Search results for "Metallothionein"
showing 10 items of 60 documents
Metallothionein in the freshwater gastropod Melanopsis dufouri chronically exposed to cadmium: A methodological approach
2010
Previous studies have demonstrated that the use of differential pulse polarography (DPP) for metallothionein (MT) determination in marine gastropod tissues, particularly the digestive gland, requires taking into account the presence of heat-stable high molecular weight compounds that exhibit polarographic signal. In the present paper, similar compounds were identified in tissues from the freshwater snail Melanopsis dufouri which also interfere with MT determination by DPP and, due to their silver binding capacity, also interfere in the silver assay for MT quantification. Ultrafiltration seems to be effective in removing these high molecular weight compounds from heat-denatured homogenate su…
Metal concentrations and detoxification mechanisms in Solea solea and Solea senegalensis from NW Mediterranean fishing grounds
2013
10 pages, 5 figures, 4 tables
Combined effect of cadmium and sulfonamides on sea urchin development
2013
Echinoderms play a key role in the maintenance of the integrity of the ecosystem where they live. They are constantly exposed to pollutants, particularly in their early planktonic life stages. Sulfamethoxazole with trimethoprim (TMP/SMX) is a fixed antibiotic combination whose concentration is significantly increasing in the coastal waters due to human medicine and also intensive husbandry and aquaculture activities. Previously, we studied the defense strategies activated by P. lividus embryos in response to sublethal doses of CdCl2. Although toxic effects of cadmium on embryo development are not morphologically detectable before 24 hours of exposure, we found upregulation in mRNAs related …
Effects of cadmium exposition on sea urchin development by SSH and RT-qPCR techniques
2012
Cadmium (Cd) is a toxic heavy metal contaminating coastal environments. It has been suggested that the mechanisms of acute Cd toxicity involve the depletion of glutathione and protein-bound sulfhydryl groups, resulting in enhanced production of ROS. Cd-increased ROS in turn produces lipid peroxidation, and results in DNA damage. However, little is known about direct evidence and mechanism for Cd-generated radicals until recently. In order to study the early defense strategies activated by P. lividus 30 hours embryos, in response to exposition to sub-lethal doses of Cd (100μM), we analyzed the induced transcriptome comparing it to that of control embryos by Suppression Subtractive Hybridizat…
Characterization and transcription studies of a phytochelatin synthase gene from the solitary tunicate Ciona intestinalis exposed to cadmium.
2014
The major thiol-containing molecules involved in controlling the level of intracellular ROS in eukaryotes, acting as a nonenzymatic detoxification system, are metallothioneins (MTs), glutathione (GSH) and phytochelatins (PCs). Both MTs and GSH are well-known in the animal kingdom. PC was considered a prerogative of the plant kingdom but, in 2001, a phytochelatin synthase (PCS) gene was described in the nematode Caenorhabditis elegans; additional genes encoding this enzyme were later described in the earthworm Eisenia fetida and in the parasitic nematode Schistosoma mansoni but scanty data are available, up to now, for Deuterostomes. Here, we describe the molecular characteristics and transc…
Differential metallothionein expression in oral lichen planus and amalgam-associated oral lichenoid lesions
2017
Background Oral lichen planus (OLP) is a chronic inflammatory disease mediated by T cells, which manifests as reticular (white) or erosive (red) lesions, that are eventually painful. Oral lichenoid lesion (OLL) are distinguished from OLP by the presence of precipitating factors. The aim of this study was to evaluate whether the presence of metallothionein, which is involved in anti-apoptotic pathways and the anti-oxidative response, could serve as a differential diagnostic for OLP and OLL. Material and Methods We evaluated the expression of metallothionein in 40 cases of OLP and 20 cases of OLL using immunohistochemistry. Results and Conclusions White OLP has higher concentrations of metall…
Sequence-Specific Repression of Cotranslational Translocation of the Hepatitis B Virus Envelope Proteins Coincides with Binding of Heat Shock Protein…
1997
AbstractThe large L envelope protein of the hepatitis B virus has the peculiar capacity to adopt two transmembrane topologies. The N-terminal preS domain of L initially remains in the cytosol while the S domain is cotranslationally inserted into the endoplasmic reticulum membrane. The preS region of about half of the L molecules is posttranslationally translocated to the lumenal space. We now demonstrate that the repression of cotranslational translocation of preS is conferred by a preS1-specific sequence. By analysis of L deletion mutants, the cytosolic anchorage determinant was mapped to amino acid sequence 70 to 94 of L. The intrinsic potential of this determinant to suppress cotranslati…
Toxic mineral elements in Mytilus galloprovincialis from Sicilian coasts (Southern Italy)
2019
We assessed the relationship between V, Cr, Mn, Hg, As, Cd, Sn, Sb and Pb concentrations in Mytilus galloprovincialis samples from the coasts of Sicily and the expression of metallothioneins. Toxic mineral elements assessment was carried out by A.A. Spectrometry and ICP-MS. The metallothioneins expression was performed by q-PCR method. Low metals' levels were found in the mussel samples examined, in comparison with what was reported in literature. The highest mean values of toxic mineral elements were found in Gela (Cr 0.178 +/- 0.03 mg/Kg, Mn 4.325 +/- 0.012 mg/Kg, As 3.706 +/- 0.009 mg/Kg, Sn 0.148 +/- 0.014 mg/Kg, Sb 0.009 +/- 0.004 mg/Kg e Pb 0.364 +/- 0.01 mg/Kg). Significant levels of…
Zinc and inflammatory/immune response in aging
2007
Life-long antigenic burden determines a condition of chronic inflammation, with increased lymphocyte activation and proinflammatory cytokine production. A large number of studies have documented changes in zinc metabolism in experimental animal models of acute and chronic inflammation and in human chronic inflammatory conditions. In particular, modification of zinc plasma concentration, as well as intracellular disturbance of antioxidant intracellular pathways, has been found in aging and in some age-related diseases. Zinc deficiency is diffused in aged individuals in order to avoid meat and other high zinc content foods due to fear of cholesterol. Rather, they increase the consumption of r…
Response to metals treatment of Fra1, a member of the AP-1 transcription factor family, in P. lividus sea urchin embryos
2018
Abstract Lithium (Li), Nickel (Ni), and Zinc (Zn) are metals normally present in the seawater, although they can have adverse effects on the marine ecosystem at high concentrations by interfering with many biological processes. These metals are toxic for sea urchin embryos, affecting their morphology and developmental pathways. In particular, they perturb differently the correct organization of the embryonic axes (animal-vegetal, dorso-ventral): Li is a vegetalizing agent and Ni disrupts the dorso-ventral axis, while Zn has an animalizing effect. To deeply address the response of Paracentrotus lividus embryos to these metals, we studied the expression profiling of Pl-Fra transcription facto…