Copper and inflammation--a possible rationale for the pharmacological manipulation of inflammatory disorders

Glycyl-l-histidyl-l-lysine prevents copper- and zinc-induced protein aggregation and central nervous system cell death in vitro

Common features of neurodegenerative diseases are oxidative and inflammatory imbalances as well as the misfolding of proteins. An excess of free metal ions can be pathological and contribute to cell death, but only copper and zinc strongly promote protein aggregation. Herein we demonstrate that the endogenous copper-binding tripeptide glycyl-l-histidyl-l-lysine (GHK) has the ability to bind to and reduce copper redox activity and to prevent copper- and zinc-induced cell death in vitro. In addition, GHK prevents copper- and zinc-induced bovine serum albumin aggregation and reverses aggregation through resolubilizing the protein. We further demonstrate the enhanced toxicity of copper during inflammation and the ability of GHK to attenuate this toxicity. Finally, we investigated the effects of copper on enhancing paraquat toxicity and report a protective effect of GHK. We therefore conclude that GHK has potential as a cytoprotective compound with regard to copper and zinc toxicity, with positive effects on protein solubility and aggregation that warrant further investigation in the treatment of neurodegenerative diseases.

Copper infused fabric attenuates inflammation in macrophages

While inflammation is an important immune response for protection from infections, excessive or prolonged inflammation can lead to a variety of debilitating diseases including skin disease, diabetes, heart disease, stroke, autoimmune diseases and cancer. Inflammation is a graded response that is typically initiated when resident macrophages sense the presence of pathogens or damage in the tissue and produce inflammatory cytokines and chemokines to kill the pathogen, clear debris and dead tissue, and initiate tissue repair. Here we show that copper-infused fabrics can prevent inflammation by blocking the production of inflammatory cytokines from macrophages after being exposed to LPS, a component of bacterial cell wall. Mechanistically, we show that copper-infused fabrics can significantly reduce the NF-κB and IRF3 activation in LPS-stimulated macrophages. Given the importance of excessive inflammation in diabetes, we show that copper can reduce insulin resistance mediated by inflammatory cytokines in muscle cells. Our data show that copper infused fabrics may be useful to reduce excessive inflammation in macrophages and improve insulin sensitivity in skeletal muscles.

Do urinary metals associate with the homeostasis of inflammatory mediators? Results from the perspective of inflammatory signaling in middle-aged and older adults

OBJECTIVE

We aimed to investigate whether urinary metal mixtures are associated with the homeostasis of inflammatory mediators in middle-aged and older adults.

METHODS

A four-visit repeated-measures study was conducted with 98 middle-aged and older adults from five communities in Beijing, China. Only one person was lost to follow-up at the third visit. Ultimately, 391 observations were included in the analysis. The urinary concentrations of 10 metals were measured at each visit using inductively coupled plasma mass spectrometry (ICP-MS) with a limit of detection (LOD) ranging from 0.002 to 0.173 µg/L, and the detection rates were all above 84%. Similarly, 14 serum inflammatory mediators were measured using a Beckman Coulter analyzer and the Bio-Plex MAGPIX system. A linear mixed model (LMM), LMM with least absolute shrinkage and selection operator regularization (LMMLASSO), and Bayesian kernel machine regression (BKMR) were adopted to explore the effects of urinary metal mixtures on inflammatory mediators.

RESULTS

In LMM, a two-fold increase in urinary cesium (Cs) and chromium (Cr) was statistically associated with -35.22% (95% confidence interval [CI]: -53.17, -10.40) changes in interleukin 6 (IL-6) and -11.13% (95 %CI: -20.67, -0.44) in IL-8. Urinary copper (Cu) and selenium (Se) was statistically associated with IL-6 (88.10%, 95%CI: 34.92, 162.24) and tumor necrosis factor-alpha (TNF-α) (22.32%, 95%CI: 3.28, 44.12), respectively. Similar results were observed for the LMMLASSO and BKMR. Furthermore, Cr, Cs, Cu, and Se were significantly associated with other inflammatory regulatory network mediators. For example, urinary Cs was statistically associated with endothelin-1, and Cr was statistically associated with endothelin-1 and intercellular adhesion molecule 1 (ICAM-1). Finally, the interaction effects of Cu with various metals on inflammatory mediators were observed.

CONCLUSION

Our findings suggest that Cr, Cs, Cu, and Se may disrupt the homeostasis of inflammatory mediators, providing insight into the potential pathophysiological mechanisms of metal mixtures and chronic diseases.

