1. |
- Alhamdow, Ayman, et al.
(author)
-
Cardiovascular Disease-Related Serum Proteins in Workers Occupationally Exposed to Polycyclic Aromatic Hydrocarbons
- 2019
-
In: Toxicological Sciences. - : Oxford University Press (OUP). - 1096-6080 .- 1096-0929. ; 171:1, s. 235-246
-
Journal article (peer-reviewed)abstract
- Chimney sweeps have higher incidence and mortality of cardiovascular disease (CVD), likely related to their exposure to polycyclic aromatic hydrocarbons (PAH). In order to identify underlying mechanisms of PAH-related CVD, we here investigated whether PAH exposure was associated with levels of putative CVD-related proteins in serum among currently working chimney sweeps. We enrolled 116 chimney sweeps and 125 unexposed controls, all nonsmoking male workers from Sweden. We measured monohydroxylated PAH metabolites in urine by liquid chromatography coupled to tandem mass spectrometry and a panel of 85 proteins in serum using proximity extension assay. Linear regression analysis adjusted for age and body mass index showed that 25 proteins were differentially expressed between chimney sweeps and the controls (p <. 05, adjusted for false discovery rate). Of the 25 proteins, follistatin (FS), prointerleukin-16 (IL-16), and heat shock protein beta-1 (HSP 27) showed positive associations with the monohydroxylated metabolites of PAH in a dose-response manner (p <. 05). Pathway and gene ontology analyses demonstrated that the differentially expressed proteins were mainly involved in inflammatory response and immunological functions, such as leukocyte migration, cell movement of leukocytes, and adhesion of immune cells. In conclusion, we found a number of putative CVD-related proteins differentially expressed, between PAH-exposed and unexposed individuals, and mainly involved in inflammation and immune function. Our data warrant protective measures to reduce PAH exposure and longitudinal investigations of the protein profile in chimney sweeps and other occupational groups exposed to PAH.
|
|
2. |
|
|
3. |
- Gu, J., et al.
(author)
-
Inhibition of Autophagy Alleviates Cadmium-Induced Mouse Spleen and Human B Cells Apoptosis
- 2019
-
In: Toxicological Sciences. - : Oxford University Press (OUP). - 1096-6080 .- 1096-0929. ; 170:1, s. 109-122
-
Journal article (peer-reviewed)abstract
- Cadmium (Cd) is a toxic heavy metal that can accumulate and cause severe damage to many organs, such as liver, kidney, lung, etc. Cd also significantly suppresses immunity, however, the underlying mechanism involved in Cd-induced immunnotoxicity is still unclear. The present study indicated that semichronic Cd exposure (7days) induced apoptotic damage of mouse spleen. In human Ramos B cells, Cd exposure also induced apoptosis, which was dependent on Cd-induced vacuole membrane protein 1 (VMP1) expression and autophagy. Cd-induced autophagy and apoptosis were abated when VMP1 expression was knockdown. In addition, Cd-induced VMP1 expression, autophagy, and apoptosis were dependent on the elevation of Ca2+ and reactive oxygen species (ROS). More important, Cd exposure also induced VMP1 expression and autophagy in mouse spleen tissue, and the intraperitoneal injection of the autophagy inhibitor chloroquine (CQ) into mice effectively reduced Cd-induced spleen apoptotic damage. Taken together, these results indicate Cd-induced autophagy, promotes apoptosis in immune cells, and inhibition of autophagy can alleviate Cd-induced spleen and immune cell apoptosis. This study might provide the groundwork for future studies on Cd-induced immunomodulatory effects and immune diseases.
|
|
4. |
- Hendriks, DFG, et al.
