• 한국환경보건학회지
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• 제24권3호
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• pp.107-113
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• 1998

This study was performed to investigate the effects of chitin, chitosan and dithiocarbamate chitosan on the cadmium accumulation in liver and kidney of catfish. The experimental groups were divided into four independent groups which were one control group and three experimental groups by cadmium alone treatment or chitin, chitosan and dithiocarbamate chitosan which cadmium. in order to investigate the effects of chitin, chitosan and dithiocarbamate chitosan on the cadmium accumulation in liver and kidney of catfish, the cadmium concentration, the metallothionein level were measured. The results obtained were as follows: 1. The cadmium concentrations in liver and kidney of catfish in cadmium alone treatment group were similar to that of the chitin treatment group, but chitosan and dithiocarbamate chitosan treatment groups were significantly decreased. 2. The metallothionein levels in liver and kidney of catfish alone treatment group were similar to that of the chitin treatment group, but chitosan and dithiocarbamate chitosan treatment groups were significantly increased. In conclusion, this study revealed the effect of chitin, chitosan and dithiocarbamate chitosan against cadmium accumulation in liver and kidney of catfish. It exhibited the highest effect at dithiocarbamate chitosan treatment group.

• 한국환경성돌연변이발암원학회지
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• 제24권2호
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• pp.85-90
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• 2004

Nickel(II) compounds are carcinogenic metals which induce genotoxicity and oxidative stress through the generation of reactive oxygen species. In search of new molecular pathways toward understanding the molecular mechanism of nickel(II)-induced carcinogensis, we performed mRNA differential display analysis using total RNA extracted from nickel(II) acetate-treated normal rat kidney cells (NRK-52E). Cells were exposed for 3 days to 160 and 240 uM nickel(II) concentrations. cDNAs corresponding to mRNAs for which expression levels were altered by nickel(II) were isolated, sequenced, and followed by a GenBank Blast homology search. Specificity of differential expression of cDNAs was determined by RT-PCR and Western blot analysis. Two of them (SH3BGRL3 and FHIT) were down-regulated and one (metallothionein) was up-regulated by nickel(II) treatment. The expression of these mRNAs were nickel(II) concentration-dependent. The levels of FHIT and metallothionein proteins were also consistent with the results for mRNAs. Overall, although the fundamental questions related to function of these genes in nickel(II)-mediated carcinogenicity are not answered, our study suggests that they can be interesting candidates for studies of molecular mechanisms of nickel(II) carcinogenesis.

• Journal of Nutrition and Health
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• 제29권6호
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• pp.597-607
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• 1996

This study has been investigated the potenial of increased dietary cysteine to alter the effects of cadmium and lead on tissure and bone metal concentrations, excretion and tissue metallothionein(MT) concentrations. Fifty-four male rats of Sprgue-Dawley strain weighing 149$\pm$17g were divided into 9 groups according to body weight. Nine experimental diets with different cadmium (0ppm, 400ppm), lead(0ppm, 710ppm) and cysteine (0.06%, 0.45%, 0.90%) levels were given to rats for 30 days ; Food intake, weight gain, F.E.R, and weights of liver, kidney and femur were decreased in cadmium supplied groups than in cadmium free groups. Urinary and fecal cadmium excretions were increased and MT synthesis we induced in liver, kidney and small intestine in cadmium supplied groups. In lead supplied groups, weight gain and F.E.R were decreased. With cysteine supplementation in cadmium supplied groups, weight gain and F.E.R, and weights of liver, kidney and femur were increased. Cadmium excretion in feces and MT concentrations in liver and kidney were also increased with cysteine supplementation. In lead supplied groups, there was no significant increase in food intake, weight gain and F.E.R with cysteine supplementation. Lead excretion in feces was increased in cysteine supplemented groups. In conclusion, effect of cadmium administration was more toxic than lead adminstration. Cysteine alleviated cadmium and lead toxicity by increasing metallothionein concentration and fecal excretions of heavy metals. Especially, effect of cysteine supplementation was more effective in cadmium groups than in lead groups. Effect of cysteine supplementation was not different with level of cysteine supplementation in both cadmium and lead groups.