Efficacy of topical interventions for temporomandibular disorders compared to placebo or control therapy: a systematic review with meta-analysis

This systematic review focused on the efficacy of topical products in reducing temporomandibular joint disorder (TMD)-associated pain, in comparison to placebo or control interventions. The EMBASE, Web of Science, Cochrane Library, and MEDLINE via PubMed databases were searched for randomized controlled trials (RCTs) using topical interventions in adults diagnosed with TMD. The pain intensity was the primary outcome, and other clinical findings were the secondary outcomes. The risk of bias was evaluated according to the Cochrane's handbook. The search up to February 7, 2020 identified a total of 496 unduplicated references. Nine RCTs with 355 adult patients diagnosed with TMD were included. The meta-analysis did not show a significant reduction in baseline pain intensity in the nonsteroidal anti-inflammatory drug (NSAIDs) group, when compared to the placebo group (P = 0.288). One study demonstrated a statistically significant pain score decrease for Theraflex-TMJ compared to placebo after 10 d of treatment (P = 0.003) and follow-up, 5 d after the last application (P = 0.027). Ping On reduced pain at 4 weeks of application (P < 0.001) but not after 7 d of application (P = 0.136). In one study, cannabidiol (CBD) significantly improved the pain intensity compared to placebo (P < 0.001). However, no differences were found with capsaicin in the two studies (P = 0.465). Evidence was of low quality because the studies were considered as having an unclear or a high risk of bias and a small number of studies were analyzed. The evidence is not sufficient to support the use of topical NSAIDs and capsaicin, and limited evidence was found for Threraflex-TMJ, bee venom, Ping On, and CBD, with only one study reporting for each. Additional studies are recommended to validate these results.

Copper-Based Metal-Organic Framework as a Controllable Nitric Oxide-Releasing Vehicle for Enhanced Diabetic Wound Healing

Chronic wounds are one of the most serious complications of diabetes mellitus. Even though utilizing nitric oxide (NO) as a gas medicine to repair diabetic wounds presents a promising strategy, controlling the NO release behavior in the affected area, which is vital for NO-based therapy, still remains a significant challenge. In this work, a copper-based metal-organic framework, namely, HKUST-1, has been introduced as a NO-loading vehicle, and a NO sustained release system with the core-shell structure has been designed through the electrospinning method. The results show that the NO is quantificationally and stably loaded in the HKUST-1 particles, and the NO-loaded HKUST-1 particles are well incorporated into the core layer of the coaxial nanofiber. Therefore, NO can be controllably released with an average release rate of 1.74 nmol L^-1 h^-1 for more than 14 days. Moreover, the additional copper ions released from the degradable HKUST-1 play a synergistic role with NO to promote endothelial cell growth and significantly improve the angiogenesis, collagen deposition as well as anti-inflammatory property in the wound bed, which eventually accelerate the diabetic wound healing. These results suggest that such a copper-based metal-organic framework material as a controllable NO-releasing vehicle is a highly efficient therapy for diabetic wounds.

Pilot Study of 64CuCl₂ for PET Imaging of Inflammation

Copper(II) ion (Cu²⁺) is the essential element for numerous pathophysiological processes in vivo. Copper transporter 1 (CTR1) is mainly responsible for maintaining Cu²⁺ accumulation in cells, which has been found to be over-expressed in inflammatory tissues. Therefore, we explored the potential application of ⁶⁴CuCl₂ for PET imaging of inflammation through targeting CTR1. The animal models of H₂O₂ induced muscle inflammation and lipopolysaccaharide induced lung inflammation were successfully established, then imaged by small animal PET (PET/CT) post-injection of ⁶⁴CuCl₂, and PET images were quantitatively analyzed. H&E and immunohistochemical (IHC) staining and western blot experiments were performed for evaluating CTR1 levels in the inflammatory and control tissues. Both inflammatory muscle and lungs can be clearly imaged by PET. PET image quantitative analysis revealed that the inflammatory muscle and lungs showed significantly higher ⁶⁴Cu accumulation than the controls, respectively (p < 0.05). Furthermore, IHC staining and western blot analysis demonstrated that compared with the controls, CTR1 expression was increased in both the inflammatory muscle and lungs, which was consistent with the levels of ⁶⁴Cu²⁺ accumulation in these tissues. ⁶⁴CuCl₂ can be used as a novel, simple, and highly promising PET tracer for CTR1 targeted imaging of inflammation.

Schiff base complexes of copper and zinc as potential anti-colitic compounds

The design, synthesis and activity of polymodal compounds for the treatment of inflammatory bowel disease are reported. The compounds, being based on a metal-Schiff base motif, are designed to degrade during intestinal transit to release the bioactive components in the gut. The compounds have been developed sequential with the biomodal compounds combining copper or zinc with a salicylaldehyde adduct. These compounds were tested in a formalin induced colonic inflammation model in BK:A mice. From these studies a trimodal compound based on a zinc Schiff base analogue of sulfasalazine was designed. This was tested against a trinitrobenzenesulfonic acid (TNB) induced colitic model in Wistar rats. The use of two models allows us to test our compounds in both an acute and a chronic model. The trimodal compound reported is observed to provide anticolitic properties in the chronic TNB induced colitis model commensurate with that of SASP. However, the design of trimodal compound still has the capacity for further development. This the platform reported may offer a route into compounds which can markedly outperform the anti-colitic properties of SASP.

Effect of a topical copper indomethacin gel on inflammatory parameters in a rat model of osteoarthritis

Objective

We aimed to investigate the effect of topical application of a Copper indomethacin (Cu-Indo) gel preparation on monosodium iodoacetate (MIA) induced arthritis of the knee joint of rats and to test our hypothesis that copper complex of indomethacin could be a more potent anti-inflammatory agent than its parent compound.

