Sex differences in liver toxicity-do female and male human primary hepatocytes react differently to toxicants in vitro?

Morin hydrate ameliorates Di-2-ethylhexyl phthalate (DEHP) induced hepatotoxicity in a mouse model via TNF-α and NF-κβ signaling

Di-(2-ethylhexyl) phthalic acid (DEHP) pollutes the environment, and posing a significant risk to human and animal health. Consequently, a successful preventative strategy against DEHP-induced liver toxicity needs to be investigated. Morin hydrate (MH), a flavanol compound, possesses toxic preventive attributes against various environmental pollutants. However, the effects of MH have not been investigated against DEHP-induced liver toxicity. Female Swiss albino mice were divided into four groups: control, DEHP (orally administered with 500 mg/kg, DEHP plus MH 10 mg/kg, and DEHP plus MH 100 mg/kg for 14 days. The results showed that the MH treatment ameliorated the DEHP-induced liver dysfunctions by decreasing the alanine transaminase (ALT), aspartate aminotransferase (AST), total bilirubin, liver histoarchitecture, fibrosis, and markers of oxidative stress. Furthermore, DEHP increased apoptosis, increased active caspase 3 and decreased B cell lymphoma-2 (Bcl-2) expression. However, the MH treatment showed a differential effect on these proteins; a lower dose increased, and a higher dose decreased the expression. Thus, a lower dose of MH could be involved in the disposal of damaged hepatocytes. Expression of Estrogen receptors alpha (ERα) also showed a similar trend with active caspase 3. Furthermore, the expression of Tumor necrosis factor alpha (TNF-α) and Nuclear factor-κβ (NF-κβ) were up-regulated by DEHP treatment, and MH treatment down-regulated the expression of these two inflammatory markers. Since this down-regulation of TNF-α and NF-κβ coincides with improved liver functions against DEHP-induced toxicity, it can be concluded that MH-mediated liver function involves the singling of TNF-α and NF-κβ.

Control compounds for preclinical drug-induced liver injury assessment: Consensus-driven systematic review by the ProEuroDILI network

BACKGROUND & AIMS

Idiosyncratic drug-induced liver injury (DILI) is a complex and unpredictable event caused by drugs, and herbal or dietary supplements. Early identification of human hepatotoxicity at preclinical stages remains a major challenge, in which the selection of validated in vitro systems and test drugs has a significant impact. In this systematic review, we analyzed the compounds used in hepatotoxicity assays and established a list of DILI-positive and -negative control drugs for validation of in vitro models of DILI, supported by literature and clinical evidence and endorsed by an expert committee from the COST Action ProEuroDILI Network (CA17112).

METHODS

Following 2020 PRISMA guidelines, original research articles focusing on DILI which used in vitro human models and performed at least one hepatotoxicity assay with positive and negative control compounds, were included. Bias of the studies was assessed by a modified 'Toxicological Data Reliability Assessment Tool'.

RESULTS

A total of 51 studies (out of 2,936) met the inclusion criteria, with 30 categorized as reliable without restrictions. Although there was a broad consensus on positive compounds, the selection of negative compounds lacked clarity. 2D monoculture, short exposure times and cytotoxicity endpoints were the most tested, although there was no consensus on drug concentrations.

CONCLUSIONS

Extensive analysis highlighted the lack of agreement on control compounds for in vitro DILI assessment. Following comprehensive in vitro and clinical data analysis together with input from the expert committee, an evidence-based consensus-driven list of 10 positive and negative control drugs for validation of in vitro models of DILI is proposed.

IMPACT AND IMPLICATIONS

Prediction of human toxicity early in the drug development process remains a major challenge, necessitating the development of more physiologically relevant liver models and careful selection of drug-induced liver injury (DILI)-positive and -negative control drugs to better predict the risk of DILI associated with new drug candidates. Thus, this systematic study has crucial implications for standardizing the validation of new in vitro models of DILI. By establishing a consensus-driven list of positive and negative control drugs, the study provides a scientifically justified framework for enhancing the consistency of preclinical testing, thereby addressing a significant challenge in early hepatotoxicity identification. Practically, these findings can guide researchers in evaluating safety profiles of new drugs, refining in vitro models, and informing regulatory agencies on potential improvements to regulatory guidelines, ensuring a more systematic and efficient approach to drug safety assessment.

Oral exposure to food grade titanium dioxide (E171) induces intestinal and behavioural alterations in adult mice but limited effects in young mice

BACKGROUND

Food-grade titanium dioxide (E171), a white colourant widely used in ultra-processed food products, has been banned in the European Union. However, its usage is still permitted in medicines, and in several other countries. The estimated intake of E171 in children is higher than in adults, which led us to hypothesise that E171 induces differential effects depending on age, with adult mice being the most susceptible due to age, despite the lower dose.

AIM

To evaluate the effects of oral administration of E171 on intestinal permeability, ileum, and colon histology, and how these effects impact anxious and depressive behaviour in young and adult mice of both sexes.

METHODS

Young and adult mice of both sexes C57BL/6 mice received 10 mg/kgbw E171/3 times per week for 3 months. E171 was administered orally in water by pipetting, while control groups only received drinking water, then intestinal permeability, histology and animal behaviour were analysed.

RESULTS

E171 showed an amorphous shape, primary particles sized below 1 µm and anatase crystalline structure. Oral administration of E171 disrupted the intestinal permeability in adult male and female mice, but no effects were observed in young mice of both sexes. E171 promoted ileal adenoma formation in half of the adult female population, moreover hyperplastic crypts, and hyperplastic goblet cells at histological level in adult mice of both sexes. The colon presented hyperplastic goblet cells, hyperchromatic nuclei, increased proliferation and DNA damage in adult mice of both sexes. The anxiety and depressive behaviour were only altered in adult mice treated with E171, but no changes were detected in young animals of both sexes.

CONCLUSIONS

Adult mice displayed higher susceptibility in all parameters analysed in this study compared to young mice of both sexes.

Effects of acute insecticide exposure on neuronal activity in vitro in rat cortical cultures

Exposure to pesticides, such as carbamates, organophosphates, organochlorines and pyrethroids, has been linked to various health problems, including neurotoxicity. Although most in vivo studies use only male rodents, some studies have shown in vivo sex-specific effects after acute exposure. Since in vivo studies are costly and require a large number of animals, in vitro assays that take sex-specific effects into account are urgently needed. We therefore assessed the acute effects of exposure to different carbamates (methomyl, aldicarb and carbaryl), organophosphates (chlorpyrifos (CPF), chlorpyrifos-oxon (CPO) and 3,5,6-trichloropyridinol), organochlorines (endosulfan, dieldrin and lindane) and pyrethroids (permethrin, alpha-cypermethrin and 3-phenoxy-benzoic acid (3-PBA)) on neuronal network function in sex-separated rat primary cortical cultures using micro-electrode array (MEA) recordings. Our results indicate that exposure to the carbamate carbaryl and the organophosphates CPF and CPO decreased neuronal activity, with CPO being the most potent. Notably, (network) burst patterns differed between CPF and CPO, with CPO inducing fewer, but more intense (network) bursts. Exposure to low micromolar levels of endosulfan induced a hyperexcitation, most likely due to the antagonistic effects on GABA receptors. Interestingly, females were more sensitive to endosulfan than males. Exposure to dieldrin and lindane also increased neuronal activity, albeit less than endosulfan and without sex-specific effects. Exposure to type I pyrethroid permethrin increased neuronal activity, while exposure to type II pyrethroid alpha-cypermethrin strongly decreased neuronal activity. The increase seen after permethrin exposure was more pronounced in males than in females. Together, these results show that acute exposure to different classes of pesticides exerts differential effects on neuronal activity. Moreover, it shows that MEA recordings are suited to detect sex-specific neurotoxic effects in vitro.

