Endogenous and heavy-metal-ion-induced metallothionein gene expression in salmonid tissues and cell lines

Zafarullah, Muhammad; Olsson, Per‐Erik; Gedamu, Lashitew

doi:10.1016/0378-1119(89)90406-x

Cited by 64 publications

(16 citation statements)

References 26 publications

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“…Metallothionein levels in fish may be induced by heavy metals, stress, glucocorticoids, oxidative stress, and inflammation [15,16,36]. The current findings that zinc sulfate increased MT levels in striped bass agrees with previous investigations in several piscine species [23,24]. Metallothionein levels differed in fish across the SFE, a finding similar to that found in other estuaries [8].…”

Section: Metallothioneinsupporting

confidence: 93%

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Environmental contaminant effects on juvenile striped bass in the San Francisco Estuary, California, USA

Spearow

Kota

Ostrach

2010

Enviro Toxic and Chemistry

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The decline of pelagic organisms in the San Francisco Estuary (SFE) (California, USA) is attributed to several factors, including water diversions, invasive species, and exposure to environmental toxicants. The present study evaluated the effects of environmental contaminants on liver vitellogenin, metallothionein, 7-ethoxyresorufin-O-deethylase (EROD), and benzyloxyresorufin O-deethylase (BROD) activity in juvenile striped bass (Morone saxitilis) in the SFE. Analysis of juvenile striped bass liver extracts revealed site-specific elevations of vitellogenin, metallothionein, and EROD biomarkers across the estuary. Although some striped bass in the estuary showed EROD activity similar to unhandled hatchery controls, several sites in the estuary showed significantly higher EROD activity that was in the range of beta-naphthoflavone (BNF)-injected, positive controls. Overall, EROD activity averaged 283% higher in estuary fish than in hatchery controls. Chemical analyses of extracts from semipermeable membrane devices (SPMDs) deployed in the estuary for one month showed elevated polyaromatic hydrocarbon (PAH) levels. Semipermeable membrane devices extract injections-induced metallothionein and BROD in striped bass livers. These data show that environmental exposures are impacting EROD and other biomarkers in the SFE striped bass population. Previous studies in our laboratory have associated poor larval development with maternal transfer of environmental contaminants. Further studies are needed to monitor contaminant exposures by the use of biomarkers and to integrate them into a more effective pelagic species recovery plan in the SFE.

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Section: Metallothioneinsupporting

confidence: 93%

“…5). This confirms the effect of zinc on MT levels in piscine species [23,24] and provides additional evidence for the validation of the MT ELISA assay. Figure 5 shows the levels of MT per mg liver protein in striped bass estuary samples.…”

Section: Metallothioneinsupporting

confidence: 79%

Environmental contaminant effects on juvenile striped bass in the San Francisco Estuary, California, USA

Spearow

Kota

Ostrach

2010

Enviro Toxic and Chemistry

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“…These early proposals were considered controversial due to a lack of general understanding of MT function in aquatic animals. While it is has been known for some time that metals such as Cd, Zn, and Cu can induce MTs in aquatic animals, detailed studies at the cellular and molecular level have only recently been reported (21 (22,25,(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43) …”

mentioning

confidence: 99%

Metallothionein induction as a measure of response to metal exposure in aquatic animals.

Roesijadi

1994

Environ Health Perspect

145

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Metallothioneins (MTs) are considered central in the intracellular regulation of metals such as copper, zinc, and cadmium. Increased MT synthesis is associated with increased capacity for binding these metals and protection against metal toxicity. Recent advances in the biochemistry and molecular biology of MTs have facilitated research on MTs in aquatic species. For the bivalve mollusc Crassostrea virginica, a species frequently used in studies on the toxicology and environmental monitoring of metals, the primary structure for MT has been deduced from analysis of the proteins and cDNA. Procedures for analysis of MT synthesis and MT gene expression have been applied in studies of response to metal exposure. Induction of specific MT forms by Cd is concentration-and time-dependent. The levels of MT-bound metals exhibit a strong relationship with the cytosolic metal concentrations in a metal-exposed natural population of oysters. Ribonuclease protection assays using sequence-specific antisense RNA probes have shown that the MT mRNA structure in this natural population exhibits considerable individual variability in the 3'-untranslated region. Although yet to be substantiated, the possibility exists that the distribution of this variability may be related to the level of environmental metal contamination. (3,20,21) attests to the conserved nature of MT and its function. Amino acid sequences of varied species including aquatic animals show regions of high similarity (22). Conserved nucleotide sequences exist for both coding region and regulatory elements of MTs of mammals, fish, and invertebrates (23-25).The initial reports describing the occurrence of MTs in aquatic animals (26,27) were soon followed by proposals for use of MTs in assessing the environmental toxicity of metals (28,29). These early proposals were considered controversial due to a lack of general understanding of MT function in aquatic animals. While it is has been known for some time that metals such as Cd, Zn, and Cu can induce MTs in aquatic animals, detailed studies at the cellular and molecular level have only recently been reported (21 (22,25,(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)

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“…22) In many fish species, including the crucian carp, only one isoform appears to be present 23,24) and synthesis is transcriptionally regulated by metals such cadmium. 25,26) Recently, the Japanese crucian carp (Carassius cuvieri, C. cuvieri) has been reported to synthesize two major isoforms of MT (ccMT-1 and ccMT-2) in the liver and kidney by several inducers including air-pumping stress, dexamethasone, and metals. 18,19) The cDNA sequence and deduced amino acid sequence were compared with those of the published sequences using the NCBI BLAST search program.…”

Section: Sequence Of Mt Gdna and Cdnamentioning

confidence: 99%

Metallothionein mRNA Sequencing and Induction by Cadmium in Gills of the Crucian Carp, Carassius auratus

Bae

Nam

Park

et al. 2005

JOURNAL OF HEALTH SCIENCE

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Metallothioneins (MTs) are inducible metal-binding proteins characterized by low molecular weight (6000-10000 Da) and play a major role in detoxification of heavy metals. They are known to be induced by heavy metals in various organs of different species and represent a potential biomarker of aquatic contamination with heavy metals. In this study, cloning and sequencing of a MT gene of the Korean freshwater fish, the crucian carp (Carassius auratus), were performed. Furthermore, the gene expression and cadmium accumulation in the gills of the crucian carp were compared during the cadmium exposure period of 25 days. The MT gene, lacking the 5′ promoter region, is 405 bp long and has a tripartite structure consisting of three exons and two introns. The open reading frame encodes a cysteine-rich (20 cysteines) polypeptide of 60 amino acids containing six Cys-X-Cys motifs, typically found in this protein family. It was found that the expression of MT mRNA of gills was very low in normal control fish but high mRNA expression was induced after 1-day exposure to cadmium. However, the mRNA levels decreased after 1 day even though the cumulative cadmium concentration increased during the remaining exposure period. These results suggest that MT expression does not always reflect the cadmium accumulation in the gills of the fish and may have limitations in its use as a biomarker to monitor cadmium contamination of aquatic environments.

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Endogenous and heavy-metal-ion-induced metallothionein gene expression in salmonid tissues and cell lines

Cited by 64 publications

References 26 publications

Environmental contaminant effects on juvenile striped bass in the San Francisco Estuary, California, USA

Environmental contaminant effects on juvenile striped bass in the San Francisco Estuary, California, USA

Metallothionein induction as a measure of response to metal exposure in aquatic animals.

Metallothionein mRNA Sequencing and Induction by Cadmium in Gills of the Crucian Carp, Carassius auratus

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