Hexabromocyclododecane (HBCD) induced changes in the liver proteome of eu- and hypothyroid female rats

The brominated flame retardant tetrabromobisphenol A-bis(2,3-dibromo-2-methylpropyl ether) as well as hexabromocyclododecane lead to lipid disorders in mice

The brominated flame retardant tetrabromobisphenol A-bis(2,3-dibromo-2-methylpropyl ether) (TBBPA-DBMPE) is a recommended substitute for hexabromocyclododecane (HBCD), a banned persistent organic pollutant, yet its potential toxicities remains largely unexplored. Here, we investigated the effects of a long-term exposure to TBBPA-DBMPE at nominal doses of 50 and 1000 μg/kg/d on lipid homeostasis in CD-1 mice, in comparison with 50 μg/kg/d HBCD as a positive control. Male pups received chemical treatments through maternal administration via drinking water from postnatal day 0-21, followed by direct administration through drinking water after weaning. On the 23rd week after treatment, the oral lipid tolerance test revealed that low-dose TBBPA-DBMPE as well as HBCD affected lipid tolerance, although the fasting serum triglyceride (TG) levels were not altered. When chemical treatment was extended to the 32nd week, TBBPA-DBMPE-treated animals displayed adipocyte hypertrophy in both white adipose tissue (eWAT) and brown adipose tissue (BAT) and hepatic steatosis, which was largely consistent with the effects of HBCD. These findings indicate that like HBCD, TBBPA-DBMPE led to increased lipid load in mice. Interestingly, we also observed intestinal histological changes, coupled with increased expression of lipid absorption-related genes in both HBCD and TBBPA-DBMPE treatments, suggesting increased lipid absorption. This was supported by in vitro findings that both HBCD and TBBPA-DBMPE promoted lipid accumulation in IEC-6 cells under the stress of oleic acid for 6 h, implying that altered lipid absorption by the intestine may partly contributed to increased lipid load in mice. Overall, the effects of 50 μg/kg/d TBBPA-DBMPE in terms of some parameters were comparable with 50 μg/kg/d HBCD, suggesting that TBBPA-DBMPE may not be an ideal substitute of HBCD.

Hexabromocyclododecane (HBCD) induced PANoptosis of chondrocytes via activation of the NLRP3 inflammasome and decreased the exercise ability of mice in vivo

Hexabromocyclododecane (HBCD) is a persistent organic pollutant (POP). HBCD is found in the blood and tissues of most populations and causes a range of toxicological damage to tissues and cells. However, the toxicological effects of HBCD on chondrocytes are not fully understood. Here, we evaluated the toxicological effects of HBCD on chondrocytes and cartilaginous tissue. For this, a model of primary cartilage cells was established. Chondrocytes were exposed to different concentrations of HBCD. Western blot, indirect immunofluorescence, ELISA and other biochemical experiments were performed to analyze the toxicological effects of HBCD on chondrocytes/articular cartilage tissue. Cell proliferation assays showed that HBCD caused a reduction in the proliferative capacity of chondrocytes, and further work indicated that HBCD induces chondrocyte death. Further experiments demonstrated that HBCD caused an inflammatory response in chondrocytes by evaluating the levels of inflammatory factors. We found that HBCD led to PANoptosis in chondrocytes by detecting panapoptosis-related marker molecules, and experimental data indicated that apoptosis markers (cleaved caspase-3/7), pyroptosis markers (caspase-1/GSDMD-N) and necroptosis markers (pMLKL/RIPK3) were upregulated after HBCD treatment. Subsequent experiments illustrated that HBCD activated the DAMP sensor NLRP3, which then mediated ZBP1-induced PANoptosis. In the in vivo model, the experimental animals were administered HBCD at 25, 50 and 100 µg/kg/week for 15 weeks. We found that HBCD led to an inflammatory response in articular cartilage tissue. The safranin O-fast green assay showed a certain degree of damage to cartilage tissue under HBCD treatment. Furthermore, HBCD resulted in an increase in MMP13 expression and a downregulation of COL2 expression in chondrocytes/cartilaginous tissues. HBCD decreased the exercise ability of mice in vivo. These data indicate that HBCD leads to chondrocyte damage. In summary, this study lays the foundation for further exploration of the toxicological effects of HBCD on bone and joints.