Methods

After induction of osteoarthritis by the intracapsular injection of 50 μL with 40 mg/mL MIA, we compared the anti-inflammatory efficacy and safety of a topical application of 1% indomethacin gel in a dose of 1 g/kg of the gel (equivalent to 10 mg/kg of the active substance) daily for 3 weeks versus three decremental dose levels of Cu-Indo gel: an equivalent dose, half the dose, and 25% of the dose of indomethacin. Anti-inflammatory efficacy was assessed in all treated groups by measurement of serum inflammatory cytokines: interleukin 6, interleukin 8, and tumor necrosis factor alpha; and by the weekly assessment of knee joint swelling. Joint mobility and motor coordination were also assessed once weekly by the accelerating rotarod apparatus; histopathological examination of affected joints was also performed. Safety of topical application of Cu-Indo (0.25, 0.5, and 1 g/kg) for up to 3 months to rats’ skin was determined by the estimation of a complete blood count, liver and kidney functions, and histopathologic examination for target tissues.

Results

Cu-Indo gel at lower doses was superior to or at least as effective as its parent substance, indomethacin, in most of the studied parameters of inflammation. The lowest tested dose of Cu-Indo, corresponding to 25% of the parent substance indomethacin, exhibited the highest efficacy in reducing the elevated serum-tested interleukins and in increasing the time of duration on the rotarod test, whereas its effect on reduction of edema and tumor necrosis factor alpha was comparable to that of the others. After 3 months of daily application, there were no notable changes in studied safety parameters with the lowest Cu-Indo dose, but the group treated with the higher dose showed a small but statistically significant increase in serum-unconjugated bilirubin and a slight decrease in hemoglobin levels, red blood cells, and platelet count, with normal indices denoting a slight hemolytic effect at the highest dose.

Conclusion

Cu-Indo gel has potent anti-inflammatory activity against joint inflammation in the MIA-treated rat model of osteoarthritis at doses of 0.25, 0.5, and 1 g/kg. The lowest studied dose was better on both safety and efficacy parameters.

Identification of biomarkers that distinguish chemical contaminants based on gene expression profiles

Background

High throughput transcriptomics profiles such as those generated using microarrays have been useful in identifying biomarkers for different classification and toxicity prediction purposes. Here, we investigated the use of microarrays to predict chemical toxicants and their possible mechanisms of action.

Results

In this study, in vitro cultures of primary rat hepatocytes were exposed to 105 chemicals and vehicle controls, representing 14 compound classes. We comprehensively compared various normalization of gene expression profiles, feature selection and classification algorithms for the classification of these 105 chemicals into14 compound classes. We found that normalization had little effect on the averaged classification accuracy. Two support vector machine (SVM) methods, LibSVM and sequential minimal optimization, had better classification performance than other methods. SVM recursive feature selection (SVM-RFE) had the highest overfitting rate when an independent dataset was used for a prediction. Therefore, we developed a new feature selection algorithm called gradient method that had a relatively high training classification as well as prediction accuracy with the lowest overfitting rate of the methods tested. Analysis of biomarkers that distinguished the 14 classes of compounds identified a group of genes principally involved in cell cycle function that were significantly downregulated by metal and inflammatory compounds, but were induced by anti-microbial, cancer related drugs, pesticides, and PXR mediators.

Conclusions

Our results indicate that using microarrays and a supervised machine learning approach to predict chemical toxicants, their potential toxicity and mechanisms of action is practical and efficient. Choosing the right feature and classification algorithms for this multiple category classification and prediction is critical.

Effects of copper and zinc on proteoglycan metabolism in articular cartilage

Co-Cultures of porcine articular cartilage and synovium or synovial conditioned medium were used as an in vitro model to mimic inflammatory events at the cartilage/synovial junction in degenerative joint disease. This model provides a useful tool to assess the anti-inflammatory and antiarthritic properties of pharmacological agents. In this study the effects of copper and zinc on (i) PG synthesis by cartilage and (ii) synovial-induced PG depletion have been investigated. Copper sulphate at a concentration of 0.01 mM did not stimulate PG synthesis significantly in cultured cartilage explants but completely abrogated the inhibitory effects of synovial tissue in co-culture experiments. This finding was supported by the histological demonstration of copper-dependent reversal of the PG depletion in cartilage exposed to synovial conditioned medium. Zinc sulphate at 0.01 mM had no effect on PG synthesis and was unable to protect cartilage against synovialinduced PG depletion. These results reveal possible mechanisms by which copper exerts its anti-inflammatory and anti-arthritic actions.

