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Forcella M, Lau P, Oldani M, Melchioretto P, Bogni A, Gribaldo L, Fusi P, Urani C. Neuronal specific and non-specific responses to cadmium possibly involved in neurodegeneration: A toxicogenomics study in a human neuronal cell model. Neurotoxicology 2020; 76:162-173. [DOI: 10.1016/j.neuro.2019.11.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 10/23/2019] [Accepted: 11/06/2019] [Indexed: 12/14/2022]
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Forcella M, Callegaro G, Melchioretto P, Gribaldo L, Frattini M, Stefanini FM, Fusi P, Urani C. Cadmium-transformed cells in the in vitro cell transformation assay reveal different proliferative behaviours and activated pathways. Toxicol In Vitro 2016; 36:71-80. [PMID: 27432484 DOI: 10.1016/j.tiv.2016.07.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Revised: 06/28/2016] [Accepted: 07/13/2016] [Indexed: 12/11/2022]
Abstract
The in vitro Cell Transformation Assay (CTA) is a powerful tool for mechanistic studies of carcinogenesis. The endpoint is the classification of transformed colonies (foci) by means of standard morphological features. To increase throughput and reliability of CTAs, one of the suggested follow-up activities is to exploit the comprehension of the mechanisms underlying cell transformation. To this end, we have performed CTAs testing CdCl2, a widespread environmental contaminant classified as a human carcinogen with the underlying mechanisms of action not completely understood. We have isolated and re-seeded the cells at the end (6weeks) of in vitro CTAs to further identify the biochemical pathways underlying the transformed phenotype of foci. Morphological evaluations and proliferative assays confirmed the loss of contact-inhibition and the higher proliferative rate of transformed clones. The biochemical analysis of EGFR pathway revealed that, despite the same initial carcinogenic stimulus (1μM CdCl2 for 24h), transformed clones are characterized by the activation of two different molecular pathways: proliferation (Erk activation) or survival (Akt activation). Our preliminary results on molecular characterization of cell clones from different foci could be exploited for CTAs improvement, supporting the comprehension of the in vivo process and complementing the morphological evaluation of foci.
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Affiliation(s)
- M Forcella
- Department of Biotechnology and Biosciences, University of Milan Bicocca, Piazza della Scienza 3, 20126 Milan, Italy
| | - G Callegaro
- Department of Earth and Environmental Sciences, University of Milan Bicocca, Piazza della Scienza 1, 20126 Milan, Italy
| | - P Melchioretto
- Department of Earth and Environmental Sciences, University of Milan Bicocca, Piazza della Scienza 1, 20126 Milan, Italy
| | - L Gribaldo
- Institute for Health and Consumer Protection, DG JRC, European Commission, Via Enrico Fermi 2749, 21027 Ispra, Varese, Italy
| | - M Frattini
- Istituto Cantonale di Patologia, Via in Selva 24, 6601 Locarno, Switzerland
| | - F M Stefanini
- Department of Statistics, Computer Science, Applications, University of Florence, Viale Morgagni 59, 50100 Florence, Italy
| | - P Fusi
- Department of Biotechnology and Biosciences, University of Milan Bicocca, Piazza della Scienza 3, 20126 Milan, Italy.
| | - C Urani
- Department of Earth and Environmental Sciences, University of Milan Bicocca, Piazza della Scienza 1, 20126 Milan, Italy.
