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Increased liver somatic index and plasma Apo A-I levels in rats exposed to Bisphenol A
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Abstracts / Toxicology Letters 211S (2012) S43–S216
elongated spindle-like morphology, as well as apoptotic and early apoptotic cells were seen. EnnB reduced cellular ability to capture and internalize receptors as illustrated by the lipid marker ganglioside GM1. Furthermore, transmission electron microscopic (TEM) pictures revealed accumulation of lipids inside of the lysosomes forming lamellar structures/myelin bodies, suggesting induced lysosomal damage. Enhanced levels of activated caspase-1 were observed after EnnB exposure, and pre-treatment with the caspase1 specific inhibitor, ZYVAD-FMK reduced EnnB-induced apoptosis. EnnB increased the release of interleukin-1beta (IL-1) in cells primed with lipopolysaccharide (LPS). ZYVAD-FMK, as well as the cathepsin B inhibitor CA-074Me reduced the IL- release. In conclusion, we suggest that EnnB may activate the inflammasome through lysosomal damage, leakage of cathepsin B and cleavage of caspase-1, resulting in apoptosis as well as processing and release of IL-1. doi:10.1016/j.toxlet.2012.03.489
P20-09 Identification of novel biomarkers of mercury-induced immune dysregulation Jennifer Nyland 1 , Jonathan Motts 1 , Renee Gardner 2 , Ellen Silbergeld 3 University of South Carolina, United States, 2 Karolinska Institute, Sweden, 3 Johns Hopkins University, United States
1
Purpose: Mercury (Hg) is an ubiquitous environmental contaminant, causing both neurotoxicity and immunotoxicity. The goal of this project was to identify novel serum biomarkers of Hg-induced immune dysregulation in humans. Methods: An analysis of serum samples from an epidemiological study on miners working in Amazonian Brazil was completed on stratified samples (based on Hg level and antinuclear autoantibody titer) using a protein microarray to probe for the induction of elevated autoantibodies. These auto-antibodies were then analyzed in terms of immune system pathways. Pathways examined include those involved in antigen presentation, oxidative stress, and macrophage signaling/activation. Results and conclusions: We found statistically significant correlations between high levels of Hg exposure and positivity for certain auto-antibodies. Auto-antibodies identified as potential novel biomarkers include antibodies to the following proteins: interferon induced transmembrane protein (IFITM-1), heat shock transcription factor (HSF-1), colony stimulating factor (CSF-1), ghrelin/obestatin prepropeptide (GHRL), metallopeptidase inhibitor (TIMP-1), peroxiredoxin (PRDX-2), glutathione S-transferase alpha (GSTA-1), and chaperonin (HSPD-1). These proteins play a wide variety of roles, including as antioxidants, in the regulation of pro- and anti-inflammatory cytokines, as well as danger and oxidative stress signaling. Dysregulation of these proteins is believed to play a role in autoimmune diseases such as rheumatoid arthritis, Sjögren’s syndrome, and multiple sclerosis. Our next step is to validate these findings by probing the entire sample cohort for titers of these auto-antibodies. doi:10.1016/j.toxlet.2012.03.490
P20-10 Increased liver somatic index and plasma Apo A-I levels in rats exposed to Bisphenol A Helen Karlsson 1 , Monika Rönn 2 , Stefan Ljunggren 3 , Lars Lind 4 , P.M. Lind 2 1
County Council Ostergotland, Sweden, 2 Occupational and Environmental Medicine, Sweden, 3 Center of Occupational and Environmental, Sweden, 4 Department of Medical Sciences, Uppsala, Sweden Increased knowledge about harmful effects of environmental contaminants such as endocrine disruptors and elucidation of their mechanisms of action in biological systems are of significant importance for optimal preventive guidance regarding human health. In this study female rats were fed with addition of fructose (5%) and different doses of Bisphenol A (fructose 5% + 0.025, 0.25 and 2.5 mg/L respectively) for 10 weeks in purpose to investigate, among others, effects on plasma lipids, liver somatic index, insulin, adiponektin, leptin and blood glucose levels. Insulin, adiponektin, leptin and blood glucose levels