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Journal ArticleDOI

Differential regulation of the rainbow trout ( Oncorhynchus mykiss ) MT-A gene by nuclear factor interleukin-6 and activator protein-1

17 Dec 2013-BMC Molecular Biology (BioMed Central)-Vol. 14, Iss: 1, pp 28-28
TL;DR: The involvement of NF-IL6 and AP1 in rtMT-A gene expression following exposure to oxidative stress and tumour promotion suggests an involvement of MT in protection during pathological processes such as inflammation and cancer.
Abstract: Previously we have identified a distal region of the rainbow trout (Oncorhynchus mykiss) metallothionein-A (rtMT-A) enhancer region, being essential for free radical activation of the rtMT-A gene. The distal promoter region included four activator protein 1 (AP1) cis-acting elements and a single nuclear factor interleukin-6 (NF-IL6) element. In the present study we used the rainbow trout hepatoma (RTH-149) cell line to further examine the involvement of NF-IL6 and AP1 in rtMT-A gene expression following exposure to oxidative stress and tumour promotion. Using enhancer deletion studies we observed strong paraquat (PQ)-induced rtMT-A activation via NF-IL6 while the AP1 cis-elements showed a weak but significant activation. In contrast to mammals the metal responsive elements were not activated by oxidative stress. Electrophoretic mobility shift assay (EMSA) mutation analysis revealed that the two most proximal AP1 elements, AP11,2, exhibited strong binding to the AP1 consensus sequence, while the more distal AP1 elements, AP13,4 were ineffective. Phorbol-12-myristate-13-acetate (PMA), a known tumor promoter, resulted in a robust induction of rtMT-A via the AP1 elements alone. To determine the conservation of regulatory functions we transfected human Hep G2 cells with the rtMT-A enhancer constructs and were able to demonstrate that the cis-elements were functionally conserved. The importance of NF-IL6 in regulation of teleost MT is supported by the conservation of these elements in MT genes from different teleosts. In addition, PMA and PQ injection of rainbow trout resulted in increased hepatic rtMT-A mRNA levels. These studies suggest that AP1 primarily is involved in PMA regulation of the rtMT-A gene while NF-IL6 is involved in free radical regulation. Taken together this study demonstrates the functionality of the NF-IL6 and AP-1 elements and suggests an involvement of MT in protection during pathological processes such as inflammation and cancer.

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Citations
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Journal ArticleDOI
TL;DR: The primary fish gill cell culture system (FIGCS) is an in vitro technique which has the potential to replace animals in whole effluent toxicity tests and the increase in the expression of genes encoding mta, cyp1a1 and cyp3a27 in FIGCS is indicative of the presence of biologically active pollutants.

19 citations


Cites background from "Differential regulation of the rain..."

  • ...The distal region of the rainbow 319 trout mta promoter possess both activator protein 1 (AP1) and a nuclear factor interleukin-6 320 (NF-IL6) elements that have been shown to play a direct role in mta induction in response to 321 paraquat, an herbicide that induces ROS (Kling et al., 2013)....

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  • ...Some pharmaceuticals and personal care products 316 have been shown to affect reactive oxygen species(ROS) production in rainbow trout gonad 317 cell line (RTG-2) (Fernandez et al., 2013) and PAHs are known to induce free radical 318 production (e.g. Wells and Winn 1996; Zhu et al., 2014)....

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  • ...Effects of human 402 pharmaceuticals on cytotoxicity, EROD activity and ROS production in fish hepatocytes....

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  • ...In addition, FIGCS treated with 322 H2O2, that produces ROS, show an increase in mta and b gene expression, as well as other 323 antioxidant genes (Chung et al., 2005)....

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  • ...The antioxidant gene expression is attenuated by the 324 14 zinc chelator N,N,N’,N’-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN), suggesting that the 325 response to ROS in FIGCS is in part mediated by an increase in intracellular zinc 326 concentrations (Chung et al., 2005)....

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Journal ArticleDOI
TL;DR: The results of this study raise a possibility that a genetic variation of MT2A may be implicated in the etiology of laryngeal cancer in a Polish population.
Abstract: Metallothioneins are intracellular regulators of many biological mechanisms including differentiation, proliferation, angiogenesis and invasion, which are crucial processes in carcinogenesis. This study examines the association between three single-nucleotide polymorphisms at loci -5 A/G (rs28366003) and -209 A/G (rs1610216) in the core promoter region and at locus +838 C/G (rs10636) in 3'UTR region of the metallothionein 2A (MT2A) gene with squamous cell laryngeal cancer (SCLC) risk, as well as with tumor invasiveness according to tumor front grading (TFG). Genotyping was performed using the polymerase chain reaction-restriction fragment length polymorphism technique in 323 genetically unrelated individuals with SCLC and 418 randomly selected healthy volunteers. Only one SNP (rs28366003) was significantly related to laryngeal cancer in the study population. Compared with homozygous common allele carriers, heterozygous and homozygous for the G variant had significantly increased risk of SCLC [adjusted odds ratio (OR) = 2.90, 95 % confidence interval (CI) 1.53-5.21, p dominant 18 points) (OR = 3.76, 95 % CI 1.15-12.56, p = 0.03) and diffuse tumor growth (OR = 5.86, 95 % Cl 0.72-44.79, p = 0.08). The results of this study raise a possibility that a genetic variation of MT2A may be implicated in the etiology of laryngeal cancer in a Polish population.