• Journal of Microbiology and Biotechnology
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• 제26권5호
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• pp.846-853
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• 2016

We displayed four types of Solanum nigrum metallothionein (SMT) for the first time on the surface of Saccharomyces cerevisiae using an α-agglutinin-based display system. The SMT genes were amplified by RT-PCR. The plasmid pYES2 was used to construct the expression vector. Transformed yeast strains were confirmed by PCR amplification and custom sequencing. Surface-expressed metallothioneins were indirectly indicated by the enhanced cadmium sorption capacity. Flame atomic absorption spectrophotometry was used to examine the concentration of Cd²⁺ in this study. The transformed yeast strains showed much higher resistance ability to Cd²⁺ compared with the control. Strikingly, their Cd²⁺ accumulation was almost twice as much as that of the wild-type yeast cells. Furthermore, surface-engineered yeast strains could effectively adsorb ultra-trace cadmium and accumulate Cd²⁺ under a wide range of pH levels, from 3 to 7, without disturbing the Cu²⁺ and Hg²⁺. Four types of surfaceengineered Saccharomyces cerevisiae strains were constructed and they could be used to purify Cd²⁺-contaminated water and adsorb ultra-trace cadmium effectively. The surface-engineered Saccharomyces cerevisiae strains would be useful tools for the bioremediation and biosorption of environmental cadmium contaminants.

• Ocean and Polar Research
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• 제23권4호
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• pp.337-345
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• 2001

A Cd-binding protein was identified in the renal cytosol of the Antarctic clam Laternula elliptica which naturally contains high concentrations of Cd. The Cd-binding protein showed similar characteristics of metallothionein (MT) in molecular weight (about 10-12 kDa) and low spectral absorbance at 280 nm with relatively high absorbance at 254nm. Results of immuno-histochemical staining suggested that the MT-like Cd-binding protein was mainly located in the epithelial cells of the kidney. The MT-like protein was a major ligand of cytosolic Cd as shown in the elution profiles of chromatography and may play an important role in Cd sequestration and accumulation in L. elliptica kidney. A considerable amount of Cd was also found to be associated with particulate fraction, indicating the sequestration to particulate fraction is as important as binding to the cytosolic MT-like protein in Cd accumulation in the kidney.

• Journal of Microbiology and Biotechnology
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• 제21권5호
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• pp.455-463
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• 2011

Metallothioneins are a class of small cysteine-rich proteins that have been associated with increased tolerance to metal and oxidative stresses in animals, plants, and fungi. We investigated a metallothionein-like (mt-like) gene shown previously to be upregulated in fruiting bodies of the fungus Agaricus bisporus in response to post-harvest storage. Analysis of an A. bisporus genomic DNA cosmid library identified two similar mt-like genes (met1 and met2) arranged as a bidirectional gene pair transcribed from the same promoter region. The promoter contained regulatory elements including 9 metal responsive elements and a CAAT box region 220 bp downstream of met1 that showed striking similarity to a feature in Coprinopsis cinerea mt-like gene promoters. Transcriptional analysis showed that both met genes are significantly and rapidly (within 3 hours) upregulated during post-harvest storage and expression is significantly greater in stipe and cap tissues compared with the gills. However, a strong directionality of the promoter was demonstrated, as transcript levels of met1 were at least two orders of magnitude greater than those of met2 in all samples tested.

• 생태와환경
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• 제40권4호
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• pp.489-494
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• 2007

Transcriptional modulation of metallothionein (MT) during acute metal exposures (cadmium, copper or zinc) was examined in fry of Hemibarbus mylodon, a threatened fish species in Korean peninsula. Viability of H. mylodon fry was most affected by copper exposure (up to 79% of mortality at 1 ppm for 48 hours) and considerably by cadmium exposure (21 to 54% of mortality). On the other hand, Zn showed the least adverse effect on the viability (0 to 13% of mortality) of this species. Based on the semi-quantitative RT-PCR analysis, the stimulation of MT mRNA in response to metal exposures followed generally in a dose-dependent fashion where cadmium was the most potent inducer for the induction of MT transcripts in fry (up to more than 5-fold) while the lowest response was observed in zinc-exposed group (2-fold at maximum). From the exposure using environmentally realistic doses of cadmium (0 to 0.05 ppm for 24 hours), MT expression at mRNA level was also sensitively modulated toward upregulation up to more than 3-fold as relative to non-exposed control. Results from the present study would be a good basis for understanding the adaptive capacity and stress physiology of this endangered fish species during metal pollution.

