Copper chelation by tetrathiomolybdate inhibits lipopolysaccharide-induced inflammatory responses in vivo

Linus Pauling Institute, Oregon State University, Corvallis, Oregon 97331, USA.
AJP Heart and Circulatory Physiology (Impact Factor: 3.84). 07/2011; 301(3):H712-20. DOI: 10.1152/ajpheart.01299.2010
Source: PubMed


Redox-active transition metal ions, such as iron and copper, may play an important role in vascular inflammation, which is an etiologic factor in atherosclerotic vascular diseases. In this study, we investigated whether tetrathiomolybdate (TTM), a highly specific copper chelator, can act as an anti-inflammatory agent, preventing lipopolysaccharide (LPS)-induced inflammatory responses in vivo. Female C57BL/6N mice were daily gavaged with TTM (30 mg/kg body wt) or vehicle control. After 3 wk, animals were injected intraperitoneally with 50 μg LPS or saline buffer and killed 3 h later. Treatment with TTM reduced serum ceruloplasmin activity by 43%, a surrogate marker of bioavailable copper, in the absence of detectable hepatotoxicity. The concentrations of both copper and molybdenum increased in various tissues, whereas the copper-to-molybdenum ratio decreased, consistent with reduced copper bioavailability. TTM treatment did not have a significant effect on superoxide dismutase activity in heart and liver. Furthermore, TTM significantly inhibited LPS-induced inflammatory gene transcription in aorta and heart, including vascular and intercellular adhesion molecule-1 (VCAM-1 and ICAM-1, respectively), monocyte chemotactic protein-1 (MCP-1), interleukin-6, and tumor necrosis factor (TNF)-α (ANOVA, P < 0.05); consistently, protein levels of VCAM-1, ICAM-1, and MCP-1 in heart were also significantly lower in TTM-treated animals. Similar inhibitory effects of TTM were observed on activation of nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) in heart and lungs. Finally, TTM significantly inhibited LPS-induced increases of serum levels of soluble ICAM-1, MCP-1, and TNF-α (ANOVA, P < 0.05). These data indicate that copper chelation with TTM inhibits LPS-induced inflammatory responses in aorta and other tissues of mice, most likely by inhibiting activation of the redox-sensitive transcription factors, NF-κB and AP-1. Therefore, copper appears to play an important role in vascular inflammation, and TTM may have value as an anti-inflammatory or anti-atherogenic agent.