14 citations


Cites background from "Differential regulation of the rain..."

  • ...MT promoter activity is regulated by six zinc-finger metalresponsive transcription factor (MTF-1) and a nuclear factor I (NF-I) protein [2]....

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Journal ArticleDOI
TL;DR: The findings suggest that MT2A gene variation rs28366003 may be implicated in the etiology of sinonasal inverted papilloma in a Polish population.
Abstract: Inverted papillomas are a unique group of locally aggressive benign epithelial neoplasms in the nasal cavity and paranasal sinuses arising from the Schneiderian mucosa. Metallothioneins are sulfhydryl-rich heavy metal-binding proteins required for metal toxicity protection and regulation of biological mechanisms including proliferation and invasion. The goal of this study was to identify three SNPs at loci −5 A/G (rs28366003) and −209 A/G (rs1610216) in the core promoter region and at locus +838 C/G (rs10636) in 3′UTR region of the MT2A gene with IP risk and with tumor invasiveness according to Krouse staging. Genotyping was performed using the PCR restriction fragment length polymorphism technique in 130 genetically unrelated IP individuals, and 418 randomly selected healthy volunteers. The presence of the rs28366003 SNP was significantly related to the risk of IP within the present population-based case-control study. Compared to homozygous common allele carriers, heterozygosity and homozygosity for the G variant had a significantly increased risk of IP (adjusted odds ratio [OR] = 7.71, 95 % confidence interval [CI]: 4.01–14.91, p dominant < 0.001). Moreover, risk allele carriers demonstrated higher Krouse stage (pT1 vs. pT2-4) (OR = 19.32; 95 % CI, 2.30–173.53; p < 0.0001), diffuse tumor growth (OR = 4.58; 95 % CI, 1.70–12.11; p = 0.0008), bone destruction (OR = 4.13; 95 % CI, 1.50–11.60; p = 0.003), and higher incidence of tumor recurrences (OR = 5.11; 95 % CI, 1.68–15.20; p = 0.001). The findings suggest that MT2A gene variation rs28366003 may be implicated in the etiology of sinonasal inverted papilloma in a Polish population.

13 citations


Cites background from "Differential regulation of the rain..."

  • ...er region is played by the six zinc-finger-metal-responsive transcription factor (MTF-1) and short cis-acting DNA metal response elements (MREs) as transcriptional activators and a nuclear factor I (NF-I) protein as a downregulator of MT expression [11]....

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Journal ArticleDOI
TL;DR: Interestingly, Pl-Fra expression was induced by the different metals and the induction kinetics revealed its persistent expression during treatments, and its temporal and spatial behavior in response to the three metals was comparable to that of Pl-jun and Pl-MT.

12 citations

Journal ArticleDOI
TL;DR: Results indicate that neither INVX nor S25-7 is upregulated upon immune system activation; thus, teleosts have evolved a system of immune regulation that is different than that found in mammals.
Abstract: Major histocompatibility complex (MHC) class II-associated invariant chain is a chaperone responsible for targeting the MHC class II dimer to the endocytic pathway, thus enabling the loading of exogenous antigens onto the MHC class II receptor. In the current study, in vivo and in vitro methods were used to investigate the regulation of the rainbow trout invariant chain proteins S25-7 and INVX, upon immune system activation. Whole rainbow trout and the macrophage/monocyte-like cell line RTS11 were treated with PMA at concentrations shown to induce IL-1β transcripts and homotypic aggregation of RTS11. S25-7 transcript levels remained unchanged in the gill, spleen, and liver and were found to be significantly decreased in head kidney beginning 24 h post-stimulation. Meanwhile, INVX transcript levels remained unchanged in all tissues studied. Both S25-7 and INVX proteins were produced in gill and spleen tissues but their expression was unaffected by immune system stimulation. Surprisingly, neither INVX nor S25-7 protein was detected in the secondary immune organ, the head kidney. Analysis of RTS11 cultures demonstrated that both INVX and S25-7 transcript levels significantly increased at 96 h and 120 h following PMA stimulation before returning to control levels at 168 h. Meanwhile, at the protein level in RTS11, S25-7 remained unchanged while INVX had a significant decrease at 168 h post-stimulation. These results indicate that neither INVX nor S25-7 is upregulated upon immune system activation; thus, teleosts have evolved a system of immune regulation that is different than that found in mammals.

