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

In-stent restenosis; Mouse; Stent; Animal model; in vivo imaging; MMPSense FAST; FMT

Background and aims: In-stent restenosis (ISR) is the major complication that occurs after percutaneous coronary interventions to facilitate coronary revascularization. Herein we described a simple and cost-effective model, which reproduces important features of ISR in the mouse.

Methods and results: Microvascular bare metal stents were successfully implanted in the abdominal aorta of atherosclerotic ApoE-null mice. Patency of implanted stents was interrogated using ultrasound biomicroscopy. Aortas were harvested at different time points after implantation and processed for histopathological analysis. Thrombus formation was histologically detected after 1 day. Leukocyte adherence and infiltration were evident after 7 days and decreased thereafter. Neointimal formation, neointimal thickness and luminal stenosis simultaneously increased up to 28 days after stent implantation. Using multichannel fluorescence molecular tomography (FMT) for spatiotemporal resolution of MMP activities, we observed that MMP activity in the stented aorta of Apo-E null mice was 2-fold higher than that of wild-type mice. Finally, we compared neointimal formation in response to stenting in two genetically different mouse strains. In-stent neointimas in FVB/NJ mice were 2-fold thicker than in C57BL/6J mice (p=0.002).

Conclusion: We have developed a model that can take advantage of the multiple genetic resources available for the mouse to study the mechanisms of in-stent restenosis.

Journal Article

Animals; B16-F10-luc-G5 cells; Bioware; Cytotoxicity Tests, Immunologic; Female; Melanoma, Experimental; Mice; Mice, Inbred C57BL; Neoplasm Metastasis; Ultrasonic Therapy

This study aims to assess the risk of high intensity focused ultrasound (HIFU) therapy on the incidence of distant metastases and to investigate its association with HIFU-elicited anti-tumor immunity in a murine melanoma (B16-F10) model. Tumor-bearing legs were amputated immediately after or 2 days following HIFU treatment to differentiate the contribution of the elicited anti-tumor immunity. In mice undergoing amputation immediately after mechanical, thermal, or no HIFU treatment, metastasis rates were comparable (18.8%, 13.3%, and 12.5%). In contrast, with a 2-day delay in amputation, the corresponding metastasis rates were 6.7%, 11.8%, and 40%, respectively. Animal survival rate was higher and CTL activity was enhanced in the HIFU treatment groups. Altogether, our results suggest that HIFU treatment does not increase the risk of distant metastasis. Instead, HIFU treatment can elicit an anti-tumor immune response that may be harnessed to improve the overall effectiveness and quality of cancer therapy.

Journal Article

IVIS, B16-F10-luc-G5, B16F10-luc-G5, B16-F10-luc, B16F10-luc

The incidence of malignant melanoma is rising more rapidly than that of any other cancer in the United States. The melanocortin 1 receptor (MC1R) is overexpressed in most human melanoma metastases, thus making it a promising target for imaging and therapy of melanomas. We have previously reported the development of a peptidomimetic ligand with high specificity and affinity for MC1R. Here, we have conjugated near-infrared fluorescent dyes to the C-terminus of this ligand via lysine-mercaptopropionic acid linkers to generate MC1R specific optical probes (MC1RL-800, 0.4 nM K(i); and MC1RL-Cy5, 0.3 nM K(i)). Internalization of the imaging probe was studied in vitro by fluorescence microscopy using engineered A375/MC1R cells and B16F10 cells with endogenous MC1R expression. The in vivo tumor targeting of MC1RL-800 was evaluated by intravenous injection of probe into nude mice bearing bilateral subcutaneous A375 xenograft tumors with low MC1R expression and engineered A375/MC1R tumors with high receptor expression. Melanotic B16F10 xenografts were also studied. Fluorescence imaging showed that the agent has higher uptake values in tumors with high expression compared to low (p < 0.05), demonstrating the effect of expression levels on image contrast-to-noise. In addition, tumor uptake was significantly blocked by coinjection of excess NDP-alpha-MSH peptide (p < 0.05). In conclusion, the MC1R-specific imaging probe developed in this study displays excellent potential for the intraoperative detection of regional node involvement and for margin detection during melanoma metastasis resection.

Journal Article

in vivo labelling; breast cancer; in vivo imaging

Bioorthogonal tetrazine cycloadditions have been applied to live cell labeling. Tetrazines react irreversibly with the strained dienophile norbornene forming dihydropyrazine products and dinitrogen. The reaction is high yielding, selective, and fast in aqueous media. Her2/neu receptors on live human breast cancer cells were targeted with a monoclonal antibody modified with a norbornene. Tetrazines conjugated to a near-infrared fluorochrome selectively and rapidly label the pretargeted antibody in the presence of serum. These findings indicate that this chemistry is suitable for in vitro labeling experiments, and suggests that it may prove a useful strategy for in vivo pretargeted imaging under numerous modalities.