Occurrence and Health Effects of Hexabromocyclododecane: An Updated Review

Hexabromocyclododecane (HBCD) is a non-aromatic compound belonging to the bromine flame retardant family and is a known persistent organic pollutant (POP). This compound accumulates easily in the environment and has a high half-life in water. With a variety of uses, the HBCD is found in house dust, electronics, insulation, and construction. There are several isomers and the most studied are α-, β-, and γ-HBCD. Initially used as a substitute for other flame retardants, the polybrominated diphenyl ethers (PBDEs), the discovery of its role as a POP made HBCD use and manufacturing restricted in Europe and other countries. The adverse effects on the environment and human health have been piling, either as a result from its accumulation or considering its power as an endocrine disruptor (ED). Furthermore, it has also been proven that it has detrimental effects on the neuronal system, endocrine system, cardiovascular system, liver, and the reproductive system. HBCD has also been linked to cytokine production, DNA damage, increased cell apoptosis, increased oxidative stress, and reactive oxygen species (ROS) production. Therefore, this review aims to compile the most recent studies regarding the negative effects of this compound on the environment and human health, describing the possible mechanisms by which this compound acts and its possible toxic effects.

Occurrence, Spatial Distribution and Health Risk of Hexabromocyclododecane (HBCD) in Source Water in the Lower Yangtze River, China

The occurrence and health risk of hexabromocyclododecane (HBCD), a brominated flame retardant with its three diastereoisomers, in drinking water sources in the lower Yangtze River in China was investigated. Its concentration ranged from 0.58 to 3.71 ng/L and averaged at 1.18 ng/L. Among the three diastereoisomers of α-, β- and γ-HBCD, γ-HBCD was the dominant one accounting for 44% (ranging 27-82%) to the total concentration. Source of HBCD in the contaminated site was discussed according to its spatial distribution and diastereoisomer profile. The margin of exposure (MOE) approach was applied to evaluate the health risk of HBCD through drinking water by estimated exposure and derived reference dose. The MOE was 17 for adults and 12 for children in the worst-case scenario, suggesting a trivial health concern.

Studying the Impact of Persistent Organic Pollutants Exposure on Human Health by Proteomic Analysis: A Systematic Review

Persistent organic pollutants (POPs) are organic chemical substances that are widely distributed in environments around the globe. POPs accumulate in living organisms and are found at high concentrations in the food chain. Humans are thus continuously exposed to these chemical substances, in which they exert hepatic, reproductive, developmental, behavioral, neurologic, endocrine, cardiovascular, and immunologic adverse health effects. However, considerable information is unknown regarding the mechanism by which POPs exert their adverse effects in humans, as well as the molecular and cellular responses involved. Data are notably lacking concerning the consequences of acute and chronic POP exposure on changes in gene expression, protein profile, and metabolic pathways. We conducted a systematic review to provide a synthesis of knowledge of POPs arising from proteomics-based research. The data source used for this review was PubMed. This study was carried out following the PRISMA guidelines. Of the 742 items originally identified, 89 were considered in the review. This review presents a comprehensive overview of the most recent research and available solutions to explore proteomics datasets to identify new features relevant to human health. Future perspectives in proteomics studies are discussed.

Hepatoprotective Effect of Grape Seed and Skin Extract Against Lithium Exposure Examined by the Window of Proteomics

Context

The liver is the organ by which the majority of substances are metabolized, including psychotropic drugs. Lithium (Li) used as drug for many neurological disorders such as bipolar disorders.

Objective

This study aims to assess lithium toxicity and to evaluate the hepatic-protective properties of a grape skin seed and extract (GSSE).

Materials and methods

Twenty-four male Wistar rats were exposed for 30 days to either various lithium concentrations, GSSE alone, or lithium supplemented with GSSE. The proteomic analysis revealed alterations of liver protein profiles after lithium treatments that were successfully identified by mass spectrometry.

Results

Lithium treatment induced an oxidative damage by the alteration of antioxidant enzymes activities such as superoxide dismutase, CAT, and Gpx. The regulated proteins are mainly involved in the respiratory electron transport chain, detoxification processes, ribosomal stress pathway, glycolysis, and cytoskeleton. Proteins were differentially expressed in a dose-dependent manner. Interestingly, GSSE reversed the situation and restored the level of liver proteins whose abundance was modified after lithium treatment, arguing for its protective activity.

Conclusion

Our data demonstrated the ability of proteomic analysis to underline the toxicity mechanisms of lithium in animal models. Based on these results, GSSE may be envisaged as a nutritional supplement to weaken the liver toxicity of lithium.

