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.

Download full-text


Available from: Hao Wei, Mar 20, 2015
1 Follower
48 Reads
  • Source
    • "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. "
    [Show abstract] [Hide abstract]
    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
  • Source
    • "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. "
    [Show abstract] [Hide abstract]
    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
  • Source
    • "Serum ceruloplasmin was measured based on its ferroxidase activity as described [18] "
    [Show abstract] [Hide abstract]
    ABSTRACT: Endothelial activation, which is characterized by upregulation of cellular adhesion molecules and pro-inflammatory chemokines and cytokines, and consequent monocyte recruitment to the arterial intima are etiologic factors in atherosclerosis. Redox-active transition metal ions, such as copper and iron, may play an important role in endothelial activation by stimulating redox-sensitive cell signaling pathways. We have shown previously that copper chelation by tetrathiomolybdate (TTM) inhibits LPS-induced acute inflammatory responses in vivo. Here, we investigated whether TTM can inhibit atherosclerotic lesion development in apolipoprotein E-deficient (apoE-/-) mice. We found that 10-week treatment of apoE-/- mice with TTM (33-66 ppm in the diet) reduced serum levels of the copper-containing protein, ceruloplasmin, by 47%, and serum iron by 26%. Tissue levels of "bioavailable" copper, assessed by the copper-to-molybdenum ratio, decreased by 80% in aorta and heart, whereas iron levels of these tissues were not affected by TTM treatment. Furthermore, TTM significantly attenuated atherosclerotic lesion development in whole aorta by 25% and descending aorta by 45% compared to non-TTM treated apoE-/- mice. This anti-atherogenic effect of TTM was accompanied by several anti-inflammatory effects, i.e., significantly decreased serum levels of soluble vascular cell and intercellular adhesion molecules (VCAM-1 and ICAM-1); reduced aortic gene expression of VCAM-1, ICAM-1, monocyte chemotactic protein-1, and pro-inflammatory cytokines; and significantly less aortic accumulation of M1 type macrophages. In contrast, serum levels of oxidized LDL were not reduced by TTM. These data indicate that TTM inhibits atherosclerosis in apoE-/- mice by reducing bioavailable copper and vascular inflammation, not by altering iron homeostasis or reducing oxidative stress.
    Atherosclerosis 06/2012; 223(2):306-13. DOI:10.1016/j.atherosclerosis.2012.06.013 · 3.99 Impact Factor
Show more