(author)
-
Mechanisms of Chronic Fialuridine Hepatotoxicity as Revealed in Primary Human Hepatocyte Spheroids
- 2019
-
In: Toxicological sciences : an official journal of the Society of Toxicology. - : Oxford University Press (OUP). - 1096-0929. ; 171:2, s. 385-395
-
Journal article (peer-reviewed)abstract
- Drug hepatotoxicity is often delayed in onset. An exemplar case is the chronic nature of fialuridine hepatotoxicity, which resulted in the deaths of several patients in clinical trials as preclinical studies failed to identify this human-specific hepatotoxicity. Conventional preclinical in vitro models are mainly designed to evaluate the risk of acute drug toxicity. Here, we evaluated the utility of 3D spheroid cultures of primary human hepatocytes (PHHs) to assess chronic drug hepatotoxicity events using fialuridine as an example. Fialuridine toxicity was only detectable after 7 days of repeated exposure. Clinical manifestations, including reactive oxygen species formation, lipid accumulation, and induction of apoptosis, were readily identified. Silencing the expression or activity of the human equilibrative nucleoside transporter 1 (ENT1), implicated in the mitochondrial transport of fialuridine, modestly protected PHH spheroids from fialuridine toxicity. Interference with the phosphorylation of fialuridine into the active triphosphate metabolites by silencing of thymidine kinase 2 (TK2) provided substantial protection, whereas simultaneous silencing of ENT1 and TK2 provided near-complete protection. Fialuridine-induced mitochondrial dysfunction was suggested by a decrease in the expression of mtDNA-encoded genes, which correlated with the onset of toxicity and was prevented under the simultaneous silencing of ENT1 and TK2. Furthermore, interference with the expression or activity of ribonucleotide reductase (RNR), which is critical to deoxyribonucleoside triphosphate (dNTP) pool homeostasis, resulted in selective potentiation of fialuridine toxicity. Our findings demonstrate the translational applicability of the PHH 3D spheroid model for assessing drug hepatotoxicity events which manifest only under chronic exposure conditions.
|
|
5. |
- Holmgren, Gustav, 1983-, et al.
(author)
-
Expression Profiling of Human Pluripotent Stem Cell-Derived Cardiomyocytes Exposed to Doxorubicin-Integration and Visualization of Multi-Omics Data
- 2018
-
In: Toxicological Sciences. - : Oxford University Press (OUP). - 1096-6080 .- 1096-0929. ; 163:1, s. 182-195
-
Journal article (peer-reviewed)abstract
- Anthracyclines, such as doxorubicin, are highly efficient chemotherapeutic agents against a variety of cancers. However, anthracyclines are also among the most cardiotoxic therapeutic drugs presently on the market. Chemotherapeutic-induced cardiomyopathy is one of the leading causes of disease and mortality in cancer survivors. The exact mechanisms responsible for doxorubicin-induced cardiomyopathy are not completely known, but the fact that the cardiotoxicity is dose-dependent and that there is a variation in time-to-onset of toxicity, and gender- and age differences suggests that several mechanisms may be involved. In this study, we investigated doxorubicin-induced cardiotoxicity in human pluripotent stem cell-derived cardiomyocytes using proteomics. In addition, different sources of omics data (protein, mRNA, and microRNA) from the same experimental setup were further combined and analyzed using newly developed methods to identify differential expression in data of various origin and types. Subsequently, the results were integrated in order to generate a combined visualization of the findings. In our experimental model system, we exposed cardiomyocytes derived from human pluripotent stem cells to doxorubicin for up to 2 days, followed by a wash-out period of additionally 12 days. Besides an effect on the cell morphology and cardiomyocyte functionality, the data show a strong effect of doxorubicin on all molecular levels investigated. Differential expression patterns that show a linkage between the proteome, transcriptome, and the regulatory microRNA network, were identified. These findings help to increase the understanding of the mechanisms behind anthracycline-induced cardiotoxicity and suggest putative biomarkers for this condition.
|
|
6. |
|
|
7. |
- Kia, Richard, et al.