Protective effect of alpha‑lipoic acid against in utero cytarabine exposure-induced hepatotoxicity in rat female neonates

Cytarabine, an anti-metabolite drug, remains the mainstay of treatment for hematological malignancies. It causes various toxic effects including teratogenicity. Alpha lipoic acid (ALA) is a natural antioxidant reported to offer protection against hepatotoxicity induced by various pathological conditions, drugs, or chemicals. We investigated the protective effect of ALA against prenatal cytarabine exposure-induced hepatotoxicity in rat female neonates. A total of 30 dams were randomly assigned to five groups and received normal saline, ALA 200 mg/kg, cytarabine 12.5 mg/kg, cytarabine 25 mg/kg, and cytarabine 25 mg/kg + ALA 200 mg/kg, respectively, from gestational day (GD)8 to GD21. Cytarabine and ALA were administered via intraperitoneal and oral (gavage) routes, respectively. On postnatal day (PND)1, all the live female neonates (pups) were collected and weighed. The blood and liver from pups were carefully collected and used for histopathological, and biochemical evaluations. A significant and dose-dependent decrease in maternal food intake and weight gain was observed in the pregnant rats (dams) of the cytarabine groups as compared to the dams of the control group. The pups exposed to cytarabine showed a significant and dose-dependent (a) decrease in body weight, liver weight, hepatosomatic index, catalase, superoxide dismutase, glutathione, glutathione peroxidase, serum albumin levels and (b) increase in malondialdehyde, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, AST/ALT ratio, and histopathological anomalies. Maternal co-administration of ALA ameliorated these biochemical changes and histopathological abnormalities by combating oxidative stress. Future studies are warranted to explore the molecular mechanisms involved in the ALA's protective effects against prenatal cytarabine-induced hepatotoxicity.

Exploring sex differences: insights into gene expression, neuroanatomy, neurochemistry, cognition, and pathology

Increased knowledge about sex differences is important for development of individualized treatments against many diseases as well as understanding behavioral and pathological differences. This review summarizes sex chromosome effects on gene expression, epigenetics, and hormones in relation to the brain. We explore neuroanatomy, neurochemistry, cognition, and brain pathology aiming to explain the current state of the art. While some domains exhibit strong differences, others reveal subtle differences whose overall significance warrants clarification. We hope that the current review increases awareness and serves as a basis for the planning of future studies that consider both sexes equally regarding similarities and differences.

Sex difference in liver diseases: How preclinical models help to dissect the sex-related mechanisms sustaining NAFLD and hepatocellular carcinoma

Only a few preclinical findings are confirmed in the clinic, posing a critical issue for clinical development. Therefore, identifying the best preclinical models can help to dissect molecular and mechanistic insights into liver disease pathogenesis while being clinically relevant. In this context, the sex relevance of most preclinical models has been only partially considered. This is particularly significant in NAFLD and HCC, which have a higher prevalence in men when compared to pre-menopause women but not to those in post-menopausal status, suggesting a role for sex hormones in the pathogenesis of the diseases. This review gathers the sex-relevant findings and the available preclinical models focusing on both in vitro and in vivo studies and discusses the potential implications and perspectives of introducing the sex effect in the selection of the best preclinical model. This is a critical aspect that would help to tailor personalized therapies based on sex.

Identifying Safety Subgroups at Risk: Assessing the Agreement Between Statistical Alerting and Patient Subgroup Risk

INTRODUCTION

Identifying individual characteristics or underlying conditions linked to adverse drug reactions (ADRs) can help optimise the benefit-risk ratio for individuals. A systematic evaluation of statistical methods to identify subgroups potentially at risk using spontaneous ADR report datasets is lacking.

OBJECTIVES

In this study, we aimed to assess concordance between subgroup disproportionality scores and European Medicines Agency Pharmacovigilance Risk Assessment Committee (PRAC) discussions of potential subgroup risk.

METHODS

The subgroup disproportionality method described by Sandberg et al., and variants, were applied to statistically screen for subgroups at potential increased risk of ADRs, using data from the US FDA Adverse Event Reporting System (FAERS) cumulative from 2004 to quarter 2 2021. The reference set used to assess concordance was manually extracted from PRAC minutes from 2015 to 2019. Mentions of subgroups presenting potential differentiated risk and overlapping with the Sandberg method were included.

RESULTS

Twenty-seven PRAC subgroup examples representing 1719 subgroup drug-event combinations (DECs) in FAERS were included. Using the Sandberg methodology, 2 of the 27 could be detected (one for age and one for sex). No subgroup examples for pregnancy and underlying condition were detected. With a methodological variant, 14 of 27 examples could be detected.

CONCLUSIONS

We observed low concordance between subgroup disproportionality scores and PRAC discussions of potential subgroup risk. Subgroup analyses performed better for age and sex, while for covariates not well-captured in FAERS, such as underlying condition and pregnancy, additional data sources should be considered.

Growth Hormone Accelerates Recovery From Acetaminophen-Induced Murine Liver Injury

Background and Aims

Acetaminophen (APAP) overdose is the leading cause of acute liver failure, with one available treatment, N-acetyl cysteine (NAC). Yet, NAC effectiveness diminishes about ten hours after APAP overdose, urging for therapeutic alternatives. This study addresses this need by deciphering a mechanism of sexual dimorphism in APAP-induced liver injury, and leveraging it to accelerate liver recovery via growth hormone (GH) treatment. GH secretory patterns, pulsatile in males and near-continuous in females, determine the sex bias in many liver metabolic functions. Here, we aim to establish GH as a novel therapy to treat APAP hepatotoxicity.

Approach and Results

Our results demonstrate sex-dependent APAP toxicity, with females showing reduced liver cell death and faster recovery than males. Single-cell RNA sequencing analyses reveal that female hepatocytes have significantly greater levels of GH receptor expression and GH pathway activation compared to males. In harnessing this female-specific advantage, we demonstrate that a single injection of recombinant human GH protein accelerates liver recovery, promotes survival in males following sub-lethal dose of APAP, and is superior to standard-of-care NAC. Alternatively, slow-release delivery of human GH via the safe nonintegrative lipid nanoparticle-encapsulated nucleoside-modified mRNA (mRNA-LNP), a technology validated by widely used COVID-19 vaccines, rescues males from APAP-induced death that otherwise occurred in control mRNA-LNP-treated mice.

Conclusions

Our study demonstrates a sexually dimorphic liver repair advantage in females following APAP overdose, leveraged by establishing GH as an alternative treatment, delivered either as recombinant protein or mRNA-LNP, to potentially prevent liver failure and liver transplant in APAP-overdosed patients.

Statistical methods for exploring spontaneous adverse event reporting databases for drug-host factor interactions

BACKGROUND

Drug toxicity does not affect patients equally; the toxicity may only exert in patients who possess certain attributes of susceptibility to specific drug properties (i.e., drug-host interaction). This concept is crucial for personalized drug safety but remains under-studied, primarily due to methodological challenges and limited data availability. By monitoring a large volume of adverse event reports in the postmarket stage, spontaneous adverse event reporting systems provide an unparalleled resource of information for adverse events and could be utilized to explore risk disparities of specific adverse events by age, sex, and other host factors. However, well-formulated statistical methods to formally address such risk disparities are currently lacking.