Head-to-Head Study of Developmental Neurotoxicity and Resultant Phenotype in Rats: α-Hexabromocyclododecane versus Valproic Acid, a Recognized Model of Reference for Autism Spectrum Disorders

Evidence is now growing that exposure to environmental pollutants during the critical early-life period of brain development may contribute to the emergence of Autism Spectrum Disorders (ASD). This study seeks to compare the developmental neurotoxicity of the α-isomer of hexabromocyclododecane (α-HBCDD), a persistent brominated flame retardant, to the valproic acid (VPA) model of ASD in rodents. Pregnant Wistar rats were divided into three groups: control, α-HBCDD (100 ng/kg/day p.o., GD0-PND21) and VPA (600 mg/kg i.p., GD12). Male offspring were tested for their neuromotor development from PND2-21. At PND21, brain functionality was assessed by measuring cytochrome oxidase activity (CO). Modifications in neuroglia and synaptic plasticity were evaluated in the cortex. Similar subtle behavioural changes related to neuromotor maturation and noise reaction were observed in both treated groups. At PND21, a reduction in CO activity was measured in the VPA group only, in specific areas including auditory nuclei, visual cortex, cingulate and frontal cortices. At the same age, α-HBCDD pointed out significant overexpression of cortical markers of synaptic plasticity while both treated groups showed a significant under expression of astrocyte proteins (S100-β and GFAP). Early-life exposure to a low dose of α-HBCDD may trigger neurobehavioural alterations in line with ASD.

Update of the risk assessment of hexabromocyclododecanes (HBCDDs) in food

The European Commission asked EFSA to update its 2011 risk assessment on hexabromocyclododecanes (HBCDDs) in food. HBCDDs, predominantly mixtures of the stereoisomers α-, β- and γ-HBCDD, were widely used additive flame retardants. Concern has been raised because of the occurrence of HBCDDs in the environment, food and in humans. Main targets for toxicity are neurodevelopment, the liver, thyroid hormone homeostasis and the reproductive and immune systems. The CONTAM Panel concluded that the neurodevelopmental effects on behaviour in mice can be considered the critical effects. Based on effects on spontaneous behaviour in mice, the Panel identified a lowest observed adverse effect level (LOAEL) of 0.9 mg/kg body weight (bw) as the Reference Point, corresponding to a body burden of 0.75 mg/kg bw. The chronic intake that would lead to the same body burden in humans was calculated to be 2.35 μg/kg bw per day. The derivation of a health-based guidance value (HBGV) was not considered appropriate. Instead, the margin of exposure (MOE) approach was applied to assess possible health concerns. Over 6,000 analytical results for HBCDDs in food were used to estimate the exposure across dietary surveys and age groups of the European population. The most important contributors to the chronic dietary LB exposure to HBCDDs were fish meat, eggs, livestock meat and poultry. The CONTAM Panel concluded that the resulting MOE values support the conclusion that current dietary exposure to HBCDDs across European countries does not raise a health concern. An exception is breastfed infants with high milk consumption, for which the lowest MOE values may raise a health concern.

Sorption Behavior of Hexabromocyclododecanes (HBCDs) on Weihe River Sediment

The sorption of hexabromocyclododecanes (HBCDs) on sediment affects the fate and transport of HBCDs in rivers. The sorption of HBCDs on sediment from the Weihe River was investigated by performing batch equilibration experiments, and the effects of changing the pH ionic, strength, and humic acid concentration (HA) on sorption were evaluated. The obtained results indicated that fast rather than slow sorption was the dominant process. Nonlinear sorption isotherms were acquired, and the Freundlich (R² 0.94–0.98) and Langmuir (R² 0.95–0.99) models both described the sorption of HBCDs well. The adsorption capacity for α-HBCD, β-HBCD, and γ-HBCD were calculated using the Langmuir model, and were 443.56, 614.29 and 1146.37 mg/kg, respectively. Thermodynamic analysis shows that HBCDs sorption on sediment is a spontaneous exothermic process. HBCDs sorption was affected by the HA concentration and ionic strength. The amounts of HBCDs sorbed to the sediment decreased as the ionic strength increased, and first increased and then decreased as the HA concentration increased. Changes in pH did not clearly affect the sorption of HBCDs. Synchrotron radiation Fourier-transform infrared spectra (SR-FTIR) was used to characterize the adsorption mechanism, and the obtained result indicated that hydrophobic interactions dominated the mechanism involved in HBCDs sorption on sediment.