Wilson disease at a single cell level: intracellular copper trafficking activates compartment-specific responses in hepatocytes

Wilson disease (WD) is a severe hepato-neurologic disorder that affects primarily children and young adults. WD is caused by mutations in ATP7B and subsequent copper overload. However, copper levels alone do not predict severity of the disease. We demonstrate that temporal and spatial distribution of copper in hepatocytes may play an important role in WD pathology. High resolution synchrotron-based x-ray fluorescence imaging in situ indicates that copper does not continuously accumulate in Atp7b(-/-) hepatocytes, but reaches a limit at 90-300 fmol. The lack of further accumulation is associated with the loss of copper transporter Ctr1 from the plasma membrane and the appearance of copper-loaded lymphocytes and extracellular copper deposits. The WD progression is characterized by changes in subcellular copper localization and transcriptome remodeling. The synchrotron-based x-ray fluorescence imaging and mRNA profiling both point to the key role of nucleus in the initial response to copper overload and suggest time-dependent sequestration of copper in deposits as a protective mechanism. The metabolic pathways, up-regulated in response to copper, show compartmentalization that parallels changes in subcellular copper concentration. In contrast, significant down-regulation of lipid metabolism is observed at all stages of WD irrespective of copper distribution. These observations suggest new stage-specific as well as general biomarkers for WD. The model for the dynamic role of copper in WD is proposed.

Use of Theraflex-TMJ topical cream for the treatment of temporomandibular joint and muscle pain

This randomized, double-blind study was designed to evaluate the effectiveness of the topical cream Theraflex-TMJ (NaBob/Rx, San Mateo, CA) in patients with masseter muscle pain and temporomandibular joint (TMJ) pain. Fifty-two subjects (5 males and 47 females) were instructed to apply a cream over the afflicted masseter muscle(s) or over the jaw joint(s) twice daily for two weeks. Theraflex-TMJ cream was used by the experimental group, while a placebo cream was used by the control group. The means of pain ratings were calculated prior to the application of the cream (baseline), after ten days of tx (period 1), and 15 days of tx (period 2) days of treatment and five days after stopping the treatment (follow-up). There was a significant decrease in reported pain levels from baseline in the experimental group for period 1 (p < 0.01), period 2 (p < 0.001), and follow-up (p < 0.01). For the control group, no significant differences were found between the different time periods (p > 0.05). There was evidence of minor side effects such as skin irritation and/or burning on the site of the application in two subjects in the experimental as well as two subjects in the control groups. The data strongly suggest that Theraflex-TMJ topical cream is safe and effective for reducing pain in the masseter muscle and the temporomandibular joint.

Copper hypersensitivity: dermatologic aspects--an overview

Reports of immune hypersensitivity reactions of both the immediate and the delayed type following cutaneous or systemic exposure to copper are reviewed here in an endeavor to draw a comprehensive profile of the immunogenic potential of that metal and its compounds. The immunotoxic potential of the metal is also briefly reviewed. In principle, as noted for other transition metals, the electropositive copper ion is potentially immunogenic because of its ability to diffuse through biological membranes, forming complexes when in contact with tissue protein. Based on the results of the predictive guinea pig test and the local lymph node assay (LLNA), copper has a low sensitization potential. Reports of immune reactions to copper include immunologic contact urticaria (ICU), allergic contact dermatitis (ACD), systemic allergic reactions (SAR) and contact stomatitis (STO), but considering the widespread use of copper intrauterine devices (IUDs) and the importance of copper in coinage, items of personal adornment and industry, unambiguous reports of sensitization to the metal are extremely rare, and even fewer are the cases that appear clinically relevant. Most reports of immune reactions to copper describe systemic exposure as a cause--predominantly to intrauterine devices and to prosthetic materials in dentistry--implicitly excluding the induction of hypersensitivity from contact with the skin as a risk factor.

Copper and zinc intake and serum levels in patients with juvenile rheumatoid arthritis

OBJECTIVE

To evaluate the copper and zinc intake and serum levels in patients with juvenile rheumatoid arthritis (JRA), considering the pauci and polyarticular types, the disease activity and duration, the number of inflamed joints and the use of corticosteroids therapy.

DESIGN

Cross-sectional study with control group.

SETTING

Outpatients of the pediatric rheumatology public health clinic, of the Universidade Federal de São Paulo/Escola Paulista de Medicina, Brazil.

SUBJECTS

Forty-one patients with JRA were evaluated and 23 patients' brothers, as a control group.

INTERVENTIONS

Copper and zinc intake evaluation by Food Register method. Copper and zinc serum levels by atomic absorption spectrophotometry.

RESULTS

The disease activity did not determine difference in copper (P=0.624) and zinc (P=0.705) intake, being predominantly below the Recommended Dietary Allowances. The serum copper in relation to control was statistically greater (P=0.018), showing that the number of inflamed joints is statistically significantly related with its variation (P=0.001). The serum zinc was not different either in relation to control (P=0.940) or to the disease characteristics.

CONCLUSIONS

The evaluation of copper intake seems to be of fundamental importance. It may influence the efficiency of the organic serum response. More research is needed to indicate, with security, adequate zinc intake.