(author)
-
MicroRNA-122 : a novel hepatocyte-enriched in vitro marker of drug-induced cellular toxicity
- 2015
-
In: Toxicological Sciences. - : Oxford University Press. - 1096-6080 .- 1096-0929. ; 144:1, s. 173-185
-
Journal article (peer-reviewed)abstract
- Emerging hepatic models for the study of drug-induced toxicity include pluripotent stem cell-derived hepatocyte-like cells (HLCs) and complex hepatocyte-non-parenchymal cellular coculture to mimic the complex multicellular interactions that recapitulate the niche environment in the human liver. However, a specific marker of hepatocyte perturbation, required to discriminate hepatocyte damage from non-specific cellular toxicity contributed by non-hepatocyte cell types or immature differentiated cells is currently lacking, as the cytotoxicity assays routinely used in in vitro toxicology research depend on intracellular molecules which are ubiquitously present in all eukaryotic cell types. In this study, we demonstrate that microRNA-122 (miR-122) detection in cell culture media can be used as a hepatocyte-enriched in vitro marker of drug-induced toxicity in homogeneous cultures of hepatic cells, and a cell-specific marker of toxicity of hepatic cells in heterogeneous cultures such as HLCs generated from various differentiation protocols and pluripotent stem cell lines, where conventional cytotoxicity assays using generic cellular markers may not be appropriate. We show that the sensitivity of the miR-122 cytotoxicity assay is similar to conventional assays that measure lactate dehydrogenase activity and intracellular adenosine triphosphate when applied in hepatic models with high levels of intracellular miR-122, and can be multiplexed with other assays. MiR-122 as a biomarker also has the potential to bridge results in in vitro experiments to in vivo animal models and human samples using the same assay, and to link findings from clinical studies in determining the relevance of in vitro models being developed for the study of drug-induced liver injury.
|
|
8. |
- Kirla, K. T., et al.
(author)
-
From the Cover: Zebrafish Larvae Are Insensitive to Stimulation by Cocaine: Importance of Exposure Route and Toxicokinetics
- 2016
-
In: Toxicological Sciences. - : Oxford University Press (OUP). - 1096-6080 .- 1096-0929. ; 154:1, s. 183-193
-
Journal article (peer-reviewed)abstract
- Zebrafish (Danio rerio) larvae have been suggested as vertebrate model to complement or even replace mammals for rapidly assessing behavioral effects of psychoactive drugs. Yet, divergent responses have been reported in mammals and fish despite the conservation of many drug targets. Cocaine, eg, acts as stimulant in mammals but no such response has been documented for zebrafish larvae. We hypothesized that differences in exposure routes (inhalation or injection in mammals vs waterborne in fish) may be a reason for differences in behavioral responses. We characterized cocaine toxicokinetics by liquid chromatography-mass spectrometry and found its rapid uptake into larvae. We used Matrix-assisted laser desorption ionization-mass spectrometry imaging for the first time to characterize internal distribution of cocaine in zebrafish larvae. Surprisingly, eyes accumulated the highest amount of cocaine and retained most of it even after 48 h depuration. We attribute this to trapping by pigment melanin, a thus far little explored mechanism that may also be relevant for other basic drugs. Cocaine also reached the brain but with levels similar to those in trunk indicating simple passive diffusion as means of distribution which was supported by toxicokinetic models. Although brain levels covered those known to cause hyperactivity in mammals, only hypoactivity (decreased locomotion) was recorded in zebrafish larvae. Our results therefore point to cocaine's anesthetic properties as the dominant mechanism of interaction in the fish: upon entry through the fish skin and gills, it first acts on peripheral nerves rapidly overriding any potential stimulatory response in the brain.
|
|
9. |
- Lamore, SD, et al.
(author)
-
Deconvoluting Kinase Inhibitor Induced Cardiotoxicity
- 2017
-
In: Toxicological sciences : an official journal of the Society of Toxicology. - : Oxford University Press (OUP). - 1096-0929. ; 158:1, s. 213-226
-
Journal article (peer-reviewed)
|
|
10. |
|
|
11. |
|
|
12. |
- Machtinger, Ronit, et al.