The enrichment and purification of hexabromocyclododecanes and its effects on thyroid in zebrafish

Hexabromocyclododecanes (HBCDs) are the third most highly produced brominated flame retardants (BFRs) all over the world. Based on the current research status of HBCDs, zebrafish were exposed to three dietary concentrations of HBCDs (0, 10, 100, 400 ng/g) for 56 days, and followed by clean food for 28 days. In order to investigate the enrichment and purification of HBCDs in zebrafish, HBCD enantiomers in zebrafish were determined using ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). To investigate the effects of long-term exposure of HBCDs on thyroid dysfunction and oxidative stress in zebrafish, the concentrations of thyroid hormone (T3, T4, FT3 and FT4) and the activities of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH) were measured. RT-PCR was used to reveal the molecular mechanism of HBCDs' influence on thyroid hormone in zebrafish. The result of UPLC-MS/MS showed that there were three main reasons for the existence of α-HBCD as the major isomer in the organism. HBCDs had significant inhibitory effect on T3 and T4 in liver of adult zebrafish after 56 days' exposure. Compared with the control group, the ratio of T3 and T4was significantly higher in the medium and high concentration group. The content of FT3 and FT4 in the liver tissue of zebrafish increased first and then decreased with the increase of exposure concentration. With the increase of exposure concentration, the content of MDA in zebrafish liver decreased firstly and then increased. The activity of SOD and CAT in zebrafish liver showed the opposite trend with MDA. And the concentration of GSH in liver decreased gradually, which showed a significant dose-effect relationship. HBCDs exposure has an inhibitory effect on thyroid hormone receptor gene (TRβ) and adrenocorticotropin-releasing hormone gene (Crh) in zebrafish.

Dietary exposure and risk assessment of exposure to hexabromocyclododecanes in a Taiwan population

Hexabromocyclododecane (HBCD) is commonly used in commercial products and factories. HBCDs can be detected in the air, bioaccumulated deposits, water, soil, sediments, and in biota and foodstuffs in the food-chain because they are not chemically bound to the polymer. We determined the levels of α-, β-, and γ-HBCDs in 270 foodstuffs and the doses of HBCDs Taiwanese are normally exposed to. We also wanted to create a strategy of risk management for HBCDs based on margins of exposure (MOE). HBCDs were frequently detectible in fish, seafood, and poultry. Their highest concentrations were in fish, oil, poultry, and livestock. The highest estimated daily intake was in 0- to 3-year-olds (1.576 ng/kg/day), and lower in 3- to 6- (1.064 ng/kg/day), 6- to 12- (0.899 ng/kg/day), and lowest in 12- to 16- (0.632 ng/kg/day) year-olds. The exposure doses to HBCDs indicated no health concern for Taiwanese. Except for fish, significant concentrations of α- and γ-HBCDs were detected in many other foodstuffs, which might indicate that exposure to HBCD is a relatively recent problem. Therefore, one goal of a management policy should be to follow-up the flow direction of HBCDs in Taiwan.

Hepatic transcriptional dose-response analysis of male and female Fischer rats exposed to hexabromocyclododecane

Hexabromocyclododecane (HBCD) is a brominated flame retardant found in the environment and human tissues. The toxicological effects of HBCD exposure are not clearly understood. We employed whole-genome RNA-sequencing on liver samples from male and female Fischer rats exposed to 0, 250, 1250, and 5000 mg technical mixture of HBCD/kg diet for 28 days to gain further insight into HBCD toxicity. HBCD altered 428 and 250 gene transcripts in males and females, respectively, which were involved in metabolism of xenobiotics, oxidative stress, immune response, metabolism of glucose and lipids, circadian regulation, cell cycle, fibrotic activity, and hormonal balance. Signature analysis supported that HBCD operates through the constitutive androstane and pregnane X receptors. The median transcriptomic benchmark dose (BMD) for the lowest statistically significant pathway was within 1.5-fold of the BMD for increased liver weight, while the BMD for the lowest pathway with at least three modeled genes (minimum 5% of pathway) was similar to the lowest apical endpoint BMD. The results show how transcriptional analyses can inform mechanisms underlying chemical toxicity and the doses at which potentially adverse effects occur. This experiment is part of a larger study exploring the use of toxicogenomics and high-throughput screening for human health risk assessment.