METHODS

In this paper, we present a statistical framework to explore spontaneous adverse event reporting databases for drug-host interactions and detect risk disparities in adverse drug events by various host factors, adapting methods for safety signal detection. We proposed four different methods, including likelihood ratio test, normal approximation test, and two tests using subgroup ratios. We applied our proposed methods to simulated data and Food and Drug Administration (FDA) Adverse Event Reporting Systems (FAERS) and explored sex-/age-disparities in reported liver events associated with specific drug classes.

RESULTS

The simulation result demonstrates that two tests (likelihood ratio, normal approximation) can detect disparities in adverse drug events associated with host factors while controlling the family wise error rate. Application to real data on drug liver toxicity shows that the proposed method can be used to detect drugs with unusually high level of disparity regarding a host factor (sex or age) for liver toxicity or to determine whether an adverse event demonstrates a significant unbalance regarding the host factor relative to other events for the drug.

CONCLUSION

Though spontaneous adverse event reporting databases require careful data processing and inference, the sheer size of the databases with diverse data from different countries provides unique resources for exploring various questions for drug safety that are otherwise impossible to address. Our proposed methods can be used to facilitate future investigation on drug-host interactions in drug toxicity using a large number of reported adverse events.

Associations between residential volatile organic compound exposures and liver injury markers: The role of biological sex and race

While occupational exposures to volatile organic compounds (VOCs) have been linked to steatohepatitis and liver cancer in industrial workers, recent findings have also positively correlated low-dose, residential VOC exposures with liver injury markers. VOC sources are numerous; factors including biological make up (sex), socio-cultural constructs (gender, race) and lifestyle (smoking) can influence both VOC exposure levels and disease outcomes. Therefore, the current study's objective is to investigate how sex and race influence associations between residential VOC exposures and liver injury markers particularly in smokers vs. nonsmokers. Subjects (n = 663) were recruited from residential neighborhoods; informed consent was obtained. Exposure biomarkers included 16 urinary VOC metabolites. Serological disease biomarkers included liver enzymes, direct bilirubin, and hepatocyte death markers (cytokeratin K18). Pearson correlations and generalized linear models were conducted. Models were adjusted for common liver-related confounders and interaction terms. The study population constituted approximately 60% females (n = 401) and 40% males (n = 262), and a higher percent of males were smokers and/or frequent drinkers. Both sexes had a higher percent of White (75% females, 82% males) vs. Black individuals. Positive associations were identified for metabolites of acrolein, acrylamide, acrylonitrile, butadiene, crotonaldehyde, and styrene with alkaline phosphatase (ALP), a biomarker for cholestatic injury; and for the benzene metabolite with bilirubin; only in females. These associations were retained in female smokers. Similar associations were also observed between these metabolites and ALP only in White individuals (n = 514). In Black individuals (n = 114), the styrene metabolite was positively associated with aspartate transaminase. Interaction models indicated that positive associations for acrylamide/crotonaldehyde metabolites with ALP in females were dose-dependent. Most VOC associations with K18 markers were negative in this residential population. Overall, the findings demonstrated that biological sex, race, and smoking status influence VOC effects on liver injury and underscored the role of biological-social-lifestyle factor(s) interactions when addressing air pollution-related health disparities.

Exposure to polystyrene nanoplastics induces an anxiolytic-like effect, changes in antipredator defensive response, and DNA damage in Swiss mice

Although the in vivo toxicity of nanoplastics (NPs) has already been reported in different model systems, their effects on mammalian behavior are poorly understood. Thus, we aimed to evaluate whether exposure to polystyrene (PS) NPs (diameter: 23.03 ± 0.266 nm) alters the behavior (locomotor, anxiety-like and antipredator) of male Swiss mice, induces brain antioxidant activity, and erythrocyte DNA damage. For this, the animals were exposed to NPs for 20 days at different doses (6.5 ng/kg and 6500 ng/kg). Initially, we did not observe any effect of pollutants on the locomotor activity of the animals (inferred via open field test and Basso mouse scale for locomotion). However, we noticed an anxiolytic-like behavior (in the open field test) and alterations in the antipredatory defensive response of mice exposed to PS NPs, when confronted with their predator potential (snake, Pantherophis guttatus). Furthermore, such changes were associated with suppressing brain antioxidant activity, inferred by lower DPPH radical scavenging activity, reduced total glutathione content, as well as the translocation and accumulation of NPs in the brain of the animals. In addition, we noted that the treatments induced DNA damage, evaluated via a single-cell gel electrophoresis assay (comet assay) applied to circulating erythrocytes of the animals. However, we did not observe a dose-response effect for all biomarkers evaluated and the estimated accumulation of PS NPs in the brain. The values of the integrated biomarker response index and the results of the principal component analysis (PCA) and the hierarchical clustering analysis confirmed the similarity between the responses of animals exposed to different doses of PS NPs. Therefore, our study sheds light on how PS NPs can impact mammals and reinforce the ecotoxicological risk associated with the dispersion of these pollutants in natural environments and their uptake by mammals.

Drug Metabolism of Hepatocyte-like Organoids and Their Applicability in In Vitro Toxicity Testing

Emerging advances in the field of in vitro toxicity testing attempt to meet the need for reliable human-based safety assessment in drug development. Intrahepatic cholangiocyte organoids (ICOs) are described as a donor-derived in vitro model for disease modelling and regenerative medicine. Here, we explored the potential of hepatocyte-like ICOs (HL-ICOs) in in vitro toxicity testing by exploring the expression and activity of genes involved in drug metabolism, a key determinant in drug-induced toxicity, and the exposure of HL-ICOs to well-known hepatotoxicants. The current state of drug metabolism in HL-ICOs showed levels comparable to those of PHHs and HepaRGs for CYP3A4; however, other enzymes, such as CYP2B6 and CYP2D6, were expressed at lower levels. Additionally, EC50 values were determined in HL-ICOs for acetaminophen (24.0−26.8 mM), diclofenac (475.5−>500 µM), perhexiline (9.7−>31.5 µM), troglitazone (23.1−90.8 µM), and valproic acid (>10 mM). Exposure to the hepatotoxicants showed EC50s in HL-ICOs comparable to those in PHHs and HepaRGs; however, for acetaminophen exposure, HL-ICOs were less sensitive. Further elucidation of enzyme and transporter activity in drug metabolism in HL-ICOs and exposure to a more extensive compound set are needed to accurately define the potential of HL-ICOs in in vitro toxicity testing.

Unveiling Urinary Mutagenicity by the Ames Test for Occupational Risk Assessment: A Systematic Review

Occupational exposure may involve a variety of toxic compounds. A mutagenicity analysis using the Ames test can provide valuable information regarding the toxicity of absorbed xenobiotics. Through a search of relevant databases, this systematic review gathers and critically discusses the published papers (excluding other types of publications) from 2001-2021 that have assessed urinary mutagenicity (Ames test with Salmonella typhimurium) in an occupational exposure context. Due to the heterogeneity of the study methods, a meta-analysis could not be conducted. The characterized occupations were firefighters, traffic policemen, bus drivers, mail carriers, coke oven and charcoal workers, chemical laboratory staff, farmers, pharmacy workers, and professionals from several other industrial sectors. The genetically modified bacterial strains (histidine dependent) TA98, TA100, YG1041, YG1021, YG1024 and YG1042 have been used for the health risk assessment of individual (e.g., polycyclic aromatic hydrocarbons) and mixtures of compounds (e.g., diesel engine exhaust, fire smoke, industrial fumes/dyes) in different contexts. Although comparison of the data between studies is challenging, urinary mutagenicity can be very informative of possible associations between work-related exposure and the respective mutagenic potential. Careful interpretation of results and their direct use for occupational health risk assessment are crucial and yet complex; the use of several strains is highly recommended since individual and/or synergistic effects of complex exposure to xenobiotics can be overlooked. Future studies should improve the methods used to reach a standardized protocol for specific occupational environments to strengthen the applicability of the urinary mutagenicity assay and reduce inter- and intra-individual variability and exposure source confounders.

