1. Use of zinc-copper metabolic interactions in the treatment of Wilson's disease
V Yuzbasiyan-Gurkan, G J Brewer, D Y Lee J Am Coll Nutr . 1990 Oct;9(5):487-91. doi: 10.1080/07315724.1990.10720405.
Zinc acetate is becoming a well-established therapy for the treatment of Wilson's disease. It is excellent for maintenance therapy and for the treatment of the presymptomatic patient. Current evidence suggests that it will also be excellent for the treatment of the pregnant patient. Zinc acts by inducing intestinal cell metallothionein, which binds copper with high affinity, blocking its absorption, and causing its excretion in the stool. We have shown that zinc, even in doses as low as 25 mg daily, negatively affects copper balance. Zinc in doses of 50 mg three times daily, with all doses separated from food, controls the abnormal positive copper balance, blocks uptake of orally administered 64Cu, controls urine and plasma copper, prevents the reaccumulation of hepatic copper, and prevents the development or progression of symptoms of copper toxicosis in Wilson's disease patients. Zinc acetate will probably be licensed in the near future for the treatment of Wilson's disease. We recommend that physicians use urine and plasma copper, and urine zinc, as primary monitoring tools. In contrast to the comfortable situation with maintenance therapy, the initial treatment of acutely ill Wilson's disease patients is not well worked out. Patients with neurological disease often get worse initially on penicillamine, and zinc acts more slowly than is ideal. We have initiated studies of tetrathiomolybdate for this purpose. Studies of biliary secretions of normal subjects suggest that they excrete regulatory (excess) copper packaged in a protease-resistant ceruloplasmin fragment. This fragment is missing in Wilson's disease bile. The gene for Wilson's disease is on chromosome 13, close to the retinoblastoma locus.(ABSTRACT TRUNCATED AT 250 WORDS)
2. Insights into acetate-mediated copper homeostasis and antioxidant defense in lentil under excessive copper stress
Lam-Son Phan Tran, Kien Huu Nguyen, Masayuki Fujita, Mirza Hasanuzzaman, Md Shahadat Hossain, Sayed Mohammad Mohsin, Ha Duc Chu, Cuong Duy Tran, Mostafa Abdelrahman, Yasuko Watanabe Environ Pollut . 2020 Mar;258:113544. doi: 10.1016/j.envpol.2019.113544.
Gradual contamination of agricultural land with copper (Cu), due to the indiscriminate uses of fungicides and pesticides, and the discharge of industrial waste to the environment, poses a high threat for soil degradation and consequently food crop production. In this study, we combined morphological, physiological and biochemical assays to investigate the mechanisms underlying acetate-mediated Cu toxicity tolerance in lentil. Results demonstrated that high dose of Cu (3.0 mM CuSO4. 5H2O) reduced seedling growth and chlorophyll content, while augmenting Cu contents in both roots and shoots, and increasing oxidative damage in lentil plants through disruption of the antioxidant defense. Principle component analysis clearly indicated that Cu accumulation and increased oxidative damage were the key factors for Cu toxicity in lentil seedlings. However, acetate pretreatment reduced Cu accumulation in roots and shoots, increased proline content and improved the responses of antioxidant defense (e.g. increased catalase and glutathione-S-transferase activities, and improved action of glutathione-ascorbate metabolic pathway). As a result, excess Cu-induced oxidative damage was reduced, and seedling growth was improved under Cu stress conditions, indicating the role of acetate in alleviating Cu toxicity in lentil seedlings. Taken together, exogenous acetate application reduced Cu accumulation in lentil roots and shoots and mitigated oxidative damage by activating the antioxidant defense, which were the major determinants for alleviating Cu toxicity in lentil seedlings. Our findings provide mechanistic insights into the protective roles of acetate in mitigating Cu toxicity in lentil, and suggest that application of acetate could be a novel and economical strategy for the management of heavy metal toxicity and accumulation in crops.
3. Increased carbon dioxide reduction to acetate in a microbial electrosynthesis reactor with a reduced graphene oxide-coated copper foam composite cathode
Adam C Stoot, Pier-Luc Tremblay, Marc Hvid Overgaard, Lulu Wan, Yiming Chen, Tian Zhang, Nabin Aryal Bioelectrochemistry . 2019 Aug;128:83-93. doi: 10.1016/j.bioelechem.2019.03.011.
Microbial electrosynthesis is a bioprocess where microbes reduce CO2into multicarbon chemicals with electrons derived from the cathode of a bioelectrochemical reactor. Developing a highly productive microbial electrosynthesis reactor requires excellent electrical connection between the electrochemical setup, the cathode, and the microbes. Copper is a highly conductive cathode material widely employed in electrochemical apparatuses. However, the antimicrobial properties of copper limit its usage for bioelectrochemistry. Here, biocompatible reduced graphene oxide coated on copper foam is synthesized as a cathode material for the microbial electrosynthesis of acetate from CO2. Dense and electroactive Sporomusa ovata biofilms form on the surface of reduced graphene oxide-coated copper foam electrodes while only scattered and damaged cells cover uncoated copper electrodes. Besides the formation of metabolically-active biofilms, acetate production rate from CO2is 21.3 and 43.5-fold higher with this novel composite cathode compared with an uncoated copper foam cathode and a reversed cathode made of reduced graphene oxide foam coated with copper, respectively. The results demonstrate that reduced graphene oxide can be employed as a biocompatible and conductive buffer between microbes and bactericidal electrode materials with excellent electrochemical property to enable highly performant microbial electrosynthesis.