(author)
-
Placental lncRNA Expression Is Associated With Prenatal Phthalate Exposure
- 2018
-
In: Toxicological Sciences. - : Oxford University Press (OUP). - 1096-6080 .- 1096-0929. ; 163:1, s. 116-122
-
Journal article (peer-reviewed)abstract
- Phthalates are endocrine-disrupting chemicals that can cross the placenta and affect the fetal epigenome. Among various epigenetic regulators of gene expression, long noncoding RNAs (lncRNAs) are important players that may also be involved in the manifestation of endocrine-disrupting chemical toxicity. We sought to explore the association between maternal urinary phthalate metabolite concentrations and lncRNA expression in human placenta to better understand potential mechanisms through which lncRNAs participate in mediating phthalate toxicity. Ten patients with uncomplicated dichorionic diamniotic twin pregnancies at term were included in this study. Urinary (n = 10) and placenta samples (n = 20) were collected for all participants. Urinary samples were analyzed for 15 phthalate metabolites and 2 phthalate alternative metabolites. Real-time PCR arrays were used to identify and quantify 87 lncRNAs from the placental samples. We tested the Spearman correlation matrix to compare prenatal phthalate measures against placental lncRNA levels. lncRNA levels showed large variations across samples, with no significant differences in lncRNA expression within twin pairs. Mono-(carboxynonyl) phthalate demonstrated consistently strong correlations with most lncRNAs. The strongest correlation was observed between mono-hydroxyisobutyl phthalate and LOC91450 (Rspearman = 0.88, p < .001). This correlation remained significant after Bonferroni adjustment. Other strong correlations were observed between mono-isobutyl phthalate, DPP10 and HOTTIP (Rspearman = −0.91, p < .001). AIRN, DACT3.AS1, DLX6, DPP10, HOTTIP, LOC143666, and LOC91450 were strongly correlated with the greatest number of phthalate metabolites. Further studies are needed to validate these results and understand if the altered expression of lncRNAs in human placenta has clinical significance.
|
|
13. |
|
|
14. |
|
|
15. |
- Philippot, Gaetan, et al.
(author)
-
A Cannabinoid Receptor Type 1 (CB1R) Agonist Enhances the Developmental Neurotoxicity of Acetaminophen (Paracetamol)
- 2018
-
In: Toxicological Sciences. - : OXFORD UNIV PRESS. - 1096-6080 .- 1096-0929. ; 166:1, s. 203-212
-
Journal article (peer-reviewed)abstract
- Acetaminophen (AAP; also known as paracetamol) is the most used and only recommended analgesic and antipyretic among pregnant women and young children. However, recent findings in both humans and rodents suggest a link between developmental exposure to AAP and adverse neurobehavioral effects later in life. We hypothesized that the cannabinoid receptor type 1 (CB1R) may be involved in the developmental neurotoxicity of AAP, owing to its interaction with the endocannabinoid system. Here we test if CB1R agonist WIN 55 212-2 (WIN) and AAP can interact when exposure occurs during a neurodevelopmental stage known for increased growth rate and for its vulnerability to AAP exposure. We exposed male NMRI mice on postnatal day 10 to different combinations of AAP and WIN. Adult mice, neonatally co-exposed to AAP and WIN, displayed a significant lack of habituation in the spontaneous behavior test, when compared with controls and single agent exposed mice. These adult adverse effects may at least in part be explained by a reduction of transcript levels of hippocampal synaptophysin (Syp) and tropomyosin receptor kinase B (Trkb), and cerebral cortical fatty acid amide hydroxylase (Faah), 24h after exposure. These findings are consistent with our hypothesis that AAP and WIN can interact when exposure occurs during early postnatal brain development in mice. Assuming our results are relevant for humans, they raise concerns on AAP safety because it is the only recommended analgesic and antipyretic during pregnancy and early life.
|
|
16. |
- Qiu, Lin, 2000, et al.
(author)
-
Acute and Long-Term Effects of Brief Sevoflurane Anesthesia During the Early Postnatal Period in Rats
- 2016
-
In: Toxicological Sciences. - : Oxford University Press (OUP). - 1096-6080 .- 1096-0929. ; 149:1, s. 121-133
-
Journal article (peer-reviewed)abstract
- The possibility that exposure to general anesthetics during early life results in long-term impairment of neural function attracted considerable interest over the past decade. Extensive laboratory data suggest that administration of these drugs during critical stages of central nervous system development can lead to cell death, impaired neurogenesis, and synaptic growth as well as cognitive deficits. These observations are corroborated by several recent human epidemiological studies arguing that such cognitive impairment might also occur in humans. Despite the potential public health importance of this issue, several important questions remain open. Amongst them, how the duration of anesthesia exposure impact on outcome is as yet not fully elucidated. To gain insight into this question, here we focused on the short- and long-term impact of a 30-min-long exposure to clinically relevant concentrations of sevoflurane in rat pups at 2 functionally distinct stages of the brain growth spurt. We show that this treatment paradigm induced developmental stage-dependent and brain region-specific acute but not lasting changes in dendritic spine densities. Electrophysiological recordings in hippocampal brain slices from adult animals exposed to anesthesia in the early postnatal period revealed larger paired-pulse facilitation but no changes in the long-term potentiation paradigm when compared with nonanesthetized controls. 5-bromo-2-deoxyuridine pulse and pulse-chase experiments demonstrated that neither proliferation nor differentiation and survival of hippocampal progenitors were affected by sevoflurane exposure. In addition, behavioral testing of short- and long-term memory showed no differences between control and sevoflurane-exposed animals. Overall, these results suggest that brief sevoflurane exposure during critical periods of early postnatal development, although it does not seem to exert major long-term effects on brain circuitry development, can induce subtle changes in synaptic plasticity and spine density of which the physiological significance remains to be determined.