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Urani C, Melchioretto P, Gribaldo L. Regulation of metallothioneins and ZnT-1 transporter expression in human hepatoma cells HepG2 exposed to zinc and cadmium. Toxicol In Vitro 2009; 24:370-4. [PMID: 19900532 DOI: 10.1016/j.tiv.2009.11.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2009] [Revised: 10/29/2009] [Accepted: 11/04/2009] [Indexed: 10/20/2022]
Abstract
Essential and non-essential metals can affect vital cellular processes, when over-accumulated within the cells. For this reason, cells have evolved multiple protein sensors, transporters, and other type of proteins to regulate and control free metal homeostasis. Among these, metallothioneins (MT) and ZnT-1 transporter play a key role in the regulation of free Zn concentrations. Herewith, MT expression in Zn (170microM) and Cd (0.1 and 10microM) exposed HepG2 cells is analyzed and compared. In addition, the modulation and localization of the membrane transporter ZnT-1 has been investigated. MT-I and MT-II were up-regulated in response to both Zn and Cd exposure and, as expected, Cd represented the most potent inducer. Namely, 0.1microM Cd was able to up-regulate MT-I, and -II in a way comparable to 170microM Zn. This is in agreement with MT general function of metal-chelating protein, acting with higher tolerance to essential metals than to non-essential ones. ZnT-1 protein, a plasma membrane specific Zn transporter, was up-regulated as well by both Zn and Cd, although in the same way. Immunofluorescence technique provided evidence that high levels of ZnT-1 measured by biochemical techniques, are related to an increased localization of the transporter at the plasma membrane.
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Affiliation(s)
- C Urani
- Environmental Science Department, University of Milano Bicocca, Piazza della Scienza 1, 20126 Milano, Italy.
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Urani C, Melchioretto P, Canevali C, Morazzoni F, Gribaldo L. Metallothionein and hsp70 expression in HepG2 cells after prolonged cadmium exposure. Toxicol In Vitro 2007; 21:314-9. [PMID: 17055695 DOI: 10.1016/j.tiv.2006.08.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2006] [Revised: 08/23/2006] [Accepted: 08/31/2006] [Indexed: 11/28/2022]
Abstract
Cadmium is a widely distributed industrial and environmental pollutant. Principle target organs are soft tissues such as the liver, where cadmium accumulates with a biological half-life of approximately 20-30 years causing a variety of toxic responses. In HepG2, CdCl(2) exposure for short periods (from 1 to 24h) induces differential expression of stress proteins, including MT and hsp70. However, less is known about the stress response during a prolonged exposure to this metal. MTT assay showed a low cytotoxicity of CdCl(2) (0.1, 0.5, 1, 2, 5, 10microM), over a period of 72h. Cadmium uptake by ICP-AES technique and the corresponding expression of stress proteins (MT, hsp70) during the same prolonged time were also analysed. Results show that Cd was continuously and increasingly accumulated, at the highest of the concentrations tested. Metallothionein expression was up-regulated with a saturation curve at 48 as well as 72h after CdCl(2) exposure. High levels of MT probably confer an acquired tolerance to the stress and protection against cell injury as demonstrated by low cytotoxicity values. On the contrary, the unchanged pattern of hsp70 expression suggests that this protective mechanism, unlike other members of the family, is less involved during CdCl(2) prolonged exposure.
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Affiliation(s)
- C Urani
- Dipartimento di Scienze dell'Ambiente e del Territorio, Università degli Studi di Milano Bicocca, Italy.
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Urani C, Melchioretto P, Canevali C, Crosta GF. Cytotoxicity and induction of protective mechanisms in HepG2 cells exposed to cadmium. Toxicol In Vitro 2005; 19:887-92. [PMID: 16081243 DOI: 10.1016/j.tiv.2005.06.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2005] [Accepted: 06/17/2005] [Indexed: 11/28/2022]
Abstract
Cadmium is a widespread industrial pollutant. The primary route of exposure occurs via contaminated drinking water or food supplies, and tobacco. Its chronic introduction and ingestion lead to bio-magnification in target organs, as the liver. The aim of this paper is to determine Cd cytotoxic concentrations in the human hepatoma cell line HepG2. Further aims are the study of the activation and involvement of protection mechanisms against Cd hepatotoxicity. Cd was accumulated within the cells, as measured by ICP-AES. Metallothioneins (MT-1 and -2), a family of metal-binding proteins, were induced in a dose-dependent way after treatment with concentrations below the IC(50) value (mean value 22 microM). The over-expression of MT by Zn pre-treatment was able to defend against Cd cytotoxicity. Heat shock protein 70 kDa (hsp70) was induced at high non-cytotoxic concentrations (5, 10 microM) probably as a consequence of proteotoxicity, but its over-expression by a sub-lethal heat shock was not able to protect the cells from Cd cytotoxic concentrations (20, 50, 100 microM).