Harnessing natural variation to identify cis regulators of sex-biased gene expression in a multi-strain mouse liver model

Sex differences in gene expression are widespread in the liver, where many autosomal factors act in tandem with growth hormone signaling to regulate individual variability of sex differences in liver metabolism and disease. Here, we compare hepatic transcriptomic and epigenetic profiles of mouse strains C57BL/6J and CAST/EiJ, representing two subspecies separated by 0.5-1 million years of evolution, to elucidate the actions of genetic factors regulating liver sex differences. We identify 144 protein coding genes and 78 lncRNAs showing strain-conserved sex bias; many have gene ontologies relevant to liver function, are more highly liver-specific and show greater sex bias, and are more proximally regulated than genes whose sex bias is strain-dependent. The strain-conserved genes include key growth hormone-dependent transcriptional regulators of liver sex bias; however, three other transcription factors, Trim24, Tox, and Zfp809, lose their sex-biased expression in CAST/EiJ mouse liver. To elucidate the observed strain specificities in expression, we characterized the strain-dependence of sex-biased chromatin opening and enhancer marks at cis regulatory elements (CREs) within expression quantitative trait loci (eQTL) regulating liver sex-biased genes. Strikingly, 208 of 286 eQTLs with strain-specific, sex-differential effects on expression were associated with a complete gain, loss, or reversal of the sex differences in expression between strains. Moreover, 166 of the 286 eQTLs were linked to the strain-dependent gain or loss of localized sex-biased CREs. Remarkably, a subset of these CREs apparently lacked strain-specific genetic variants yet showed coordinated, strain-dependent sex-biased epigenetic regulation. Thus, we directly link hundreds of strain-specific genetic variants to the high variability in CRE activity and expression of sex-biased genes and uncover underlying genetically-determined epigenetic states controlling liver sex bias in genetically diverse mouse populations.

Sex-Specific Response to Combinations of Shear Stress and Substrate Stiffness by Endothelial Cells In Vitro

By using a full factorial design of experiment, the combinatorial effects of biological sex, shear stress, and substrate stiffness on human umbilical vein endothelial cell (HUVEC) spreading and Yes-associated protein 1 (YAP1) activity are able to be efficiently evaluated. Within the range of shear stress (0.5-1.5 Pa) and substrate stiffness (10-100 kPa), male HUVECs are smaller than female HUVECs. Only with sufficient mechanical stimulation do they spread to a similar size. More importantly, YAP1 nuclear localization in female HUVECs is invariant to mechanical stimulation within the range of tested conditions whereas for male HUVECs it increases nonlinearly with increasing shear stress and substrate stiffness. The sex-specific response of HUVECs to combinations of shear stress and substrate stiffness reinforces the need to include sex as a biological variable and multiple mechanical stimuli in experiments, informs the design of precision biomaterials, and offers insight for understanding cardiovascular disease sexual dimorphisms. Moreover, here it is illustrated that different complex mechanical microenvironments can lead to sex-specific phenotypes and sex invariant phenotypes in cultured endothelial cells.

Sex-Related Differences in Drugs with Anti-Inflammatory Properties

There is increasing evidence of sex differences in the action of anti-inflammatory drugs, with women being at significantly higher risk of adverse effects. Nevertheless, clinicians' awareness of the implications of these sex differences on dosing and adverse event monitoring in routine practice is still in need of improvement. We reviewed the literature evaluating sex differences in terms of pharmacokinetics and pharmacodynamics of anti-inflammatory drugs. The anti-thrombotic activity of selective and non-selective COX-inhibitors tends to be stronger in men than women. Side effect profiles differ with regards to gastro-intestinal, renal and hepatic complications. Glucocorticosteroids were found to be more effective in men; women were more sensitive to corticosteroids when their oestradiol levels were high, a finding important for women taking hormonal contraception. TNF-alpha inhibitors have a longer half-life in men, leading to stronger immunosuppression and this a higher incidence of infections as side effects. Although research on sex differences in the effectiveness and safety of drugs is increasing, findings are often anecdotal and controversial. There is no systematic sex-differentiated reporting from clinical trials, and women are often under-represented. As personalized medicine is gaining in importance, sex, and gender aspects need to become integral parts of future research and policy making.

Large-scale labeling and assessment of sex bias in publicly available expression data

BACKGROUND

Women are at more than 1.5-fold higher risk for clinically relevant adverse drug events. While this higher prevalence is partially due to gender-related effects, biological sex differences likely also impact drug response. Publicly available gene expression databases provide a unique opportunity for examining drug response at a cellular level. However, missingness and heterogeneity of metadata prevent large-scale identification of drug exposure studies and limit assessments of sex bias. To address this, we trained organism-specific models to infer sample sex from gene expression data, and used entity normalization to map metadata cell line and drug mentions to existing ontologies. Using this method, we inferred sex labels for 450,371 human and 245,107 mouse microarray and RNA-seq samples from refine.bio.

RESULTS

Overall, we find slight female bias (52.1%) in human samples and (62.5%) male bias in mouse samples; this corresponds to a majority of mixed sex studies in humans and single sex studies in mice, split between female-only and male-only (25.8% vs. 18.9% in human and 21.6% vs. 31.1% in mouse, respectively). In drug studies, we find limited evidence for sex-sampling bias overall; however, specific categories of drugs, including human cancer and mouse nervous system drugs, are enriched in female-only and male-only studies, respectively. We leverage our expression-based sex labels to further examine the complexity of cell line sex and assess the frequency of metadata sex label misannotations (2-5%).

CONCLUSIONS

Our results demonstrate limited overall sex bias, while highlighting high bias in specific subfields and underscoring the importance of including sex labels to better understand the underlying biology. We make our inferred and normalized labels, along with flags for misannotated samples, publicly available to catalyze the routine use of sex as a study variable in future analyses.

Subchronic oral toxicity evaluation of gold nanoparticles in male and female mice

Gold nanoparticles (AuNPs) are biocompatible nanomaterials with potential application in the food industry. The safety of AuNPs oral consumption remains inconclusive, and information on possible long-term toxicity is limited. The current study aimed to evaluate the subchronic oral toxicity of AuNPs in male and female Institute of Cancer Research (ICR) mice. Citrate-coated spherical AuNPs with 53 nm diameters were prepared and orally administered to the mice. No mortality or clinical abnormalities were observed following daily administration of AuNPs at the dosages of 0.2, 2, and 20 mg/kg for 90 days. There was no significant difference in body weight or the relative organs' weights between the control and AuNPs-treated mice. No gross abnormalities or histopathological changes were observed except that the male mice treated with high dose (20 mg/kg AuNPs) showed minor infiltration in the kidneys, and female mice showed a reduced A/G ratio and elevated platelet indices. Overall, the 90-day long-term oral consumption of AuNPs did not cause significant toxicity in mice.