|
|
17. |
- Sand, Salomon, et al.
(author)
-
Dose-Related Severity Sequence, and Risk-Based Integration, of Chemically Induced Health Effects
- 2018
-
In: Toxicological Sciences. - : OXFORD UNIV PRESS. - 1096-6080 .- 1096-0929. ; 165:1, s. 74-89
-
Journal article (peer-reviewed)abstract
- Risk assessment of chemical hazards is typically based on single critical health effects. This work aims to expand the current approach by characterizing the dose-related sequence of the development of multiple (lower- to higher-order) toxicological health effects caused by a chemical. To this end a "reference point profile" is defined as the relation between benchmark doses for considered health effects, and a standardized severity score determined for these effects. For a given dose of a chemical or mixture the probability for exceeding the reference point profile, thereby provoking lower- to higher-order effects, can be assessed. The overall impact at the same dose can also be derived by integrating contributions across all health effects following severity-weighting. In its generalized form the new impact metric relates to the probability of response for the most severe health effects. Reference points (points of departure) corresponding to defined levels of response can also be estimated. The proposed concept, which is evaluated for dioxin-like chemicals, provides an alternative for characterizing the low-dose region below the reference point for a severe effect like cancer. The shape and variability of the reference point profile add new dimensions to risk assessment, which for example extends the characterization of chemical potency, and the concept of acceptable effect sizes for individual health effects. Based on the present data the method shows high stability at low doses/responses, and is also robust to differences in severity categorization of effects. In conclusion, the novel method proposed enables risk-based integration of multiple dose-related health effects. It provides a first step towards a more comprehensive characterization of chemical toxicity, and suggests a potential for improved low-dose risk assessment.
|
|
18. |
|
|
19. |
- Shabalina, Irina G., et al.
(author)
-
The Environmental Pollutants Perfluorooctane Sulfonate and Perfluorooctanoic Acid Upregulate Uncoupling Protein 1 (UCP1) in Brown-Fat Mitochondria Through a UCP1-Dependent Reduction in Food Intake
- 2015
-
In: Toxicological Sciences. - : Oxford University Press (OUP). - 1096-6080 .- 1096-0929. ; 146:2, s. 334-343
-
Journal article (peer-reviewed)abstract
- The environmental pollutants perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) cause a dramatic reduction in the size of the major adipose tissue depots and a general body weight decrease when they are added to the food of mice. We demonstrate here that this is mainly due to a reduction in food intake; this reduction was not due to food aversion. Remarkably and unexpectedly, a large part of the effect of PFOA/PFOS on food intake was dependent on the presence of the uncoupling protein 1 (UCP1) in the mice. Correspondingly, PFOA/PFOS treatment induced recruitment of brown adipose tissue mitochondria: increased oxidative capacity and increased UCP1-mediated oxygen consumption (thermogenesis). In mice pair-fed to the food intake during PFOA/PFOS treatment in wildtype mice, brown-fat mitochondrial recruitment was also induced. We conclude that we have uncovered the existence of a regulatory component of food intake that is dependent upon brown adipose tissue thermogenic activity. The possible environmental consequences of this novel PFOA/PFOS effect (a possible decreased fitness) are noted, as well as the perspectives of this finding on the general understanding of control of food intake control and its possible extension to combatting obesity.
|
|
20. |
|
|
21. |
|
|
22. |
|
|
23. |
- Vorojeikina, Daria, et al.