Immunochemical and enzymatic study of ceruloplasmin in rheumatoid arthritis

Forty adult patients (30 women and 10 men) with rheumatoid arthritis (RA), treated with nonsteroidal anti-inflammatory drugs, were studied. Serum levels of immunoreactive ceruloplasmin, oxidase activity of the ceruloplasmin and total copper, as well as the specific oxidase activity (enzyme activity per unit of mass) and the copper/immunoreactive ceruloplasmin relationship were significantly higher in the group of patients than in the healthy control group (p < 0.001). However, no significant difference was found for the concentration of non-ceruloplasmin copper between both groups. A statistically significant negative correlation was obtained for the concentration of serum thiobarbituric acid-reacting substances with the immunoreactive ceruloplasmin and its oxidase activity in the group of patients (p < 0.005). These results suggest that in RA increases of serum copper are produced at the expense of the fraction linked to the ceruloplasmin, diminishing the proportion of apoceruloplasmin and other forms poor in copper. Although the increase in the serum concentration of ceruloplasmin might offer an additional safeguard against oxidative stress. it does not appear to have a beneficial effect upon the activity of the illness as evaluated by means the biological inflammation markers C-reactive protein, erythrocyte sedimentation rate and sialic acid.

Copper deficiency and cardiovascular disease: role of peroxidation, glycation, and nitration

Dietary copper deficiency causes a variety of cardiovascular deficits. Systemic effects include high blood pressure, enhancement of inflammation, anemia, reduced blood clotting, and possibly arteriosclerosis. Effects on specific organs or tissues include weakened structural integrity of the heart and blood vessels, impairment of energy use by the heart, reduced ability of the heart to contract, altered ability of blood vessels to control their diameter and grow, and altered structure and function of circulating blood cells. In some instances, the cause of a defect can be directly attributed to reduced activity of a specific copper-dependent enzyme. However, three nonspecific mechanisms of damage have been implicated in cardiovascular defects of copper deficiency. They are peroxidation, the interaction of oxygen-derived free radicals with lipids and proteins (possibly DNA); glycation, the nonenzymatic glycosylation of proteins; and nitration, the interaction of nitric oxide and its metabolites with peptides and proteins. Though independently these mechanisms present great potential for damage, the possibility that they may interact presents an added reason for concern. Furthermore, the fact that at least two of these mechanisms are associated with diabetes and aging suggests that copper deficiency may exacerbate deficits associated with these two conditions.Key words: copper, heart, circulation, peroxidation, glycation, nitric oxide.

Copper--ligand interactions and the physiological free radical processes. Part 3. Influence of histidine, salicylic acid and anthranilic acid on copper-driven Fenton chemistry in vitro

With a view to the possible use of copper(II)-*OH inactivating ligand (OIL) complexes as regulators of inflammation, the reactivity of the copper(II)-ascorbate system with hydrogen peroxide has been investigated in the presence of three key substances: histidine (the main copper(II) low molecular mass ligand in extracellular fluid), salicylic acid (the well-known nonsteroidal antiinflammatory drug, previously shown to be potentiated by copper(II) in animal models of inflammation), and anthranilic acid (an inactive substance by itself, known to be activated by copper(II) in the same models) at physiological pH (7.4) and inflammatory pH (5.5). Such substances may affect the amount of TBARS detected in solution following copper-mediated Fenton-like reactions through three distinct mechanisms: (i) by decreasing the Cu(II)/Cu(I) redox potential, i.e. at the expense of *OH radical production, (ii) by scavenging *OH radicals in the body of the solution, and/or (iii) by acting as a true OIL, i.e. at the expense of *OH detection. Redox potential measurements of initial solutions have been performed in parallel to TBARS determinations to help discriminate between different ligand influences. Computer-aided speciation has been used to understand the role of copper(II) distribution on the ligand effects characterised. Contrary to previous interpretations, histidine has been found to mainly affect *OH production by lowering the redox potential of the Cu(II)/Cu(I) couple. Salicylate, which has no effect on *OH production, has been confirmed to mainly scavenge *OH radicals in the body of the solution. Anthranilate, which both increases *OH production and decreases *OH detection, behaves as a potential OIL. These results tend to confirm our previous hypothesis that copper potentiation of antiinflammatory substances is indirect, i.e. independent of any interaction between metal and drug, whereas copper activation of substances that are inactive by themselves results from specific metal-substance interactions taking place at inflammatory sites.

Cardiovascular effects of dietary copper deficiency

Dietary copper deficiency may impair cardiovascular health by contributing to high blood pressure, enhancement of inflammation, anemia, reduced blood clotting and arteriosclerosis. The purpose of this review is to compile information on the numerous changes of the heart, blood and blood vessels that may contribute to these cardiovascular defects. These alterations include weakened structural integrity of the heart and blood vessels, impairment of the use of energy by the heart, reduced ability of the heart to contract, altered ability of blood vessels to control their diameter and to grow, and altered structure and function of circulating blood cells. The fundamental causes of these changes rest largely on reduced effectiveness of enzymes that depend on copper for their activity.