Biomagnification of Hexabromocyclododecane (HBCD) in a coastal ecosystem near a large producer in China: Human exposure implication through food web transfer

Hexabromocyclododecane (HBCD) is a widely used brominated flame retardant which is mainly produced in China. Many HBCD facilities are located at the coast and the released HBCD may enter into the coastal ecosystem. There is a risk that HBCD can transfer through the food web to the diet of local population. Therefore, the coastal organisms near one of the biggest HBCD facilities in China were investigated. Variation was observed for the bioaccumulation of HBCD between the detrital food chain and the grazing food chain. In the studied species, the mullet was most contaminated which may be caused by its feeding on detritus. At the same time, the transfer of HBCD along the food web was investigated, and HBCD was biomagnified from the prey to the predator in the grazing food chains. Among the three diastereoisomers, α-HBCD was biomagnified with increasing trophic levels in the food web while β- and γ-HBCD were not. To assess the human dietary exposure, the dietary intake of HBCD from seafood was estimated, and the estimated daily intake (EDI) was 5.22ng/kg/day for adults, and 16.39ng/kg/day for children. The EDI for local residents were tens of times higher than that for general population in China, but the risk through dietary intake was very low in terms of existing reference dose.

Antioxidant gene expression and metabolic responses of earthworms (Eisenia fetida) after exposure to various concentrations of hexabromocyclododecane

Hexabromocyclododecane (HBCD), a ubiquitous suspected contaminant, is one of the world's most prominent brominated flame retardants (BFRs). In the present study, earthworms (Eisenia fetida) were exposed to HBCD. The expression of selected antioxidant enzyme genes was measured, and the metabolic responses were assessed using nuclear magnetic resonance (NMR) to identify the molecular mechanism of the antioxidant stress reaction and the metabolic reactions of earthworms to HBCD. A significant up-regulation (p < 0.05) of superoxide dismutase (SOD) gene expression was detected, with the highest gene expression level of SOD appearing at a dose of 400 mg kg^-1 dw (2.06-fold, p < 0.01). However, the glutathione transferase (GST) gene expression levels did not differ significantly (p > 0.05). Principal component analysis (PCA) of the metabolic responses showed that all groups could be clearly differentiated, and the highest concentration dose group was the most distant from the control group. Except for fumarate, the measured metabolites, which included adenosine triphosphate (ATP), valine, lysine, glycine, betaine and lactate, revealed significant (p < 0.05) increases after 14 days of exposure to HBCD. HBCD likely induces high levels of anaerobic respiration, which would result in high levels of ATP and lead to the disintegration of proteins into amino acids, including valine and lysine, to produce energy. The observed changes in osmotic pressure were indicative of damage to the membrane structure. Furthermore, this study showed that NMR-based metabolomics was a more sensitive tool than measuring the gene expression levels for elucidating the mode of toxicity of HBCD in earthworm exposure studies.

Parallel in vivo and in vitro transcriptomics analysis reveals calcium and zinc signalling in the brain as sensitive targets of HBCD neurotoxicity

Hexabromocyclododecane (HBCD) is a brominated flame retardant (BFR) that accumulates in humans and affects the nervous system. To elucidate the mechanisms of HBCD neurotoxicity, we used transcriptomic profiling in brains of female mice exposed through their diet to HBCD (199 mg/kg body weight per day) for 28 days and compared with those of neuronal N2A and NSC-19 cell lines exposed to 1 or 2 µM HBCD. Similar pathways and functions were affected both in vivo and in vitro, including Ca²⁺ and Zn²⁺ signalling, glutamatergic neuron activity, apoptosis, and oxidative stress. Release of cytosolic free Zn²⁺ by HBCD was confirmed in N2A cells. This Zn²⁺ release was partially quenched by the antioxidant N-acetyl cysteine indicating that, in accordance with transcriptomic analysis, free radical formation is involved in HBCD toxicity. To investigate the effects of HBCD in excitable cells, we isolated mouse hippocampal neurons and monitored Ca²⁺ signalling triggered by extracellular glutamate or zinc, which are co-released pre-synaptically to trigger postsynaptic signalling. In control cells application of zinc or glutamate triggered a rapid rise of intracellular [Ca²⁺]. Treatment of the cultures with 1 µM of HBCD was sufficient to reduce the glutamate-dependent Ca²⁺ signal by 50%. The effect of HBCD on zinc-dependent Ca²⁺ signalling was even more pronounced, resulting in the reduction of the Ca²⁺ signal with 86% inhibition at 1 µM HBCD. Our results show that low concentrations of HBCD affect neural signalling in mouse brain acting through dysregulation of Ca²⁺ and Zn²⁺ homeostasis.