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Affiliation(s)
- C Urani
- Dipartimento di Scienze dell'Ambiente e del Territorio, Università degli Studi di Milano Bicocca, piazza della Scienza, 1 20126 Milano, Italy.
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Urani C, Calini V, Melchioretto P, Morazzoni F, Canevali C, Camatini M. Different induction of metallothioneins and Hsp70 and presence of the membrane transporter ZnT-1 in HepG2 cells exposed to copper and zinc. Toxicol In Vitro 2003; 17:553-9. [PMID: 14599444 DOI: 10.1016/s0887-2333(03)00117-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Eukaryotic cells respond to stressful environmental stimuli, such as toxic concentrations of heavy metals, by rapidly synthesising defence proteins: the metallothioneins (MT) and the heat shock protein 70 (Hsp70). In this study we have analysed how the human hepatoblastoma cell line HepG2 responds to exposure to excess copper (30 microg/ml) and zinc (50 microg/ml) for long exposure times (48 and 72 h). Accumulation of the two metals, as measured by ICP-AES, was time-dependent reaching a plateau after 72 h. HepG2 cells responded by dramatically increasing levels of MT during stress, mostly during zinc exposure. A time lag in Hsp70 induction was observed as the levels of this protein increased only after removal of the stress from culture medium (recovery) for 24 h, thus suggesting that the two defence mechanisms are not coordinated in a metal-induced stress response. Moreover in HepG2 cells, immunochemical and fluorescence techniques showed the presence and the localisation of the zinc membrane exporter ZnT-1 as a further mechanism of defence/homeostasis against zinc toxicity.
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Affiliation(s)
- C Urani
- Dipartimento di Scienze dell'Ambiente e del Territorio, Università degli Studi di Milano Bicocca, p.zza della Scienza 1, 20126 Milan, Italy.
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Abstract
The aim of this work is to study the accumulation in HepG2 cells of two essential metals with toxic potency and to analyse the induction of the heat shock protein 70 kDa (hsp70) consequent to metal exposure. Cu and Zn were the metals considered and were analysed both as single compounds and in combination in order to evidence synergic effects of the mixture. The use of HepG2 cells provided an in vitro system that retains morphological and metabolic properties and the expression of specific genes typical of liver parenchymal cells. Moreover, the hepatic cells represent a suitable model for their susceptibility to metal toxicity since liver, gastrointestinal tract and renal tubular cells are involved in the uptake, transport, detoxification and secretion of these compounds. The uptake of Cu and Zn followed a time-dependent accumulation when they were used separate. The combination of the two metals produced a higher accumulation of Zn. The stress protein hsp70 was expressed before the metals accumulated within the cells, as shown by the measures obtained with the ICP-AES technique. Moreover, the accumulation of hsp70 by a sublethal shock provided a protective mechanism against metal cytotoxicity.