Dietary copper in the physiology of the microcirculation

Dietary copper has long been known to be essential for cardiovascular homeostasis. However, the role of copper and cuproenzymes in the normal control of vascular physiology is not well understood. Most studies in the cardiovascular system have focused on copper deficiency-induced defects in the heart or large vessels. Recently, attention has also focused on the effects of copper deficiency in the microcirculation or the small blood vessels that control blood flow, nutrient and waste exchange, and peripheral vascular resistance. Studies in the microcirculation demonstrate that copper is important in mechanisms of macromolecular leakage, platelet-endothelial interactions and vascular smooth muscle reactivity. There is a significantly greater leakage of proteins from postcapillary venules in copper-deficient rats in response to mast cell-released histamine. This response appears to be the result of increased numbers of mast cells and thereby increased available histamine. Copper deficiency also causes an inhibition of in vivo thrombogenesis, which appears to be related to an inhibition of platelet adhesion. Subsequent studies have demonstrated that this is probably caused by a diminished concentration of the adhesion molecule von Willebrand factor. Nitric oxide (NO)-mediated arteriole vasodilation is also compromised in copper-deficient rats. This functional deficit to NO can be reversed by the addition of Cu, Zn-superoxide dismutase (SOD), suggesting that degradation of NO by superoxide anion occurs during copper deprivation. These observations demonstrate that dietary copper is necessary for several microvascular control mechanisms affecting inflammation, microhemostasis and regulation of peripheral blood flow.

Copper-induced inflammatory reactions of rat carotid arteries mimic restenosis/arteriosclerosis-like neointima formation

The pathogenesis of arteriosclerosis and of restenosis after angioplasty is linked with an inflammatory and fibroproliferative response of the arterial tissue. We have induced a non-infectious inflammation by implanting a silicon-copper cuff around rat carotid arteries. The copper ions released from the oxidized copper initiate and mimic all morphological features of post-angioplasty restenotic and arteriosclerotic lesions. The copper-induced lesions were analyzed by electron and light microscopy, immunohistochemical methods and quantified by morphometry. During the first phase of copper-induced tissue reaction (3 days), macrophages and polymorphonuclear leucocytes invaded through the endothelium, accumulated in the subendothelial space and triggered the proliferation of smooth muscle cells which then migrated from the tunica media through the lamina elastica interna into the intima. Within 3 weeks, the accumulated smooth muscle cells, macrophages, leucocytes and newly synthesized extracellular matrix formed a circular mostly eccentric fibrotic thickening that narrows the vessel lumen by 30-40%. The accompanying structural disorganization of the medial layer led to focal rupture and aneurysm-like dilatation of the vessel wall in 3 of 11 animals between day 20 and 43. The neointima progressively increased in thickness over time leading to corresponding reduction of the vessel lumen. The carotid arteries of control animals and animals treated with copper-free silicon cuffs showed no abnormal pathological appearance. Our results show that inflammation-inducing agents can contribute to and simulate restenosis- and arteriosclerosis-like lesions and that the copper-cuff model may be useful in the exploration of new approaches to intervention.

The role of the mast cell in acute inflammatory responses of copper-deficient rats

Macromolecular leakage associated with mast cell degranulation was studied in the cremaster muscle microcirculation of copper-deficient rats. Male Sprague-Dawley rats were fed a purified diet either adequate for copper (6 micrograms copper/gram diet) or deficient (no added copper) 4 weeks prior to experimentation. The rats were anesthetized and the cremasters (with nerve and blood supply intact) were spread in a tissue bath filled with Kreb's solution. In vivo television microscopy was used to observe the microcirculation. Intravascular fluorescein isothiocyanate conjugated to bovine serum albumin was injected and interstitial fluorescent emission intensity was used as an index of macromolecular leakage. Topical administration of the mast cell degranulator compound 48/80 (1.0 and 10.0 micrograms/ml) induced a significantly greater macromolecular leakage in the copper-deficient animals. The compound 48/80 leakage was blocked in both groups of rats by pretreatment with diphenhydramine which is a histamine H1 receptor blocker. Topical administration of the inflammatory mediators histamine, serotonin, and bradykinin all induced macromolecular leakage which was not significantly different between groups. These results suggest that copper deficiency increases macromolecular leakage associated with mast cell degranulation by a primary effect on the mast cell rather than on the endothelium.

Copper and zinc body levels in inflammation: an overview of the data obtained from animal and human studies

The development of acute and chronic inflammatory processes induces, in the laboratory animal, a net accumulation of both copper and zinc in many body compartments, the inflamed area included. In rheumatoid arthritis, as well as in animal models, only plasma zinc concentration seems to be significantly correlated with disease severity, while the increase in total plasma copper could be described as an "all or nothing" phenomenon. Moreover, in rheumatoid arthritis, it appears that the disease develops and progresses without being linked to either copper or zinc deficiency conditions. Thus, it seems reasonable to suggest that a rationale for the use of copper and/or zinc in the treatment of inflammatory disorders can only be drawn from the intrinsic pharmacological properties of such trace elements, rather than from the need for their repletion.

