Copper(II)(3,5-diisopropylsalicylate)2 accelerates recovery of B and T cell reactivity following irradiation

The immune system as a physiological indicator of marginal copper status?

Cu appears to have many important functional roles in the body that apparently relate, among others, to the maintenance of immune function, bone health and haemostasis. Some have suggested a role for long-term marginal Cu deficiency in the aetiology of a number of degenerative diseases. Accurate diagnosis of marginal Cu deficiency, however, has remained elusive despite an increased understanding of the biochemistry of Cu and its physiological roles in the body. Traditional markers of Cu status, such as serum Cu and caeruloplasmin protein concentrations are insensitive to subtle changes in Cu status. Cu-containing enzymes, such as Cu–Zn-superoxide dismutase, cytochromecoxidase and diamine oxidase, may be more reliable but evidence to date is not conclusive. Development of markers sensitive to marginal Cu status is essential before conclusions can be drawn concerning the risks of long-term intake of suboptimal dietary Cu. As Cu appears to be essential for maintenance of immune function, activities of specific immunological markers, altered in Cu deficiency, offer alternatives. This review evaluates a selection of immunological markers that could be considered potentially sensitive markers of marginal Cu status. The indices of immune function reviewed are neutrophil function, interleukin 2 production, blastogenic response to mitogens and lymphocyte subset phenotyping.

Wild-type bone marrow cells ameliorate the phenotype of SOD1-G93A ALS mice and contribute to CNS, heart and skeletal muscle tissues

Amyotrophic lateral sclerosis (ALS) is a progressive, lethal neurodegenerative disease without any effective therapy. To evaluate the potential of wild-type bone marrow (BM)-derived stem cells to modify the ALS phenotype, we generated BM chimeric Cu/Zn superoxide dismutase (SOD1) mice by transplantation of BM cells derived from mice expressing green fluorescent protein (GFP) in all tissues and from Thy1-YFP mice that express a spectral variant of GFP (yellow fluorescent protein) in neurons only. In the recipient cerebral cortex, we observed rare GFP+ and YFP+ neurons, which were probably generated by cell fusion, as demonstrated by fluorescence in situ hybridization (FISH) analysis, suggesting that this phenomenon is not limited to Purkinje cells. GFP-positive microglial cells were extensively present in both the brain and spinal cord of the affected animals. Completely differentiated and immature GFP+ myofibres were also present in the heart and skeletal muscles of SOD1 mice, confirming that BM cells can participate in striated muscle tissue regeneration. Moreover, wild-type BM chimeric SOD1 mice showed a significantly delayed disease onset and an increased life span, probably due to a positive 'non-neuronal environmental' effect rather than to neuronogenesis. This improvement in SOD1-G93A mouse survival is comparable with that previously obtained using some safer pharmacological agents. BM transplantation-related complications in humans preclude its clinical application for ALS treatment. However, our data suggest that further studies aimed at improving the degree of tissue chimerism by BM-derived cells may provide valuable insights into strategies to slow ALS progression.

Copper-ligand interactions and physiological free radical processes. Part 2. Influence of Cu2+ ions on Cu(+)-driven .OH generation and comparison with their effects on Fe(2+)-driven .OH production

In our search to establish a reference .OH production system with respect to which the reactivity of copper(II) complexes could then be tested, the influence of free Cu2+ ions on the Cu+/H2O2 reaction has been investigated. This influence depends on the CCu2+/CCu+ ratio. At low Cu2+ concentrations, .OH damage to various detector molecules decreases with increasing Cu2+ concentrations until CCu2+/CCu+ reaches unity. Above this value, .OH damage increases sharply until CCu2+/CCu+ becomes equal to 5 with salicylate and 2 with deoxyribose, ratios for which the protective effect of Cu2+ cancels. Finally, at higher concentrations, Cu2+ ions logically add their own .OH production to that normally expected from Cu+ ions. The possible origin of this unprecedented alternate effect has been discussed. The possible influence of Cu+ ions on the generation of .OH radicals by water gamma radiolysis has also been tested and, as already established for Cu2+ in a previous work, shown to be nonexistent. This definitely confirms that either form of ionised copper cannot scavenge .OH radicals in the absence of a ligand.

Inhaled isobutyl nitrite compromises T-dependent, but not T-independent, antibody induction

Habitual abuse of nitrite inhalants has been linked in epidemiological studies with seropositivity to human immunodeficiency virus and, separately, with Kaposi's sarcoma among AIDS patients. Mice exposed to isobutyl nitrite in an inhalation chamber for 45 min/day for 14 days had depressed IgM and IgG antibody responses. The inhibition was dose-dependent at 750-900 ppm, but antibody responses were increased at an intermediate (600 ppm) dose. Gender differences in immunotoxicity were not observed. Antibody responses to a T-independent antigen (DNP-ficoll) were not affected by the immunotoxic exposure, suggesting that B-cells were refractory to the toxic exposure. Toxic exposure to isobutyl nitrite did not selectively deplete a particular spleen cell population, but caused equivalent reductions of T-cells and B-cells. Finally, exposed mice remained immunocompromised for 3-5 days after terminating exposures. Normal immune responses returned by 5-7 days, suggesting that inhibition of cellular function was reversible.

Copper complexes stimulate hemopoiesis and lymphopoiesis

Copper(II)2(3,5-diisopropylsalicylate)4 [Cu(II)2(3,5-DIPS)4] is a synthetic copper complex with a variety of effects, including radiation recovery, anti-inflammatory, and accelerated wound healing activities. When C57BL/6 mice were injected subcutaneously with 80 mumol/kg Cu(II)2(3,5-DIPS)4 their spleens significantly enlarged. This splenomegally lasted for at least 3 weeks and was accompanied by increased myelopoiesis in the spleen. Bone marrow had no significant change in cellularity or myelopoiesis. The treatment with Cu(II)2(3,5-DIPS)4 had only minor effects on the ability of spleen cells to respond to mitogenic or antigenic stimulation. Cu(II)2(3,5-DIPS)4 did stimulate lymphopoiesis, since it accelerated the recovery of immune reactivity following exposure to 8 Gy whole body irradiation. Copper levels in the spleens and bone marrow of unirradiated mice treated with Cu(II)2(3,5-DIPS)4 were not significantly elevated 24 hr after treatment and copper levels were transiently reduced 7 days after treatment.