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Available from: Hao Wei, Mar 20, 2015
    • "In contrast to the investigated antioxidants, the two copper chelators BCS and TTM [31] [72] completely protected astrocytes from copper-induced toxicity, both in the absence and in the presence of ascorbate, most likely by preventing copper internalization by astrocytes. This is consistent with the lowered copper uptake previously reported for BCS-treated astrocytes [18]. "
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    ABSTRACT: Copper is essential for several important cellular processes, but an excess of copper can also lead to oxidative damage. In brain, astrocytes are considered to play a pivotal role in the copper homeostasis and antioxidative defence. To investigate whether antioxidants and copper chelators can modulate the uptake and the toxicity of copper ions in brain astrocytes, we used primary astrocytes as cell culture model. These cells accumulated substantial amounts of copper during exposure to copper chloride. Copper accumulation was accompanied by a time- and concentration-dependent loss in cell viability, as demonstrated by a lowering in cellular MTT reduction capacity and by an increase in membrane permeability for propidium iodide. During incubations in the presence of the antioxidants ascorbate, trolox or ebselen, the specific cellular copper content and the toxicity in copper chloride-treated astrocyte cultures were strongly increased. In contrast, the presence of the copper chelators bathocuproine disulfonate or tetrathiomolybdate lowered the cellular copper accumulation and the copper-induced as well as the ascorbate-accelerated copper toxicity was fully prevented. These data suggest that predominantly the cellular content of copper determines copper-induced toxicity in brain astrocytes. Copyright © 2015 Elsevier GmbH. All rights reserved.
    Journal of Trace Elements in Medicine and Biology 10/2015; 32:168-76. DOI:10.1016/j.jtemb.2015.07.001 · 2.37 Impact Factor
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    • "These data are in agreement with an early study using a rabbit brain tumor model in which copper lowering reduced tumor vessel width, as well as the proliferative rate of tumor endothelia, to similar levels seen in healthy brain vessels [12]. Similarly, a recent study has shown that copper plays an important role in vascular inflammation, and that copper chelation with TM may have value as an anti-inflammatory or anti-atherogenic agent [26]. In those studies mice treated with TM demonstrated significant inhibition of lipopolysaccharide-induced inflammatory gene transcription and protein levels of VCAM-1, ICAM-1 and monocyte chemotactic protein-1 in the aorta and heart. "
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    ABSTRACT: Copper, an essential trace element acquired through nutrition, is an important co-factor for pro-angiogenic factors including vascular endothelial growth factor (VEGF). Decreasing bioavailable copper has been used as an anti-angiogenic and anti-cancer strategy with promising results. However, the role of copper and its potential as a therapy in mesothelioma is not yet well understood. Therefore, we monitored copper levels in progressing murine mesothelioma tumors and analyzed the effects of lowering bioavailable copper. Copper levels in tumors and organs were assayed using atomic absorption spectrophotometry. Mesothelioma tumors rapidly sequestered copper at early stages of development, the copper was then dispersed throughout growing tumor tissues. These data imply that copper uptake may play an important role in early tumor development. Lowering bioavailable copper using the copper chelators, penicillamine, trientine or tetrathiomolybdate, slowed in vivo mesothelioma growth but did not provide any cures similar to using cisplatin chemotherapy or anti-VEGF receptor antibody therapy. The impact of copper lowering on tumor blood vessels and tumor infiltrating T cells was measured using flow cytometry and confocal microscopy. Copper lowering was associated with reduced tumor vessel diameter, reduced endothelial cell proliferation (reduced Ki67 expression) and lower surface ICAM/CD54 expression implying reduced endothelial cell activation, in a process similar to endothelial normalization. Copper lowering was also associated with a CD4(+) T cell infiltrate. In conclusion, these data suggest copper lowering is a potentially useful anti-mesothelioma treatment strategy that slows tumor growth to provide a window of opportunity for inclusion of other treatment modalities to improve patient outcomes.
    PLoS ONE 08/2013; 8(8):e73684. DOI:10.1371/journal.pone.0073684 · 3.23 Impact Factor
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    • "Taken together, our results provide evidence that CTGF up-regulates MCP-1 in human synovial fibroblasts via the αvβ5 integrin, FAK, MEK, and ERK signaling pathway. Previous studies have demonstrated that NF-κB and AP-1 were two important transcription factors that play a crucial role in immune and inflammatory responses [45] [46] [47] [48]. The results of this study showed that NF-κB and AP-1 activation contributes to CTGF-induced MCP-1 production in synovial fibroblasts. "
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    ABSTRACT: Connective tissue growth factor (CTGF; also known as CCN2) is an inflammatory mediator, and shows elevated levels in regions of severe injury and inflammatory diseases. CTGF is abundantly expressed in osteoarthritis (OA). Migration and infiltration of mononuclear cells to inflammatory sites are playing important role during OA pathogenesis. Monocyte chemoattractant protein-1 (MCP-1/CCL2) is the key chemokine that regulates migration and infiltration of monocytes. However, the effect of CTGF on MCP-1 expression and monocyte migration are largely unknown. Our results showed that MCP-1 was highly expressed in OA synovial fibroblasts (OASFs) as compared to normal SFs. Directly apply OASFs with CTGF increased MCP-1 expression by concentration and time-dependent manner. CTGF mediated MCP-1 production was attenuated by αvβ5 integrin neutralized antibody. Pretreatment with focal adhesion kinase (FAK), MEK, AP-1, and NF-κB inhibitors also inhibited the potentiating action of CTGF. CTGF-mediated increase of NF-κB and AP-1 luciferase activity was inhibited by FAK, MEK, and ERK inhibitors or mutants. In vitro chemotaxis assay showed that OA synovial fluid and supernatants from CTGF treated OASFs increased migration of monocyte. In addition, CTGF-mediated migration was inhibited by the FAK and MEK inhibitor. Taken together, our results indicated that CTGF enhances the migration of monocyte cells by increasing MCP-1 expression through the αvβ5 integrin, FAK, MEK, ERK, and NF-κB/AP-1 signal transduction pathway.
    Biochimica et Biophysica Acta 12/2012; 1833(5). DOI:10.1016/j.bbamcr.2012.12.014 · 4.66 Impact Factor
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