Hepatoprotective effect of Omega-3 PUFAs against acute paracetamol-induced hepatic injury confirmed by FTIR

Acute paracetamol over dose-induced hepatotoxicity is considered an important medical hazard especially among women. Omega-3 long-chain polyunsaturated fatty acids (Omega-3 PUFAs) daily doses are nowadays recommended for their antioxidant and anti-inflammatory potentials. Fourier transform infrared (FTIR) spectroscopy is considered a reliable method in analyzing cellular alterations and is now efficiently used to diagnose several diseases and the efficacy of drugs even in the early stages. The aim of our study was to evaluate the hepatoprotective effect of Omega-3 PUFAs against paracetamol-induced hepatotoxicity in rats confirmed through measuring protein alterations in hepatocytes by FTIR. Rats were pretreated with Omega-3 PUFAs (50 and 100 mg/kg) for 21 days prior to oral ingestion of paracetamol. FTIR results revealed that Omega-3 PUFAs (50 mg/kg) limited the toxic effects of paracetamol by restoring the hepatic amide I to amide II ratio. In addition; biochemical analyses demonstrated that serum ALT, AST, Cholesterol, LDL-cholesterol and Il-6 levels as well as hepatic TNF-α, MDA, NOx levels were decreased. Besides; serum HDL-cholesterol level and hepatic GSH level were increased. Histopathological examinations of hepatic sections validated the hepatoprotective potential. The overall effect of this dose was comparable to those of the usual recommended hepatoprotective supplement; silymarin. In conclusion; it would be recommended to use Omega-3 PUFAs in low doses on daily bases as a hepatoprotective agent.

High-Content Screening for the Detection of Drug-Induced Oxidative Stress in Liver Cells

Drug-induced liver injury (DILI) remains a major cause of drug development failure, post-marketing warnings and restriction of use. An improved understanding of the mechanisms underlying DILI is required for better drug design and development. Enhanced reactive oxygen species (ROS) levels may cause a wide spectrum of oxidative damage, which has been described as a major mechanism implicated in DILI. Several cell-based assays have been developed as in vitro tools for early safety risk assessments. Among them, high-content screening technology has been used for the identification of modes of action, the determination of the level of injury and the discovery of predictive biomarkers for the safety assessment of compounds. In this paper, we review the value of in vitro high-content screening studies and evaluate how to assess oxidative stress induced by drugs in hepatic cells, demonstrating the detection of pre-lethal mechanisms of DILI as a powerful tool in human toxicology.

Acute and repeated-dose toxicity of Echinops kebericho Mesfin essential oil

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No mortality was observed up to 2000 mg/kg dose in acute toxicity study of Echinops kebericho essential oil.

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On repeated-dose toxicity study, essential oil treated groups and controls did not show significant variations.

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No significant variation was observed in food consumption, body and organ weight, and histopathology between treated and control groups.

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Urea, albumin, aspartate aminotransferase, andorgan weight of kidney significantly varied between some treated groups compared to control.

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Significant variations were observed between male and female in many parameters.

Echinops kebericho Mesfin is used for the management of various diseases and fumigation during child birth. This study investigated acute and repeated-dose toxicity of E. kebericho M. essential oils (EOs). The study was conducted in Swiss albino mice. Organ weight, histopathology and clinical chemistry were analyzed. The dose and duration of treatment were defined in accordance with Organization for Economic Co-operation and Development (OECD) guideline.

No mortality was observed in acute oral dose toxicity study up to 2000 mg/kg per body weight. Compared to control group, treated groups did not show significant abnormalities in body weight and most parameters of clinical chemistry parameters and relative organ weight in repeated-dose toxicity study. However, urea, albumin, aspartate aminotransferase, and relative organ weight of right kidney showed variations in treated groups compared to control group. All treated groups and control group showed normal histology except lymphocytic infiltrates observed on the kidney with 200 mg/kg treated female group. The current study revealed that EO of E. kebericho M. could be considered well tolerated in acute and repeated-dose exposure. Further, teratogenic, mutagenic, carcinogenic, and sub-chronic and chronic toxicity studies are warranted.

Sex-linked differences in the course of thioacetamide-induced acute liver failure in Lewis rats

Acute liver failure (ALF) is a clinical syndrome with high mortality rate, resulting from widespread hepatocyte damage. Its pathophysiological background is still poorly understood and preclinical studies evaluating pathophysiology and new potential therapeutic measures are needed. The model of ALF induced by administration of thioacetamide (TAA) in Lewis rats is recommended as optimal; however, the limitation of previous studies was that they were performed predominantly in male rats. In view of the growing recognition that sex as a biological variable should be taken into consideration in preclinical research, we examined its role in the development of TAA-induced ALF in Lewis rats. We found that, first, intact male Lewis rats showed lower survival rate than their female counterparts, due to augmented liver injury documented by higher plasma ammonia, and bilirubin levels and alanine aminotransferase activity. Second, in female rats castration did not alter the course of TAA-induced ALF whereas in the male gonadectomy improved the survival rate and attenuated liver injury, reducing it to levels observed in their female counterparts. In conclusion, we found that Lewis rats show a remarkable sexual dimorphism with respect to TAA-induced ALF, and male rats display dramatically poorer prognosis as compared with the females. We showed that testosterone is responsible for the deterioration of the course of TAA-induced ALF in male rats. In most general terms, our findings indicate that in the preclinical studies of the pathophysiology and treatment of ALF (at least of the TAA-induced form) the sex-linked differences should be seriously considered.

Zinc phosphate-based nanoparticles as alternatives to zinc oxide in diet of weaned piglets

BACKGROUND

The high doses of zinc oxide (ZnO) administered orally to piglets for the prevention of diarrhea and increase of growth rate can contaminate pig farms and the surrounding environment. Therefore, there is a need to find a replacement of high doses of dietary ZnO with an equally effective alternative. In the present study, the effect of two formulations of zinc phosphate-based nanoparticles (ZnA and ZnC NPs) on growth performance, intestinal microbiota, antioxidant status, and intestinal and liver morphology was evaluated. A total of 100 weaned piglets were randomly divided into 10 equal groups with the base diet (control) or the base diet supplemented with ZnA, ZnC, or ZnO at concentrations 500, 1000, and 2000 mg Zn per kilogram of diet. Supplements were given to animals for 10 days. Fecal samples were collected on day 0, 5, 10 and 20. At the end of the treatment (day 10), three piglets from each group were sacrificed and analyzed.

RESULTS

Comparing to that of control, the significantly higher piglet weight gain was observed in all piglet groups fed with ZnA (P < 0.05). Differences in the total aerobic bacteria and coliform counts in piglet feces after NPs supplementation compared to that of control and ZnO groups were also found (P < 0.05). The majority of aerobic culturable bacteria from the feces represented Escherichia (28.57-47.62%), Enterococcus (3.85-35.71%), and Streptococcus (3.70-42.31%) spp. A total of 542 Escherichia coli isolates were screened for the virulence genes STa, STb, Stx2, F4, and F18. The substantial occurrence of E. coli virulence factors was found on day 5, mainly in fimbrillary antigen and thermostable toxins, except for piglets fed by ZnC. Zn treatment decreased Zn blood levels in piglets fed with ZnO and ZnA (500 mg/kg) and increased in ZnC (2000 mg/kg) compared to that of control (P < 0.05). The antioxidant status of piglets was affected only by ZnA. While some changes in the liver and the intestinal morphology of piglets with NPs were observed, none were serious as reflected by the normal health status and increased weigh gain performance.

CONCLUSIONS

Our results indicate that ZnA NPs have a positive effect on the piglet growth performance even at the lowest concentration. The prevalence of E. coli virulence factors was lowest in pigs supplemented with ZnC. Zinc phosphate-based nanoparticles may be an effective alternative to ZnO.

Gene X environment: the cellular environment governs the transcriptional response to environmental chemicals

Background

An individual’s response to environmental exposures varies depending on their genotype, which has been termed the gene-environment interaction. The phenotype of cell exposed can also be a key determinant in the response to physiological cues, indicating that a cell-gene-environment interaction may exist. We investigated whether the cellular environment could alter the transcriptional response to environmental chemicals. Publicly available gene expression array data permitted a targeted comparison of the transcriptional response to a unique subclass of environmental chemicals that alter the activity of the estrogen receptor, xenoestrogens.