Hexabromocyclododecane and tetrabromobisphenol A in tree bark from different functional areas of Shanghai, China: levels and spatial distributions

The concentrations and spatial distributions of hexabromocyclododecane (HBCDD) and tetrabromobisphenol A (TBBPA) were measured in tree bark from different functional areas of Shanghai. ΣHBCDD (sum of α-, β-, and γ-HBCDD) concentrations ranged from 1.2 × 10² to 6.6 × 10³ ng g^-1 lw (median 5.7 × 10² ng g^-1 lw) and TBBPA concentrations ranged from 48 to 7.2 × 10⁴ ng g^-1 lw (median 2.8 × 10² ng g^-1 lw). The concentrations of ΣHBCDD and TBBPA all followed the order of industrial areas > commercial areas > residential areas. The mean percentage of α-HBCDD in bark samples (44%) from Shanghai was higher than that in technical HBCDD products, but comparable with that in air. The concentrations of TBBPA and individual HBCDD diastereoisomers between industrial areas and commercial areas were correlated. Based on the concentrations of HBCDD in the bark, the corresponding atmospheric HBCDD concentrations were estimated. Compared with the published data for HBCDD in urban air, the estimated atmospheric HBCDD concentrations in Shanghai had a relatively high level, and more attention should be paid to the pollution status of HBCDD in Shanghai.

Gender specific differences in the liver proteome of rats exposed to short term and low-concentration hexabromocyclododecane (HBCD)

The influence of short term (7-day) exposure of male rats to the brominated flame retardant hexabromocyclododecane (HBCD) was studied by investigation of the liver proteome, both in euthyroid and hypothyroid rats and by comparing results with general data on animal physiology and thyroid hormone, leptin, insulin and gonadotropin concentrations determined in parallel. Proteome analysis of liver tissue by two-dimensional fluorescence difference gel electrophoresis (2D-DIGE) revealed that only small protein pattern changes were induced by exposure in males, on just a few proteins with different functions and not involved in pathways in common. This is in contrast to previous findings in similarly exposed eu- and hypothyroid female rats, where general metabolic pathways had been shown to be affected. The largest gender-dependent effects concerned basal concentrations of liver proteins already in control and hypothyroid animals, involving mainly the pathways which were also differently affected by HBCD exposure. Among them were differences in lipid metabolism, which - upon exposure to HBCD - may also be the reason for the considerably higher ratio of γ-HBCD accumulated in white adipose tissue of exposed female rats compared to males. The results further elucidate the already suggested different sensitivity of genders towards HBCD exposure on the protein level, and confirm the need for undertaking toxicological animal experiments in both genders.

Dataset of liver proteins of eu- and hypothyroid rats affected in abundance by any of three factors: in vivo exposure to hexabromocyclododecane (HBCD), thyroid status, gender differences

Male Wistar rats with different thyroid status (eu-, hypothyroid) were exposed to 0, 3 or 30 mg/kg body weight of the flame retardant HBCD for 7 days and obtained data compared with a previous study in females, “Hexabromocyclododecane (HBCD) induced changes in the liver proteome of eu- and hypothyroid female rats” (Miller et al., 2016) [1]. Specifically, proteomic investigation of liver protein patterns obtained by 2D-DIGE was performed and differences between animals groups recorded, based on the factors exposure, thyroid status and gender. All proteins with significantly changed abundance in any of these comparisons were identified by mass spectrometry. General, hormone and proteomic data of both the present and the previous studies are discussed in Miller et al. (2016) [1] and in "Gender specific differences in the liver proteome of rats exposed to hexabromocyclododecane (HBCD)" Miller et al. (2016) [2].

Dataset of liver proteins changed in eu- and hypothyroid female rats upon in vivo exposure to hexabromocyclododecane (HBCD)

Female Wistar rats with different thyroid status (eu-, hypothyroid) were exposed to 0, 3 or 30 mg/kg body weight of the flame retardant HBCD for 7 days. Changes in protein patterns obtained by 2D-DIGE were evaluated, and different animal groups compared taking into account their exposure and thyroid status. Proteins significantly altered in abundance in any of these comparisons were identified by mass spectrometry. These data, together with hormone data of the animals, are discussed in “Hexa-bromocyclododecane (HBCD) induced changes in the liver proteome of eu- and hypothyroid female rats” (Miller et al., 2016) [1].