(author)
-
Glutathione S-transferase activity moderates methylmercury toxicity during development in Drosophila
- 2017
-
In: Toxicological Sciences. - : Oxford University Press (OUP). - 1096-6080 .- 1096-0929. ; 157:1, s. 211-221
-
Journal article (peer-reviewed)abstract
- Glutathione (GSH) pathways play a central role in methylmercury (MeHg) metabolismand elimination, largely due to formation of a more readily transported MeHg-GSH conjugate. Glutathione S-transferases (GSTs) have therefore been proposed to facilitate MeHg elimination by catalyzing MeHg-GSH conjugation. A role for human GSTP1 in MeHg disposition is suggested by the association of two common polymorphisms in the coding region (Ile105Val and Ala114Val) with Hg levels in either blood or hair. In this study, we investigated a functional role for GSTs in modulating MeHg toxicity during development. Using the Drosophila model to execute targeted manipulations of both endogenous GSTs and introduced human GSTP1 variants we correlate gene and protein expression levels with GST activity and also with MeHg body burden and developmental outcomes. RNAi knockdown of endogenous GSTD1, GSTE1, or GSTS1, individually, increased susceptibility to MeHg during pupal development resulting in a reduced rate of adult eclosion. Exogenous expression of human GSTP1 in developing flies resulted in increased MeHg tolerance relative to control flies as seen with elevated eclosion rates when reared on MeHg containing food. Furthermore, the GSTP1105 and GSTP1114 variants showed a reduced enzyme activity relative to wild-type GSTP1 (GSTP1wt). Finally, we observed a trend whereby Hg body burden was inversely related to the levels of GST activity. However, in some instances GSTP1 expression resulted in increased eclosion rates without reducing Hg body burden suggesting that GSTs interact with MeHg via both toxicokinetic and toxicodynamic mechanisms. These findings indicate that GSTs moderate MeHg toxicity during development in our experimental model.
|
|
24. |
|
|
25. |
- Wahlberg, Karin E, et al.
(author)
-
Common polymorphisms in the solute carrier SLC30A10 are associated with blood manganese and neurological function.
- 2016
-
In: Toxicological Sciences. - : Oxford University Press (OUP). - 1096-0929 .- 1096-6080. ; 149:2, s. 473-483
-
Journal article (peer-reviewed)abstract
- Manganese (Mn) is an essential nutrient in humans, but excessive exposure to Mn may cause neurotoxicity. Despite homeostatic regulation, Mn concentrations in blood vary considerably among individuals. We evaluated if common single-nucleotide polymorphisms (SNPs) in SLC30A10, which likely encodes a Mn transporter, influence blood Mn concentrations and neurological function. We measured blood Mn concentrations by ICP-MS or atomic absorption spectroscopy and genotyped two SLC30A10 non-coding SNPs (rs2275707 and rs12064812) by TaqMan PCR in cohorts from Bangladesh (N=406), the Argentinean Andes (N=198), and Italy (N=238). We also measured SLC30A10 expression in whole blood by TaqMan PCR in a sub-group (N=101) from the Andean cohort, and neurological parameters (sway velocity and finger-tapping speed) in the Italian cohort.The rs2275707 variant allele was associated with increased Mn concentrations in the Andes (8%, p=0.027) and Italy (10.6%, p=0.012), but not as clear in Bangladesh (3.4%, p=0.21; linear regression analysis adjusted for age, gender, and plasma ferritin). This allele was also associated with increased sway velocity (15%, p=0.033; adjusted for age and sex) and reduced SLC30A10 expression (-24.6%, p=0.029). By contrast, the rs12064812 variant homozygous genotype was associated with reduced Mn concentrations, particularly in the Italian cohort (-18.4%, p=0.04), and increased finger-tapping speed (8.7%, p=0.025).We show that common SNPs in SLC30A10 are associated with blood Mn concentrations in three unrelated cohorts and that their influence may be mediated by altered SLC30A10 expression. Moreover, the SNPs appeared to influence neurological functions independent of blood Mn concentrations, suggesting that SLC30A10 could regulate brain Mn levels.
|
|