Results

Thirty xenoestrogens were included in the analysis, for which 426 human gene expression studies were identified. Comparisons were made for studies that met the predefined criteria for exposure length, concentration, and experimental replicates. The cellular response to the phytoestrogen genistein resulted in remarkably unique transcriptional profiles in breast, liver, and uterine cell-types. Analysis of gene regulatory networks and molecular pathways revealed that the cellular context mediated the activation or repression of functions important to cellular organization and survival, including opposing effects by genistein in breast vs. liver and uterine cell-types. When controlling for cell-type, xenoestrogens regulate unique gene networks and biological functions, despite belonging to the same class of environmental chemicals. Interestingly, the genetic sex of the cell-type also strongly influenced the transcriptional response to xenoestrogens in the liver, with only 22% of the genes significantly regulated by genistein common between male and female cells.

Conclusions

Our results demonstrate that the transcriptional response to environmental chemicals depends on a variety of factors, including the cellular context, the genetic sex of a cell, and the individual chemical. These findings highlight the importance of evaluating the impact of exposure across cell-types, as the effect is responsive to the cellular environment. These comparative genetic results support the concept of a cell-gene-environment interaction.

Expression of mitochondrial membrane-linked SAB determines severity of sex-dependent acute liver injury

SH3 domain-binding protein that preferentially associates with Btk (SAB) is an outer-membrane docking protein for JNK-mediated impairment of mitochondrial function. Deletion of Sab in hepatocytes inhibits sustained JNK activation and cell death. The current study demonstrates that an increase in SAB expression enhanced the severity of acetaminophen-induced (APAP-induced) liver injury. Female mice were resistant to liver injury and exhibited markedly decreased hepatic SAB protein expression compared with male mice. The mechanism of SAB repression involved a pathway from ERα to p53 expression that induced miR34a-5p. miR34a-5p targeted the Sab mRNA coding region, thereby repressing SAB expression. Fulvestrant or p53 knockdown decreased miR34a-5p and increased SAB expression in female mice, leading to increased injury from APAP and TNF/galactosamine. In contrast, an ERα agonist increased p53 and miR34a-5p, which decreased SAB expression and hepatotoxicity in male mice. Hepatocyte-specific deletion of miR34a also increased the severity of liver injury in female mice, which was prevented by GalNAc-ASO knockdown of Sab. Similar to mice, premenopausal women expressed elevated levels of hepatic p53 and low levels of SAB, whereas age-matched men expressed low levels of p53 and high levels of SAB, but there was no difference in SAB expression between the sexes in the postmenopausal stage. In conclusion, SAB expression levels determined the severity of JNK-dependent liver injury. Female mice expressed low levels of hepatic SAB protein because of the ERα/p53/miR34a pathway, which repressed SAB expression and accounted for the resistance to liver injury seen in these females.

Drug-induced liver injury

Drug-induced liver injury (DILI) is an adverse reaction to drugs or other xenobiotics that occurs either as a predictable event when an individual is exposed to toxic doses of some compounds or as an unpredictable event with many drugs in common use. Drugs can be harmful to the liver in susceptible individuals owing to genetic and environmental risk factors. These risk factors modify hepatic metabolism and excretion of the DILI-causative agent leading to cellular stress, cell death, activation of an adaptive immune response and a failure to adapt, with progression to overt liver injury. Idiosyncratic DILI is a relative rare hepatic disorder but can be severe and, in some cases, fatal, presenting with a variety of phenotypes, which mimic other hepatic diseases. The diagnosis of DILI relies on the exclusion of other aetiologies of liver disease as specific biomarkers are still lacking. Clinical scales such as CIOMS/RUCAM can support the diagnostic process but need refinement. A number of clinical variables, validated in prospective cohorts, can be used to predict a more severe DILI outcome. Although no pharmacological therapy has been adequately tested in randomized clinical trials, corticosteroids can be useful, particularly in the emergent form of DILI related to immune-checkpoint inhibitors in patients with cancer.

The role of sex in the genomics of human complex traits

Nearly all human complex traits and disease phenotypes exhibit some degree of sex differences, including differences in prevalence, age of onset, severity or disease progression. Until recently, the underlying genetic mechanisms of such sex differences have been largely unexplored. Advances in genomic technologies and analytical approaches are now enabling a deeper investigation into the effect of sex on human health traits. In this Review, we discuss recent insights into the genetic models and mechanisms that lead to sex differences in complex traits. This knowledge is critical for developing deeper insight into the fundamental biology of sex differences and disease processes, thus facilitating precision medicine.

Exposure index of methyl isocyanate (MIC) gas disaster and a comprehensive spectrum of cytogenetic analysis after 30 years

Severity of clinical expression and high mortality could not facilitate establishing exposure index/association following MIC disaster in Bhopal. Mortality-based exposure stratification was critiqued by the International Medical Commission on Bhopal (IMCB). IMCB stratified exposure considering distance as surrogate at 2 km intervals after 10 years. The first follow-up cytogenetic screening of the pre-screened survivors after 30 years has demonstrated chromosome abnormalities (CA). Exposure stratification was attempted considering cytogenetic screening conducted during 1986-1988. Elevation of CA appeared proportional to exposure status and authenticated the initial mortality-based stratification. The one-on-one comparison of the previous and present cytogenetics has described the individual response to MIC exposure over 30 years. Chi-square test has been carried out for checking the cytogenetic changes at the individual level statistically, which revealed that differences of chromosomal aberrations collected immediately post-disaster and 30 years later are nonsignificant. The prominence of interindividual variation was noticed in general. The impact of overall exposure was higher in males. Constitutional abnormalities in 8.5% of the study population, including translocation, inversion, deletion, fragile sites, etc., necessitate screening of blood-linked members. The incidence of acrocentric association was prominent in the study population. Normal karyotype in children born to severely exposed parents with congenital anomalies indicates necessity of molecular karyotyping and/or screening of mutations. The study highlights follow-up of the health of the index cases at shorter (3-6 months) intervals. This comprehensive spectrum of cytogenetic report highlights immediate post-disaster chromosomal aberrations, the changes that occurred over 30 years in conjunction with other environmental factors at the individual level, constitutive genomic aberrations, polymorphic variations, and chromosomal patterns in congenitally malformed children of the survivors, which collectively indicate the possibility of acquisition/persistence of stable aberrations in MIC-exposed lymphocytes through interaction with environmental/biological confounders.

Identifying sex differences arising from polychlorinated biphenyl exposures in toxicant-associated liver disease

Exposures to persistent environmental pollutants like polychlorinated biphenyls (PCBs) has been associated with liver diseases such as toxicant-associated steatohepatitis (TASH). However, previously published PCB hepatotoxicity studies evaluated mostly male animal models. Moreover, epidemiologic studies on PCB-exposed cohorts evaluating sex differences are scarce. Therefore, the objective of this study was to examine hepato-toxicological responses of PCB exposures in the context of sex-dependent outcomes. Male and female C57Bl/6 mice were exposed to Aroclor 1260 (20 mg/kg), and PCB126 (20 μg/kg), by gavage for two weeks. Female mice appeared to be more sensitive to PCB-induced hepatotoxic effects as manifested by increased liver injury markers, namely, hepatic Serpine1 expression. Additionally, compared to their male counterparts, PCB-exposed females exhibited dysregulated hepatic gene expression favoring lipid accumulation rather than lipid breakdown; accompanied by dyslipidemia. Sex differences were also observed in the expression and activation of PCB targets such as the epidermal growth factor receptor (EGFR) while PCB-induced pancreatic toxicity was similar in both sexes. Importantly, PCB exposure appeared to cause pro-androgenic, anti-estrogenic along with sex-dependent thyroid hormone effects. The overall findings demonstrated that the observed PCB-mediated hepatotoxicity was sex-dependent; confirming the existence of sex differences in environmental exposure-induced markers of TASH and warrants further investigation.

