Ccr2(-/-)) null mice. Although Ccr2(-/-) DBA1/J mice were highly susceptible to and rapidly developed CAIA, the standard clinical assessment of fore or hind paw thicknesses was unable to detect significant acute inflammatory changes (days 3-10). Remarkably, noninvasive, in situ, MMP-activatable fluorescent imaging of Ccr2(-/-) DBA1/J mice with CAIA displayed acute joint pathology in advance of clinically measurable acute inflammation (days 5, 7, and 10). These results were confirmed by the histology of ankle joints, which showed significant inflammation, bone loss, and synovial hyperplasia, compared to control mice at postimmunization day 5. The MMP-mediated fluorescence technique holds tremendous implications for quantifiable examination of arthritis disease activity of acute joint inflammation.

Journal Article

MMPSense, IVIS, Atherosclerosis/complications/*diagnosis; Carotid Stenosis/*diagnosis/etiology; Diagnostic Imaging/*methods; Humans; Reproducibility of Results

BACKGROUND: There is increasing evidence that plaque vulnerability, rather than the degree of stenosis, is important in predicting the occurrence of subsequent cerebral ischemic events in patients with carotid artery stenosis. The many imaging modalities currently available have different properties with regard to the visualization of the extent of vulnerability in carotid plaque formation. METHODS: Original published studies were identified using the MEDLINE database (January 1966 to March 2008). Manual cross-referencing was also performed. RESULTS: There is no single imaging modality that can produce definitive information about the state of vulnerability of an atherosclerotic plaque. Each has its own specific drawbacks, which may be the use of ionizing radiation or nephrotoxic contrast agents, an invasive character, low patient tolerability, or simply the paucity of information obtained on plaque vulnerability. Functional molecular imaging techniques such as positron emission tomography (PET), single photon emission-computed tomography (SPECT) and near infra-red spectroscopy (NIRS) do seem able accurately to visualize and even quantify features of plaque vulnerability and its pathophysiologic processes. Promising new techniques like near infra-red fluorescence imaging are being developed and may be beneficial in this field. CONCLUSION: There is a promising role for functional molecular imaging modalities like PET, SPECT, or NIRS related to improvement of selection criteria for carotid intervention, especially when combined with CT or MRI to add further anatomical details to molecular information. Further information will be needed to define whether and where this functional molecular imaging will fit into a clinical strategy.

Journal Article

in vivo imaging; MMPSense; microRNA 21; glioma

Substantial data indicate that microRNA 21 (miR-21) is significantly elevated in glioblastoma (GBM) and in many other tumors of various origins. This microRNA has been implicated in various aspects of carcinogenesis, including cellular proliferation, apoptosis, and migration. We demonstrate that miR-21 regulates multiple genes associated with glioma cell apoptosis, migration, and invasiveness, including the RECK and TIMP3 genes, which are suppressors of malignancy and inhibitors of matrix metalloproteinases (MMPs). Specific inhibition of miR-21 with antisense oligonucleotides leads to elevated levels of RECK and TIMP3 and therefore reduces MMP activities in vitro and in a human model of gliomas in nude mice. Moreover, downregulation of miR-21 in glioma cells leads to decreases of their migratory and invasion abilities. Our data suggest that miR-21 contributes to glioma malignancy by downregulation of MMP inhibitors, which leads to activation of MMPs, thus promoting invasiveness of cancer cells. Our results also indicate that inhibition of a single oncomir, like miR-21, with specific antisense molecules can provide a novel therapeutic approach for “physiological” modulation of multiple proteins whose expression is deregulated in cancer.

Journal Article

Molecular imaging; Abdominal aortic aneurysm; Optical imaging; Pre-clinical; Endovascular imaging; Matrix metalloproteinase; in vivo imaging; MMPSense

Objectives: We present a method to quantify the inflammatory processes that drive abdominal aortic aneurysm (AAA) development that may help predict the rate of growth and thus guide medical and surgical management. We use an in vivo optical molecular imaging approach to quantify protease activity within the walls of AAAs in a rodent model.

Methods: AAAs were generated in mice by topical application of calcium chloride, followed by the administration of the MMP inhibitor doxycycline for 3 months. After this time period, an enzyme-activatable optical molecular imaging agent sensitive to MMP activity was administered, and MMP proteolytic activity was measured in vivo. Histology and in situ zymography were performed for validation. AAAs were also generated in rats, and MMP activity within the walls of the AAAs was also quantified endovascularly.

Results: A dose-dependent response of AAA growth rate to doxycycline administration was demonstrated, with high doses of the drug resulting in nearly complete suppression of aneurysm formation. There was a direct relationship between the rate of aneurysmal growth and measured MMP activity, with a linear best-fit well approximating the relationship. We additionally performed endovascular imaging of AAAs in rats and demonstrated a similar suppression of intramural MMP activity following doxycycline administration.

Conclusions: We present an in vivo evaluation of MMP activity within the walls of AAAs in rodents and show a direct, linear relationship between proteolytic activity and aneurysmal growth. We also illustrate that this functional imaging method can be performed endovascularly, demonstrating potential pre-clinical and clinical applications.