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Affiliation(s)
- C Urani
- Dipartimento di Scienze dell'Ambiente e del Territorio, Università degli Studi di Milano Bicocca, p.zza della Scienza 1, 20126 Milan, Italy
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Agostoni Carbone ML, Lucchini G, Melchioretto P, Nardese V, Vanoni M, Panzeri L. A 9359 bp fragment from the right arm of Saccharomyces cerevisiae chromosome VII includes the FOL2 and YTA7 genes and three unknown open reading frames. Yeast 1998; 14:587-91. [PMID: 9605509 DOI: 10.1002/(sici)1097-0061(19980430)14:6<587::aid-yea268>3.0.co;2-i] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
In the framework of the EU programme for systematic sequencing of the Saccharomyces cervisiae genome we determined the sequence of a 9359 bp fragment of the right arm of chromosome VII. Five open reading frames (ORFs) of at least 300 nucleotides were found in this region. YGR267c encodes a protein with significant similarity to the enzyme GTP-cyclohydrolase I, that controls the first step in the biosynthetic pathway leading to various pterins and shows a high degree of sequence conservation from bacteria to mammals. We have recently demonstrated (Nardese et al., 1996) that YGR267c corresponds to the FOL2 gene, previously localized in the same chromosomal region by genetic mapping. The protein deduced from YGR270w belongs to the superfamily of putative ATPases associated with diverse cellular activities. It corresponds to the YTA7 gene, a member of a set of yeast genes coding for putative ATPases with high similarity to constituents of the 26S protease. The three ORFs YGR266w, YGR268c and YGR269w encode putative products of unknown function, with neither significant similarity to proteins in databases nor recognizable domains. YGR268c and YGR269w are partially overlapping ORFs: YGR268c seems to correspond to a real gene. whereas YGR269w is probably a fortuitous ORF.
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Affiliation(s)
- M L Agostoni Carbone
- Dipartimento di Genetica e di Biologia dei Microrganismi, Università di Milano, Italy
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Feroli F, Carignani G, Pavanello A, Guerreiro P, Azevedo D, Rodrigues-Pousada C, Melchioretto P, Panzeri L, Agostoni Carbone ML. Analysis of a 17.9 kb region from Saccharomyces cerevisiae chromosome VII reveals the presence of eight open reading frames, including BRF1 (TFIIIB70) and GCN5 genes. Yeast 1997; 13:373-7. [PMID: 9133742 DOI: 10.1002/(sici)1097-0061(19970330)13:4<373::aid-yea82>3.0.co;2-v] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We report the nucleotide sequence of a 17,893 bp DNA segment from the right arm of Saccharomyces cerevisiae chromosome VII. This fragment begins at 482 kb from the centromere. The sequence includes the BRF1 gene, encoding TFIIIB70, the 5' portion of the GCN5 gene, an open reading frame (ORF) previously identified as ORF MGA1, whose translation product shows similarity to heat-shock transcription factors and five new ORFs. Among these, YGR250 encodes a polypeptide that harbours a domain present in several polyA binding proteins. YGR245 is similar to a putative Schizosaccharomyces pombe gene, YGR248 shows significant similarity with three ORFs of S. cerevisiae situated on different chromosomes, while the remaining two ORFs, YGR247 and YGR251, do not show significant similarity to sequences present in databases.
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Affiliation(s)
- F Feroli
- Dipartimento di Chimica Biologica, Università di Padova, Italy
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Sora S, Melchioretto P, Primignani P, Agostoni Carbone ML. Caffeine interactions with methyl methanesulphonate, hycanthone, benlate, and cadmium chloride in chromosomal meiotic segregation of Saccharomyces cerevisiae. Mutat Res 1988; 201:9-16. [PMID: 2458529 DOI: 10.1016/0027-5107(88)90106-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Interactions of caffeine with chemicals known for their effects on chromosomal segregation during meiosis of Saccharomyces cerevisiae were studied. It appears that caffeine does interfere with the action of other compounds during the different phases of meiosis. Treatments with methyl methanesulphonate (MMS) and cadmium chloride (CdCl2) resulted in a synergistic effect consisting of an increase in the frequency of recombination. The greatest effects were found on the induction of diploid spores: MMS, hycanthone, and distamycin demonstrated strong, benlate little synergistic action. CdCl2 demonstrated antagonism to caffeine by counter-inhibiting its effect on the induction of diploids. Concerning disomic induction: caffeine reduced (or left unchanged) the effect on non-disjunction when MMS and hycanthone were used. Simple additive effects were caused in conjunction with distamycin, benlate, and (in small doses) CdCl2. 2 mg of caffeine/ml in treatments with CdCl2 resulted in a very high frequency of disomic clones.
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Affiliation(s)
- S Sora
- Dipartimento di Genetica e di Biologia dei Microrganismi, Università di Milano, Italy
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