Long-term and mechanistic evaluation of drug-induced liver injury in Upcyte human hepatocytes

Drug-induced liver injury (DILI) constitutes one of the most frequent reasons of restricted-use warnings as well as withdrawals of drugs in postmarketing and poses an important concern for the pharmaceutical industry. The current hepatic in vivo and in vitro models for DILI detection have shown clear limitations, mainly for studies of long-term hepatotoxicity. For this reason, we here evaluated the potential of using Upcytes human hepatocytes (UHH) for repeated-dose long-term exposure to drugs. The UHH were incubated with 15 toxic and non-toxic compounds for up to 21 days using a repeated-dose approach, and, in addition to conventional examination of effects on viability, the mechanisms implicated in cell toxicity were also assessed by means of high-content screening. The UHH maintained the expression and activity levels of drug-metabolizing enzymes for up to 21 days of culture and became more sensitive to the toxic compounds after extended exposures, showing inter-donor differences which would reflect variability among the population. The assay also allowed to detect the main mechanisms implicated in the toxicity of each drug as well as identifying special susceptibilities depending on the donor. UHH can be used for a long-term repeated detection of DILI at clinically relevant concentrations and also offers key mechanistic features of drug-induced hepatotoxicity. This system is therefore a promising tool in preclinical testing of human relevance that could help to reduce and/or replace animal testing for drug adverse effects.

Toxicological Assessment of Venlafaxine: Acute and Subchronic Toxicity Study in Rats

Antidepressants are the most commonly prescribed drugs for psychiatric treatment, and venlafaxine (VEN) is one of the most popular options. Venlafaxine is a nontricyclic dual-acting serotonin-norepinephrine reuptake inhibitor. Although an increased incidence of acute toxicity and addiction has been reported, controlled studies examining its toxic effects on different organs are still lacking. This study investigated the possible toxic effects of VEN on the liver, kidney, and gastric tissues. Three groups of rats were administered saline, a single LD₅₀ dose (350 mg/kg), or 100 mg/kg VEN daily, followed by increases in the dose of 50 mg/kg every 10 days for 30 days (about 10 times the therapeutic doses). The following parameters of liver and kidney injury were then assayed: alanine aminotransferase, aspartate aminotransferase, γ-glutamyl transferase, prothrombin time, partial thromboplastin time, blood urea nitrogen, and serum creatinine. A histopathological examination was then conducted. Both acute and subchronic administration of VEN produced multiple clinical manifestations in the experimental animals, including seizures, coma, and even death. Moreover, the liver and renal function tests indicated injury in these tissues. Furthermore, the histopathological examination showed signs of organ toxicity after both acute and chronic VEN exposure. This study has shown that VEN has harmful effects on the liver, kidney, and stomach in either a single high dose (LD₅₀) or repeated exposure to 10 times the therapeutic doses. As a result, strategies to increase awareness of these effects among physicians and the public are needed because this drug may be addictive.

Reprint of: Environmental toxicology and omics: A question of sex

Molecular initiating events and downstream transcriptional/proteomic responses provide valuable information for adverse outcome pathways, which can be used predict the effects of chemicals on physiological systems. There has been a paucity of research that addresses sex-specific expression profiling in toxicology and due to cost, time, and logistic considerations, sex as a variable has not been widely considered. In response to this deficiency, federal agencies in the United States, Canada, and Europe have highlighted the importance of including sex as a variable in scientific investigations. Using case studies from both aquatic and mammalian toxicology, we report that there can be less than ~20-25% consensus in how the transcriptome and proteome of each sex responds to chemicals. Chemicals that have been shown to elicit sex-specific responses in the transcriptome or proteome include pharmaceuticals, anti-fouling agents, anticorrosive agents, and fungicides, among others. Sex-specific responses in the transcriptome and proteome are not isolated to whole animals, as investigations demonstrate that primary cell cultures isolated from each sex responds differently to toxicants. This signifies that sex is important, even in cell lines. Sex has significant implications for predictive toxicology, and both male and female data are required to improve robustness of adverse outcome pathways.

BIOLOGICAL SIGNIFICANCE

Clinical toxicology recognizes that sex is an important variable, as pharmacokinetics (ADME; absorption, distribution, metabolism, and excretion) can differ between females and males. However, few studies in toxicology have explored the implication of sex in relation to the transcriptome and proteome of whole organisms. High-throughput molecular approaches are becoming more frequently applied in toxicity screens (e.g. pre-clinical experiments, fish embryos, cell lines, synthetic tissues) and such data are expected to build upon reporter-based cell assays (e.g. receptor activation, enzyme inhibition) used in toxicant screening programs (i.e. Tox21, ToxCast, REACH). Thus, computational models can more accurately predict the diversity of adverse effects that can occur from chemical exposure within the biological system. Our studies and those synthesized from the literature suggest that the transcriptome and proteome of females and males respond quite differentially to chemicals. This has significant implications for predicting adverse effects in one sex when using molecular data generated in the other sex. While molecular initiating events are not expected to differ dramatically between females and males (i.e. an estrogen binds estrogen receptors in both sexes), it is important to acknowledge that the downstream transcriptomic and proteomic responses can differ based upon the presence/absence of co-regulators and inherent sex-specific variability in regulation of transcriptional and translational machinery. Transcriptomic and proteomic studies also reveal that cell processes affected by chemicals can differ due to sex, and this can undoubtedly lead to sex-specific physiological responses.

Pharmacokinetics of Diclofenac and Hydroxypropyl-β-Cyclodextrin (HPβCD) Following Administration of Injectable HPβCD-Diclofenac in Subjects With Mild to Moderate Renal Insufficiency or Mild Hepatic Impairment

Given their established analgesic properties, nonsteroidal anti‐inflammatory drugs (NSAIDs) represent an important postoperative pain management option. This study investigated: (1) the effects of mild or moderate renal insufficiency and mild hepatic impairment on the pharmacokinetics (PK) of diclofenac and hydroxypropyl‐β‐cyclodextrin (HPβCD) following administration of the injectable NSAID HPβCD‐diclofenac; and (2) the PK of HPβCD following administration of HPβCD‐diclofenac and intravenous itraconazole formulated with HPβCD in healthy adults. Diclofenac clearance (CL) and volume of distribution (V_z) tended to increase with decreasing renal function (moderate insufficiency versus mild insufficiency or healthy controls). Regression analysis demonstrated a significant relationship between V_z (but not CL or elimination half‐life, t_½) and renal function. HPβCD CL was significantly decreased in subjects with renal insufficiency, with a corresponding increase in t_½. There were no significant differences in diclofenac or HPβCD PK in subjects with mild hepatic impairment versus healthy subjects. Exposure to HPβCD in healthy subjects following HPβCD‐diclofenac administration was ∼12% of that with intravenous itraconazole, after adjusting for dosing schedule and predicted accumulation (<5% without adjustment). With respect to PK properties, these results suggest that HPβCD‐diclofenac might be administered to patients with mild or moderate renal insufficiency or mild hepatic impairment without dose adjustment (NCT00805090).

Sex and gender matters : A sex-specific analysis of original articles published in the Wiener klinische Wochenschrift between 2013 and 2015

BACKGROUND

The variables sex and gender are significantly related to health and disease of women and men. Aiming at quality research, biomedical publications need to account for the key variables sex and gender.