• Fisheries and Aquatic Sciences
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• 제13권2호
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• pp.112-117
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• 2010

Altered mRNA expression of two metallothionein isoforms (MT-IA and MT-IB) in response to acute heavy metal exposure was examined in mud loach, Misgurnus mizolepis, fry using a real-time RTPCR assay. Sublethal exposure (1 or 5 ${\mu}M$) to Cd, Cr, Fe, Mn, Ni, and Zn resulted in highly variable transcriptional responses of the two MT isoforms to the heavy metal ions, including upregulation, a steady state, and downregulation. Overall, the most potent inducer of both MT isoforms was Cd (up to 6-fold). Another exposure experiment using a series of doses of Cu revealed that the stimulation patterns of the two MT isoforms differed: MT-IA transcription was soon saturated at higher concentrations (about 2-fold at 1-4 ${\mu}M$ of Cu), whereas the activation of MT-IB was more dependent on the treatment dose (increased up to 5-fold at 3 ${\mu}M$). The isoform-specific allotment of constitutive and inducible functions was not as clear in fry as in adult tissues. Coordinated interaction between the MT-IA and MT-IB isoforms was hypothesized based on the finding that MT-IA represented a primary action under 'less stressful' or 'sublethal' conditions, whereas the activation of MT-IB became important under 'more stressful' or 'lethal' circumstances in this species.

• Toxicological Research
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• 제17권3호
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• pp.173-180
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• 2001

This study was conducted to investigate the antitoxic component in ethanol extract of Saururus chinesis (S. chinesis). The results were as follows: Generally, detoxication effects by s. chinesis extract increased in proportion to the extract concentration. non 8 $\mu\textrm{g}$/g dosage of S. chinesis extract was administered, it showed the highest antitoxic effects in metallothionein induction. After the extract treatment, body weights generally increased In proportion to the extract concentrations. from the above results, S. chinesis extract Increased Metallothionein concentration and decreased the toxicity of cadmium In rats. In vitro the antitoxic activity of ethanol extract of S. chinesis on NIH3T3 fibroblasts was evaluated by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) and SRB (sulforhodamine B protein) assays. The light microscopic study was carried out to observe morphological changes of the treeated cells. $10^{-2}$mg/ml Concentrations of S. chinesis extract was shown significant antitoxic activity. The number of NIH 3T3 fibroblasts were increased and tend to regenerate. These result suggest that S. chinesis extract retains a potential antitoxic activity.

• 한국환경보건학회지
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• 제18권1호
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• pp.95-104
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• 1992

The influence of selenium to several toxic effects of cadmum, including lethality has been shown following pretreatment with cadmium, zinc and seleniurm Five groups of rats, each consisting of 16 rats, were studied and each group was divided into four subgroups, 4 rats for each subgroup. After subcutaneous pretreatment during 5 days with saline, CdCl$_{2}$ (0.5mg/kg, ZnCl$_{2}$ (13.0mg/kg) and $Na_{2}SeO_{3}$(1.0mg/kg), rats were given intraperitioneal administration of various dosage of or cadium of cadmium and selenium. After giving the challenge dose, cadmium and metallothionein(MT) concentrations were determined in liver and kidney The concentration of cadmium in liver and kideny increased proportionally to the increase of challenge dosage. The simultaneous administration of cadmium and selenium significantly more decrease cadmium concentrations in liver and kidney than those of the administration of cadmium only. However, MT concentrations in liver and kideny were increased by the pretreatment of cacmium, zinc and selenium. Our results suggest that increasing cadmium concentrations, gradully accumulating in the tissues of liver and kidney as a result of the pretreatment, served to induced the synthesis of MT, thus making them resistant to the challenge from cadmium.