11 citations

References
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Journal ArticleDOI
TL;DR: It is reported here that activation of the NQO1 ARE by tert-butylhydroquinone (tBHQ) is dependent on Nrf2 and not oxidative stress in IMR-32 human neuroblastoma cells, and results suggest that ARE activation signals from tBHQ and DEM converge at NRF2 transcription factor through independent mechanisms.

127 citations


"Differential regulation of the rain..." refers background in this paper

  • ...However, it has been indicated that ARE driven gene expression can occur in the absence of oxidative stress through the transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf-2) [26]....

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Journal ArticleDOI
TL;DR: It is shown that the high basal level of transcription of the human metallothionein-IIA gene is due to the presence of an enhancer element within the hMT- IIA promoter region, which suggests a possible functional and evolutionary relationship between enhancers and upstream promoter elements.
Abstract: Initiation of transcription by RNA polymerase II in eukaryotes is strongly increased by cis-acting genetic elements, known as activators or enhancers. Enhancers, first detected in simian virus 40 (SV40), were subsequently also found to control the expression of several cellular genes. The human metallothionein-IIA (hMT-IIA) gene, although inducible by heavy metals and glucocorticoids, is widely expressed in most cell types in the absence of inducers. Here we show that the high basal level of transcription of the hMT-IIA gene is due to the presence of an enhancer element within the hMT-IIA promoter region. The structural and functional organization of this cellular enhancer element in two direct repeats is strikingly similar to that of the enhancer element of SV40. This suggests a possible functional and evolutionary relationship between enhancers and upstream promoter elements.

109 citations


"Differential regulation of the rain..." refers background in this paper

  • ...The composite transcription factor AP1 was first identified as a factor mediating optimal basal level expression of the human MT2A (hMT2A) enhancer region [15-17]....

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Book ChapterDOI
TL;DR: It is demonstrated that MT deficiency renders animals more vulnerable to acetaminophen-induced hepatotoxicity, and the increased sensitivity does not appear to be due to increased acetaminphen activation, glutathione depletion, or covalent binding, but appears to be associated with the antioxidant role of MT.
Abstract: Metallothioneins (MTs) are a group of low-molecular weight, cysteine-rich, metal-binding proteins. MT has an unusually high sulfhydryl content, and thus it has been suggested to react with free radicals and electrophiles [1–2].

99 citations


"Differential regulation of the rain..." refers background in this paper

  • ...The role of metallothionein (MT) as a free radical scavenger has been well documented in vitro [3], in cell lines [4], and at the organism level [5,6]....

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Journal ArticleDOI
TL;DR: Evidence suggests that cellular oxidation can induce changes in gene expression during normal development, and one basis of oxidative influence on gene expression stems from changes in cellular calcium distribution.
Abstract: Metabolic gradients are known to influence cellular differentiation at critical junctures of development. The existence of these gradients will stimulate variations in the rate of generation of active oxygen metabolites by metabolic pathways. Recent evidence suggests that cellular oxidation can induce changes in gene expression during normal development. Conversely, antioxidants such as ascorbate, alpha-tocopherol and beta-carotene are inhibitory to differentiation in many types of cells. One basis of oxidative influence on gene expression stems from changes in cellular calcium distribution.

96 citations


"Differential regulation of the rain..." refers background in this paper

  • ...suggested that antioxidants such as ascorbate, αtocopherol and β-carotene are inhibitory to differentiation [40]....

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Journal ArticleDOI
04 Apr 1986-Science
TL;DR: The data presented are consistent with a model in which heavy metal ions control the ability of the hMT-IIA enhancer to bind a positive factor, leading to increased transcription, which suggests that viruses utilize factors that have a normal role in cellular gene expression to control their own genes.
Abstract: The human metallothionein-IIA (hMT-IIA) gene contains an enhancer element within its 5' regulatory region. This enhancer element can compete with the SV40 enhancer for one or more cellular factors in vivo. The competition between the two elements is modulated by cadmium, an inducer of hMT-IIA transcription. The data presented are consistent with a model in which heavy metal ions control the ability of the hMT-IIA enhancer to bind a positive factor, leading to increased transcription. The same factor is required for maximal activity of the SV40 enhancer, which suggests that viruses utilize factors that have a normal role in cellular gene expression to control their own genes.

85 citations


"Differential regulation of the rain..." refers background in this paper

  • ...The composite transcription factor AP1 was first identified as a factor mediating optimal basal level expression of the human MT2A (hMT2A) enhancer region [15-17]....

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