were measured by Elisa. Plasma apo A-I was separated by SDS PAGE and protein intensities were evaluated after Western Blot. After 10 weeks, no significant differences regarding insulin, adiponektin, leptin and blood glucose levels were detected. On the other hand, rats fed with fructose plus BPA (low, medium and high dose) had significantly raised plasma apo A-I levels compared to control rats. Interestingly, the apo A-I levels correlated positively with the LSI (% of total weight, p = 0.014) while the mean total cholesterol levels did not follow the apo A-I and LSI trend in the BPA fed groups. Our results indicate a role of apo A-I in immune defence. We suggest that apo A-I may act as a scavenger by interaction with BPA followed by clearance via the liver. doi:10.1016/j.toxlet.2012.03.491
P20-11 Comparative immunotoxicity study of single-walled carbon nanotubes Soyoung Lee, Sang-Hyun Kim Kyungpook National University, Republic of Korea Purpose: Studies on the single-walled carbon nanotubes (swCNTs) are becoming popular, not only for their promising application in the electronics, optics, and mechanical materials, but also in biological applications, such as imaging and drug delivery. However, its safety of swCNTs has not yet been fully investigated. Since swCNTs will be more likely to be used in biomedical applications, the investigation and elucidation of cellular effects and the associated molecular mechanism are urgently needed. In the present study, we investigated the interrelationship between different swCNTs properties (such as functionalization and dispersion) and immunotoxic effects, and defined underlying mechanisms of action. Methods: We used in vitro cell culture system for immunotoxicity of swCNTs using MTT assay, ROS production, SOD activity and confocal microscope observation in macrophages. Results and conclusions: The swCNTs samples were composed of different functionalization including swCNT, swCNT-COOH, swCNT-OH, and swCNT-NH2. As observed in the MTT and NO assay, swCNT-COOH induced much greater cytotoxicity than other functionalized swCNTs in macrophages. This is because swCNT-COOH showed significantly enhanced cellular uptake and thus, increased ROS production than
Abstracts / Toxicology Letters 211S (2012) S43–S216
elongated spindle-like morphology, as well as apoptotic and early apoptotic cells were seen. EnnB reduced cellular ability to capture and internalize receptors as illustrated by the lipid marker ganglioside GM1. Furthermore, transmission electron microscopic (TEM) pictures revealed accumulation of lipids inside of the lysosomes forming lamellar structures/myelin bodies, suggesting induced lysosomal damage. Enhanced levels of activated caspase-1 were observed after EnnB exposure, and pre-treatment with the caspase1 specific inhibitor, ZYVAD-FMK reduced EnnB-induced apoptosis. EnnB increased the release of interleukin-1beta (IL-1) in cells primed with lipopolysaccharide (LPS). ZYVAD-FMK, as well as the cathepsin B inhibitor CA-074Me reduced the IL- release. In conclusion, we suggest that EnnB may activate the inflammasome through lysosomal damage, leakage of cathepsin B and cleavage of caspase-1, resulting in apoptosis as well as processing and release of IL-1. doi:10.1016/j.toxlet.2012.03.489
P20-09 Identification of novel biomarkers of mercury-induced immune dysregulation Jennifer Nyland 1 , Jonathan Motts 1 , Renee Gardner 2 , Ellen Silbergeld 3 University of South Carolina, United States, 2 Karolinska Institute, Sweden, 3 Johns Hopkins University, United States
1
Purpose: Mercury (Hg) is an ubiquitous environmental contaminant, causing both neurotoxicity and immunotoxicity. The goal of this project was to identify novel serum biomarkers of Hg-induced immune dysregulation in humans. Methods: An analysis of serum samples from an epidemiological study on miners working in Amazonian Brazil was completed on stratified samples (based on Hg level and antinuclear autoantibody titer) using a protein microarray to probe for the induction of elevated autoantibodies. These auto-antibodies were then analyzed in terms of immune system pathways. Pathways examined include those involved in antigen presentation, oxidative stress, and macrophage signaling/activation. Results