Project description:Few works have addressed the effects provoked by the exposure to cadmium containing nanoparticles (NPs) on adult zebrafish (Danio rerio). We studied the effects of CdS NPs (5 nm) or ionic cadmium (10 µg Cd/L) after 3 and 21 d of exposure and at 6 months post-exposure (mpe). Acute toxicity was recorded after exposure to both forms of cadmium. Significant cadmium accumulation was measured in the whole fish after both treatments and autometallography showed a higher accumulation of metal in the intestine than that in the liver. Histopathological alterations, such as inflammation in gills and vacuolization in the liver, were detected after the exposure to both cadmium forms and, in a lower extent, at 6 mpe. X-ray analysis proved the presence of CdS NPs in these organs. The hepatic transcriptome analysis revealed that gene ontology terms such as “immune response” or “actin binding” were over-represented after 21 d of exposure to ionic cadmium respect to CdS NPs treatment. Exposure to CdS NPs caused a significant effect on pathways involved in the immune response and oxidative stress, while the exposure to ionic cadmium affected significantly pathways involved in DNA damage and repair and in the energetic metabolism. Oxidative damage to liver proteins was detected after the exposure to ionic cadmium, while a stronger destabilization of the hepatocyte lysosomal membrane was recorded under exposure to CdS NPs. In summary, although ionic cadmium provoked stronger effects than CdS NPs, both cadmium forms exerted an array of lethal and sublethal effects to zebrafish.
Project description:Obesity is considered as a major public health concern with strong economic and social burdens. Exposure to pollutants such as heavy metals can contribute to the development of obesity and its associated metabolic disorders, including type 2 diabetes and cardiovascular diseases. Adipose tissue is an endocrine and paracrine organ that plays a key role in the development of these diseases and is one of the main target of heavy metal accumulation. In this study, we determined by inductively coupled plasma mass spectrometry cadmium concentrations in human subcutaneous and visceral adipose tissues, ranging between 2.5 nM and 2.5 µM. We found a positive correlation between cadmium levels and age, sex and smoking status and a negative correlation between cadmium and body mass index. Based on cadmium adipose tissue concentrations found in humans, we investigated the effects of cadmium exposure, at concentrations between 1 nM and 10 µM, on adipose-derived human mesenchymal stem cells differentiated into mature adipocytes in vitro. Transcriptomic analysis highlighted that such exposure altered the expression of genes involved in trace element homeostasis and heavy metal detoxification, such as Solute Carrier Family transporters and metallothioneins. This effect correlated with zinc level alteration in cells and cellular media. Interestingly, dysregulation of zinc homeostasis and transporters has been particularly associated with the development of obesity and type 2 diabetes. Moreover, we found that cadmium exposure induces the pro-inflammatory state of the adipocytes by enhancing the expression of genes such as IL-6, IL-1B and CCL2, cytokines also induced in obesity. Finally, cadmium modulates various adipocyte functions such as the insulin response signaling pathway and lipid homeostasis. Collectively, our data identified some of the cellular mechanisms by which cadmium alters adipocyte functions, thus highlighting new facets of its potential contribution to the progression of metabolic disorders.
Project description:Cadmium is a metalloestrogen known to activate the estrogen receptor and promote breast cancer cell growth. Previous studies have implicated cadmium in the development of more malignant tumors; however the molecular mechanisms behind this cadmium-induced malignancy remain elusive. Using clonal cell lines derived by exposing breast cancer cells to cadmium for over 6 month (MCF7-Cd4, -Cd6, -Cd7, -Cd8 and -Cd12), this study aims to identify gene expression signatures associated with chronic cadmium exposure. Our results demonstrate that prolonged exposure does not merely result in the deregulation of genes but actually leads to a distinctive expression profile. The genes deregulated in cadmium-exposed cells are involved in multiple biological processes (i.e cell growth, apoptosis, etc.) and molecular functions (i.e. cadmium/metal ion binding, transcription factor activity, etc). Hierarchical clustering demonstrates that the five clonal cadmium cell lines share a common gene expression signature of breast cancer associated genes, clearly differentiating control from cadmium exposed cells. The results presented in this study offer insights into the cellular and molecular impacts of cadmium on breast cancer carcinogenesis and emphasize the importance of studying chronic cadmium exposure as one possible mechanism of promoting breast cancer progression.
Project description:Cadmium is a metalloestrogen known to activate the estrogen receptor and promote breast cancer cell growth. Previous studies have implicated cadmium in the development of more malignant tumors; however the molecular mechanisms behind this cadmium-induced malignancy remain elusive. Using clonal cell lines derived by exposing breast cancer cells to cadmium for over 6 month (MCF7-Cd4, -Cd6, -Cd7, -Cd8 and -Cd12), this study aims to identify gene expression signatures associated with chronic cadmium exposure. Our results demonstrate that prolonged exposure does not merely result in the deregulation of genes but actually leads to a distinctive expression profile. The genes deregulated in cadmium-exposed cells are involved in multiple biological processes (i.e cell growth, apoptosis, etc.) and molecular functions (i.e. cadmium/metal ion binding, transcription factor activity, etc). Hierarchical clustering demonstrates that the five clonal cadmium cell lines share a common gene expression signature of breast cancer associated genes, clearly differentiating control from cadmium exposed cells. The results presented in this study offer insights into the cellular and molecular impacts of cadmium on breast cancer carcinogenesis and emphasize the importance of studying chronic cadmium exposure as one possible mechanism of promoting breast cancer progression. To understand the effects of chronic cadmium exposure on gene expression in breast cancer, two control MCF7 parental cell lines and five different clonal cadmium-adapted cell lines (MCF7-Cd4, -Cd6, -Cd7, -Cd8, and -Cd12) - previously derived from cells chronically exposed to cadmium - were used for microarray analysis.
Project description:Cadmium accumulation in kidney results in an irreversible chronic toxicity, but the underlying mechanisms are not clear. Transcriptomics assay may provide insight for the involved complex molecular networks. We used Affymetrix RTA arrays to detail the global gene expression profile of kidney tissues of SD rats with chronic exposure to Cadmium, and identified distinct classes of cadmium exposure related mRNA and pathways.
Project description:This study use DNA microarray to examine gene expression in the spleen of mice exposed to cadmium. Mice were exposed via a single subcutaneous injection CdCl2, with spleen harvested at 24h after exposure for microarray analysis. This work provides insight into the mechanistic pathways involved in acute cadmium intoxication, providing a theoretical basis for identifying candidate biomarkers.