Biomarkers metallothionein

Keywords Barbus graellsii, Biomarkers, Choline esterases, Cyprinus carpio, Daphnia magna, Dreissena polymorpha, EROD, Metallothionein, qRT-PCR, Xenobiotics... 

Amiard JC, Amiard-Triquet C, Barka S, Pellerin J, Rainbow PS (2006) Metallothioneins in aquatic invertebrates their role in metal detoxification and their use as biomarkers. Aquat Toxicol 76(2) 160-202... 

Lecoeur S, Videmann B, Bemy P (2004) Evaluation of metallothionein as a biomarker of single and combined Cd/Cu exposure in Dreissena polymorpha. Environ Res 94(2) 184—191... 

Cows and calves fed low-zinc diets of 25 mg Zn/kg ration showed a decrease in plasma zinc from 1.02 mg/L at start to 0.66 mg/L at day 90 cows fed 65 mg Zn/kg diet had a significantly elevated (1.5 mg Zn/L) plasma zinc level and increased blood urea and plasma proteins (Ram-achandra and Prasad 1989). Biomarkers used to identify zinc deficiency in bovines include zinc concentrations in plasma, unsaturated zinc-binding capacity, ratio of copper to zinc in plasma, and zinc concentrations in other blood factors indirect biomarkers include enzyme activities, red cell uptake, and metallothionein content in plasma and liver (Binnerts 1989). 

Rotchell, J.M., Clarke, K.R., Newton, L.C., Bird, D.J. (2001). Hepatic metallothionein as a biomarker for metal contamination age effects and seasonal variation in European flounders (Pleuronectes flesus) from the Severn estuary and Bristol Channel. Marine Environmental Research, 52 151-171. 

Any one of a series of physiological, biochemical, behavioural or metrics measurements reflecting an interaction between a living system (tissue, organ, cell, etc.) and an environmental agent, which may be chemical, physical or biological. For example, the induction of metallothionein, a heavy metal biomarker of defense, is activated in fish hepatic tissue exposed to metals such as cadmium or mercury. Volume 1(14), Volume 2(1,10). 

Geffard, A., C. Amiard-Triquet, J.-C. Amiard, and C. Mouneyrac. 2001. Temporal variations of metallothionein and metal concentrations in the digestive gland of oysters (Crassostrea gigas) from a clean and a metal-rich site. Biomarkers 6 91-107. 

Mouneyrac, C., J.C. Amiard, C. Amiard-Triquet, A. Cottier, P.S. Rainbow, and B.D. Smith. 2002. Partitioning of accumulated trace metals in the talitrid amphipod crustacean Orchestia gammarellus A cautionary tale on the use of metallothionein-like proteins as biomarkers. Aquat. Toxicol. 57 225-242. 

Another common biomarker for trace metal exposure is the metal-binding protein metallothionein, which regulates normal zinc and copper metabolism and provides a mechanism for metal detoxification. Changes in metallothionein activity provide a sensitive marker of trace metal exposure. 

In Chinese Cd-exposed workers it was demonstrated that those with a high ability to induce metallothionein suffered less tubular damage than those with a low ability to induce metallothionein in peripheral blood lymphocytes [159]. Similar observations were reported from a population group in China environmentally exposed to cadmium [160]. These observations give support for an important role of metallothionein induction in humans and that such induction in peripheral blood lymphocytes can be used as a biomarker of individual sensitivity to development of renal damage. 

In a detailed analysis of earthworm metallothioneins, Stiirzenbaum et al. (1998c) identified two complementary DNAs (cDNAs) encoding metallothio-nein-like proteins. Both isoforms were induced by copper and cadmium and also a number of mine site soils. This work for both snails and earthworms confirms that metallothioneins are inducible by metal exposure and are thus useful biomarkers of exposure. 

Berger, B., Dallinger, R. and Thomaser, A. (1995) Quantification of metallothionein as a biomarker for cadmium exposure in terrestrial gastropods. Environmental Toxicology and Chemistry, 14, 781-791. 

Dallinger, R., Berger, B., Gruber, C., Hunziker, P. and Sturzenbaum, S. (2000) Metallothioneins in terrestrial invertebrates structural aspects, biological significance and implications for their use as biomarkers. Cellular and Molecular Biology, 46, 331-346. 

Cosson, R.P. (2000) Bivalve metallothionein as a biomarker of aquatic ecosystem pollution by trace metals limits and perspectives. Cell. Mol. Biol., 46, 295-309. 

Effect. Several potential biomarkers for the effects of zinc have been identified. These include increased levels of serum amylases and lipase, indicative of pancreatic damage non-iron responsive anemia and decreased HDL cholesterol levels (Suber 1989). However, these biomarkers of effect are not specific for zinc. These biomarkers cannot be used for dosimetry. A potential biomarker of exposure for recent exposures to zinc is increased erythrocyte metallothionein concentrations (Grider et al. 1990). Further investigation of serum biomarkers of effect, particularly for chronic exposure, in zinc-exposed populations would be useful to determine whether exposed populations may be experiencing adverse health effects as the result of zinc exposures. 

Adverse effects of mercury to fishes, in addition to those listed on reproduction and growth, have been documented at water concentrations of 0.88-5.0 xg/L enzyme disruption in brook trout (Salvelinus fontinalis) embryos immersed for 17 days in solutions containing 0.88 ig/L, as methylmercury decreased rate of intestinal transport of glucose, fructose, glycine, and tryptophan in the murrel (Channa punctatus) at 3.0 (xg Hg +/L for 30 days altered blood chemistry in striped bass (Morone saxatilis) at 5.0 xg Hg +/L in 60 days and decreased respiration in striped bass 30 days post-exposure after immersion for 30-120 days in 5.0 xg Hg +/L. In large-mouth bass, elevated liver metallothioneins are indicative of elevated muscle mercury concentrations, suggesting that mercury-induced metallothioneins may be useful biomarkers of mercury exposure. 

While the most of metallothionein research has been carried out on mammals or vertebrates, there are only few studies focused on invertebrates. Application of invertebrates as a suitable model for detection and monitoring the metal pollution of the environment has been shown in several works [129-134]. MT was usually determined as a biomarker of contamination of aquatic environment by heavy metals. Connection between increased levels of metallothionein as a biomaiker in different fish tissues and environmental pollution has been published in many papers [73,76,93,135-142]. On the other hand, application of MT as a biomaiker of metal pollution has been shown for the other animal species too [25, 26, 102, 103, 143-152]. 

There are sensitive methods available for the quantification of tubular proteinuria in populations exposed to cadmium occupationally or environmentally. RBP, p2-M, al-microglobuhn (al-M, also called protein HC), metallothionein, and enzymes such as N-acetyl- p-D-glucosaminidase (NAG) in human urine are used as biomarkers of cadmium-induced effects [56-61]. However, the effects are not specific to cadmium exposure, but may also occur due to various renal diseases or nephrotoxic agents other than cadmium. 

Berthet, B Moimeyrac, C Pdez, T, and Amiard-Triquet, C. (2005) Metallothionein concentration in sponges (Spongia qfficinalitj as a biomarker of a metal contamination. Comp. Biochem. Physiol. 141C, 306-313. 

Pan, L. and Zhang, H. (2006) Metallothionein, antioxidant enzymes and DNA strand breaks as biomarkers of Cd exposure in a marine crab, Charybdisjaponica. Comp. Biochem. Physiol, 144C, 67—75. 

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