Is copper pro- or anti-inflammatory? A reconciling view and a novel approach for the use of copper in the control of inflammation

The anti-inflammatory role of copper is well-known although still largely unexplained. On the other hand, the capacity of copper to induce the formation of damaging .OH radicals in vivo is no longer debated. These two aspects of the physiological activity of copper have been considered to be paradoxical. Arguments developed here show that they may actually derive from a single chemical process, the type of physiological effect observed depending on the ligand bound to the copper ions involved in Fenton chemistry. Both iron and copper are Fenton catalysts. Given its intrinsic coordination properties, however, copper induces more site-specific .OH damage to the ligands bound to it. It, therefore, appears that copper complexes with specific .OH-inactivating ligands (OILs) can be used as "lures" for the Fenton reaction, .OH radicals preferentially formed on these being immediately inactivated. The hypothesis is thus put forward here that copper-OIL complexes acting as effective Fenton catalysts are potential "catalase-like" anti-inflammatory drugs.

Skin inflammation: reactive oxygen species and the role of iron

Superoxide and hydrogen peroxide are reactive oxygen species (ROS) primarily produced by phagocytic cells as a consequence of the process of phagocytosis. This defensive role, may, however, become one of attack when production of ROS is excessive and overwhelms cellular scavenging systems. This happens in situations such as acute inflammation and results in host cell membrane damage, which is particularly prevalent in the presence of transition metal catalysts such as iron and copper. The skin is uniquely vulnerable to this attack being rich in polyunsaturated fatty acids and exposed to high oxygen tensions and ultraviolet light, both of which promote production of ROS. Additionally, the respiratory burst of infiltrating polymorphonuclear leukocytes and macrophages in inflamed skin will produce high local levels of superoxide that can release "catalytic iron" from storage proteins such as ferritin. The role of iron and ROS in the pathogenesis of inflammatory skin disease is discussed as is the possibility of novel therapeutic strategies based on their removal.

Synthesis, characterization, and biological screening of a copper flurbiprofen complex with anti-inflammatory effects

The flurbiprofen complex of copper(II) was prepared and characterized by IR, UV-VIS and EPR Spectroscopy, magnetic susceptibility, and thermogravimetric analysis. The compound was tested for in vivo anti-inflammatory and analgesic activities in rats. The inhibitory effect on carrageenin-induced paws inflammation and analgesic effect of copper flurbiprofen complex were similar to those of free flurbiprofen. However, the copper complex produced less gastric irritation than the parent drug.

CuSO4 as an inhibitor of B cell proliferation

In the course of investigating the mechanisms of the in vitro immunosuppressive effect of D-penicillamine in the presence of copper ion with murine spleen cells, we observed that copper ion, by itself, exhibited a strong immunosuppressive effect at a low concentration. Namely, the addition of CuSO4 at a concentration of 0.1 to 2 microM markedly inhibited the development of SRBC-specific plaque forming cells (PFC) without causing cytotoxicity. CuSO4, at the same concentration range, suppressed the lipopolysaccharide (LPS)-induced proliferative response, but not the response induced by concanavalin A (Con A). The suppressive effect of CuSO4 on the antibody production was reversed by 500 U/ml of catalase, but that on the LPS-induced proliferative response was not. CuSO4 also substantially suppressed the pokeweed mitogen-induced proliferative response. These findings suggest that CuSO4 acts as an inhibitor of B cell proliferation and, through this effect, markedly inhibits the antibody production in murine spleen cells.

Effects of copper aspirinate and aspirin on tissue copper, zinc, and iron concentrations following chronic oral treatment in the adjuvant arthritic rat

Concentrations of copper, zinc, and iron were analyzed and compared in a number of tissues of adjuvant arthritic rats following 22 d of chronic treatment (per os) with either vehicle, aspirin or copper aspirinate, at doses of 100 mg/kg, 200 mg/kg, or 400 mg/kg. Such chronic treatment resulted in a negative balance in copper, zinc, and iron in many tissues. Among the tissues examined, liver and kidney exhibited the greatest changes in metal concentrations; brain and skeletal muscle exhibited the least. Arthritis-induced changes in the concentrations of all three metals in the liver were reversed upon treatment with aspirin. Treatment with copper aspirinate, on the other hand, resulted in an extremely high accumulation of copper in the liver. Arthritis-induced changes in copper, zinc, and iron concentrations in the pancreas and copper concentration in the plasma were generally not reversed upon treatment with either aspirin or copper aspirinate. Among the three metals examined, the degree of change observed as a result of drug treatments was greatest for iron and least for zinc. Finally, it appeared that the effects of aspirin and copper aspirinate on tissue metal concentrations were independent of the antiarthritic effects of these compounds.

The pharmacologic activity of complexes and mixtures with copper and salicylates or aminopyrine following oral dosing in rats

Cu(II) complexes with salicylates or aminopyrine were administered to rats with local inflammation (acute paw oedema elicited with carrageenan) to determine their anti-inflammatory activity and ulcerogenic effects following oral administration. The complexes were more effective than the parent ligands or appropriate mixtures of these ligands with Cu(II) as anti-inflammatory agents. All complexes indicated low ulcerogenity. The differences in pharmacologic activity between the complexes and mixtures in question are discussed.