and conclusions: We found statistically significant correlations between high levels of Hg exposure and positivity for certain auto-antibodies. Auto-antibodies identified as potential novel biomarkers include antibodies to the following proteins: interferon induced transmembrane protein (IFITM-1), heat shock transcription factor (HSF-1), colony stimulating factor (CSF-1), ghrelin/obestatin prepropeptide (GHRL), metallopeptidase inhibitor (TIMP-1), peroxiredoxin (PRDX-2), glutathione S-transferase alpha (GSTA-1), and chaperonin (HSPD-1). These proteins play a wide variety of roles, including as antioxidants, in the regulation of pro- and anti-inflammatory cytokines, as well as danger and oxidative stress signaling. Dysregulation of these proteins is believed to play a role in autoimmune diseases such as rheumatoid arthritis, Sjögren’s syndrome, and multiple sclerosis. Our next step is to validate these findings by probing the entire sample cohort for titers of these auto-antibodies. doi:10.1016/j.toxlet.2012.03.490
P20-10 Increased liver somatic index and plasma Apo A-I levels in rats exposed to Bisphenol A Helen Karlsson 1 , Monika Rönn 2 , Stefan Ljunggren 3 , Lars Lind 4 , P.M. Lind 2 1
County Council Ostergotland, Sweden, 2 Occupational and Environmental Medicine, Sweden, 3 Center of Occupational and Environmental, Sweden, 4 Department of Medical Sciences, Uppsala, Sweden Increased knowledge about harmful effects of environmental contaminants such as endocrine disruptors and elucidation of their mechanisms of action in biological systems are of significant importance for optimal preventive guidance regarding human health. In this study female rats were fed with addition of fructose (5%) and different doses of Bisphenol A (fructose 5% + 0.025, 0.25 and 2.5 mg/L respectively) for 10 weeks in purpose to investigate, among others, effects on plasma lipids, liver somatic index, insulin, adiponektin, leptin and blood glucose levels. Insulin, adiponektin, leptin and blood glucose levels were measured by Elisa. Plasma apo A-I was separated by SDS PAGE and protein intensities were evaluated after Western Blot. After 10 weeks, no significant differences regarding insulin, adiponektin, leptin and blood glucose levels were detected. On the other hand, rats fed with fructose plus BPA (low, medium and high dose) had significantly raised plasma apo A-I levels compared to control rats. Interestingly, the apo A-I levels correlated positively with the LSI (% of total weight, p = 0.014) while the mean total cholesterol levels did not follow the apo A-I and LSI trend in the BPA fed groups. Our results indicate a role of apo A-I in immune defence. We suggest that apo A-I may act as a scavenger by interaction with BPA followed by clearance via the liver. doi:10.1016/j.toxlet.2012.03.491
P20-11 Comparative immunotoxicity study of single-walled carbon nanotubes Soyoung Lee, Sang-Hyun Kim Kyungpook National University, Republic of Korea Purpose: Studies on the single-walled carbon nanotubes (swCNTs) are becoming popular, not only for their promising application in the electronics, optics, and mechanical materials, but also in biological applications, such as imaging and drug delivery. However, its safety of swCNTs has not yet been fully investigated. Since swCNTs will be more likely to be used in biomedical applications, the investigation and elucidation of cellular effects and the associated molecular mechanism are urgently needed. In the present study, we investigated the interrelationship between different swCNTs properties (such as functionalization and dispersion) and immunotoxic effects, and defined underlying mechanisms of action. Methods: We used in vitro cell culture system for immunotoxicity of swCNTs using MTT assay, ROS production, SOD activity and confocal microscope observation in macrophages. Results and conclusions: The swCNTs samples were composed of different functionalization including swCNT, swCNT-COOH, swCNT-OH, and swCNT-NH2. As observed in the MTT and NO assay, swCNT-COOH induced much greater cytotoxicity than other functionalized swCNTs in macrophages. This is because swCNT-COOH showed significantly enhanced cellular uptake and thus, increased ROS production than