Changes in zinc, copper and selenium status during adjuvant-induced arthritis in rats

Trace elements such as zinc, copper and selenium are involved in the pathogenesis of inflammatory diseases. In order to obtain more information about the overall movements of these minerals during the evolution of an experimental chronic inflammatory process, trace element levels were determined in five body compartments of the rat at several time intervals after induction of adjuvant arthritis. Rapid and significant changes in plasma zinc and copper levels and in liver zinc levels were observed. These modifications occurred as early as those in biochemical parameters of inflammation such as serum fibrinogen and ceruloplasmin, and preceded the appearance of any clinical symptom of the disease. Inverse correlations were found between plasma zinc levels and these two biochemical indices. Other modifications in trace element levels were observed two weeks after disease induction, the most important being a considerable increase in liver copper levels. Although food intake of affected animals decreased with the progression of the disease, there was no evidence of depletion in zinc and copper levels over the study period. A redistribution of body zinc between different biological compartments (mainly plasma and liver) occurred simultaneously with an accumulation of copper in several organs. The decreasing selenium status of animals was not clearly related to the inflammatory process.

Copper and zinc status in adjuvant-arthritic rat: studies on blood, liver, kidneys, spleen and inflamed paws

The status of copper and zinc in plasma, blood cells, kidneys, spleen and hind paws was evaluated in tail-injected adjuvant-arthritic rats, during both the asymptomatic (3 and 7 days after the inoculum) and symptomatic (14, 21 and 30 days after the inoculum) phases of the experimental disease. During the symptomatic phase, inflamed rats were studied divided into two groups on the basis of their arthritic scores (low-score L.S. and high-score H.S. arthritic rats). Copper (both in concentration and total amount) was found significantly increased in plasma, blood cells, liver, spleen and arthritic paws, whereas, in the kidneys, it was found to be lower than normal. Zinc was found to be remarkably increased in the liver. In blood, zinc was found to be decreased in plasma, but almost unchanged in the cellular fraction. Zinc total amount (but not concentration) was increased in the spleen, most likely because of a significant increase in spleen weight. As previously described in the case of acute inflammation, zinc concentration was found to be significantly decreased in arthritic paws, whereas the total amount of the metal present in these inflamed tissues was higher than normal. The status of copper and zinc may well differentiate L.S. from H.S. arthritic rats, especially during the latest phase of the experimental disease, and particularly because of a normalization of the considered parameters in the low-score group. Many of the changes observed in the status of both metals were seen prior the appearance of arthritis. The overall accumulation of copper and zinc which is induced in rat by the development of adjuvant arthritis, is suggested to further sustain the hypothesis of increased body requirements for both metals during inflammation.

Tropical fish medicine. Copper treatments. Uses and precautions

Copper is an old but effective treatment for fish diseases. It is now primarily used to treat acute infestations of parasites such as Amyloodinium and Cryptocaryon. Many fish are sensitive to copper and may become intoxicated at concentrations required to control pathogens. Copper concentrations in treatment tanks must be measured frequently to ensure that levels are therapeutic but not toxic. A knowledge of the solution chemistry of copper is essential in understanding how to avoid unexpected changes in copper concentrations. Factors such as pH, salinity, decorative materials, nature of the filter bed, and the type of therapeutic agent used for treatment must be considered.

Copper and zinc status during acute inflammation: studies on blood, liver and kidneys metal levels in normal and inflamed rats

The concentrations of copper and zinc in plasma, blood cells, liver and kidneys were determined in a study performed on normal female rats, and in female rats with carrageenan induced pleurisy. In the normal rat, the total amount of both metals increases, from 51 to 79 days of age, in all the compartments examined. This increase was mostly, and in some case exclusively, dependent upon the growth of the animal, although high individual and day to day variations in both copper and zinc values were observed in all the compartments studied. In the blood of inflamed rats a statistically significant increase in copper was measured during the crucial hours of the experiment (i.e. from 6 to 72 h); over 90% of the increase found was attributable to variations in plasma copper concentration values. In the liver of inflamed rats a statistically significant increase in zinc was measured at 6, 22 and 48 h after the carrageenan injection. The induction of the acute non-infective inflammatory process did not cause quantitative changes of both copper and zinc in all the other compartments considered in the present study. These results seem to suggest that, during acute inflammation, the organism increases its requirement for copper and zinc, and that this demand is fulfilled by enhanced intestinal absorption and/or decreased intestinal excretion of both metals.

Copper and inflammation--a possible rationale for the pharmacological manipulation of inflammatory disorders

Acute and chronic inflammations are characterized, among other features, by changes in the metabolism of copper and by a widespread responsiveness to the therapy with copper-containing molecules. The exact map of inflammation-induced copper movements as well as the role played by the metal in the pathogenesis of inflammatory disorders are, however, far from being clear, and this is especially true in the case of chronic processes. Nevertheless the present knowledge suggests that the "copper approach' may provide a new way for coping with the problem of anti-inflammatory/anti-arthritic therapies. The administration of exogenous copper, and the in vivo manipulation of the endogenous metal levels are proposed as two possible therapeutic strategies, not necessarily mutually exclusive. For a better understanding of the value of such an approach, further research work is needed, especially to attain a more detailed know-how on the involved chemical forms, distribution and functions of copper in both normal as well as inflamed organisms.