METHODS

All original articles published in the Wiener klinische Wochenschrift between 2013 and 2015 were extracted into a database. As a result, the 195 published articles were selected for review led by the Sex and Gender Equity in Research Guidelines (SAGER) by the European Association of Science Editors (EASE). The slightest indications of mentioning sex and/or gender were assessed by two reviewers independently from one another.

RESULTS

Of the 195 publications 4 specified sex and/or gender in the title, and 62 in the abstract. None of the authors reported whether the variables sex and/or gender may have relevance and were taken into account in the design of the study. Of the 195 publications 48 mentioned the potential implications of sex and/or gender on the study results.

CONCLUSION

In the time span studied most of the selected articles of this journal did not account for the variables sex and/or gender systematically or adequately. For future research the existing guidelines can help authors and editors to overcome gender bias due to inadequate methods. Applying sex and gender-sensitive methods to biomedical and health research is necessary for high quality and as a precondition for results which are generalizable and applicable to both women and men.

Dioxin Receptor Adjusts Liver Regeneration After Acute Toxic Injury and Protects Against Liver Carcinogenesis

The aryl hydrocarbon receptor (AhR) has roles in cell proliferation, differentiation and organ homeostasis, including the liver. AhR depletion induces undifferentiation and pluripotency in normal and transformed cells. Here, AhR-null mice (AhR-/-) were used to explore whether AhR controls liver regeneration and carcinogenesis by restricting the expansion of stem-like cells and the expression of pluripotency genes. Short-term CCl₄ liver damage was earlier and more efficiently repaired in AhR-/- than in AhR+/+ mice. Stem-like CK14 + and TBX3 + and pluripotency-expressing OCT4 + and NANOG + cells expanded sooner in AhR-/- than in AhR+/+ regenerating livers. Stem-like side population cells (SP) isolated from AhR-/- livers had increased β-catenin (β-Cat) signaling with overexpression of Axin2, Dkk1 and Cyclin D1. Interestingly, β-Cat, Axin2 and Dkk1 also increased during regeneration but more notably in AhR-null livers. Liver carcinogenesis induced by diethylnitrosamine (DEN) produced large carcinomas in all AhR-/- mice but mostly premalignant adenomas in less than half of AhR+/+ mice. AhR-null tumoral tissue, but not their surrounding non-tumoral parenchyma, had nuclear β-Cat and Axin2 overexpression. OCT4 and NANOG were nevertheless similarly expressed in AhR+/+ and AhR-/- lesions. We suggest that AhR may serve to adjust liver repair and to block tumorigenesis by modulating stem-like cells and β-Cat signaling.

Liver tissue fragments obtained from males are the most promising source of human hepatocytes for cell-based therapies - Flow cytometric analysis of albumin expression

Cell-based therapies that could provide an alternative treatment for the end-stage liver disease require an adequate source of functional hepatocytes. There is little scientific evidence for the influence of patient's age, sex, and chemotherapy on the cell isolation efficiency and metabolic activity of the harvested hepatocytes. The purpose of this study was to investigate whether hepatocytes derived from different sources display differential viability and biosynthetic capacity. Liver cells were isolated from 41 different human tissue specimens. Hepatocytes were labeled using specific antibodies and analyzed using flow cytometry. Multiparametric analysis of the acquired data revealed statistically significant differences between some studied groups of patients. Generally, populations of cells isolated from the male specimens had greater percentage of biosynthetically active hepatocytes than those from the female ones regardless of age and previous chemotherapy of the patient. Based on the albumin staining (and partially on the α-1-antitrypsin labeling) after donor liver exclusion (6 out of 41 samples), our results indicated that: 1. samples obtained from males gave a greater percentage of active hepatocytes than those from females (p = 0.034), and 2. specimens from the males after chemotherapy greater than those from the treated females (p = 0.032).

A Pathway to Personalizing Therapy for Metastases Using Liver-on-a-Chip Platforms

Metastasis accounts for most cancer-related deaths. The majority of solid cancers, including those of the breast, colorectum, prostate and skin, metastasize at significant levels to the liver due to its hemodynamic as well as tumor permissive microenvironmental properties. As this occurs prior to detection and treatment of the primary tumor, we need to target liver metastases to improve patients' outcomes. Animal models, while proven to be useful in mechanistic studies, do not represent the heterogeneity of human population especially in drug metabolism lack proper human cell-cell interactions, and this gap between animals and humans results in costly and inefficient drug discovery. This underscores the need to accurately model the human liver for disease studies and drug development. Further, the occurrence of liver metastases is influenced by the primary tumor type, sex and race; thus, modeling these specific settings will facilitate the development of personalized/targeted medicine for each specific group. We have adapted such all-human 3D ex vivo hepatic microphysiological system (MPS) (a.k.a. liver-on-a-chip) to investigate human micrometastases. This review focuses on the sources of liver resident cells, especially the iPS cell-derived hepatocytes, and examines some of the advantages and disadvantages of these sources. In addition, this review also examines other potential challenges and limitations in modeling human liver.

2015 Lush Science Prize

The Lush Prize supports animal-free testing by rewarding the most effective projects and individuals who have been working toward the goal of replacing animals in product or ingredient safety testing. Prizes are awarded for developments in five strategic areas: Science; Lobbying; Training; Public Awareness; and Young Researchers. Should there be a major breakthrough in 21st century toxicology, a Black Box Prize equivalent to the entire annual fund of £250,000 is awarded. A Background Paper is prepared each year, prior to the judging process, to provide the panel with a brief overview of current developments in the field of Replacement alternatives, particularly those relevant to the concept of toxicity pathways. The Background Paper includes information on recent work by the relevant scientific institutions and projects in this area, including AXLR8, the OECD, The Hamner Institutes, the Human Toxome Project, EURL ECVAM, ICCVAM, the US Tox21 Programme, the ToxCast programme, and the Human Toxicology Project Consortium. Recent developments in toxicity pathway research are also assessed by reviewing the relevant literature (including conference proceedings), and the abstracts and papers receiving the highest score are presented to the judges for consideration.

Acetaminophen-Induced Hepatotoxicity: a Comprehensive Update

Hepatic injury and subsequent hepatic failure due to both intentional and non-intentional overdose of acetaminophen (APAP) has affected patients for decades, and involves the cornerstone metabolic pathways which take place in the microsomes within hepatocytes. APAP hepatotoxicity remains a global issue; in the United States, in particular, it accounts for more than 50% of overdose-related acute liver failure and approximately 20% of the liver transplant cases. The pathophysiology, disease course and management of acute liver failure secondary to APAP toxicity remain to be precisely elucidated, and adverse patient outcomes with increased morbidity and mortality continue to occur. Although APAP hepatotoxicity follows a predictable timeline of hepatic failure, its clinical presentation might vary. N-acetylcysteine (NAC) therapy is considered as the mainstay therapy, but liver transplantation might represent a life-saving procedure for selected patients. Future research focus in this field may benefit from shifting towards obtaining antidotal knowledge at the molecular level, with focus on the underlying molecular signaling pathways.

Cytotoxicity evaluation using cryopreserved primary human hepatocytes in various culture formats

Sixteen training compounds selected in the IMI MIP-DILI consortium, 12 drug-induced liver injury (DILI) positive compounds and 4 non-DILI compounds, were assessed in cryopreserved primary human hepatocytes. When a ten-fold safety margin threshold was applied, the non-DILI-compounds were correctly identified 2h following a single exposure to pooled human hepatocytes (n=13 donors) in suspension and 14-days following repeat dose exposure (3 treatments) to an established 3D-microtissue co-culture (3D-MT co-culture, n=1 donor) consisting of human hepatocytes co-cultured with non-parenchymal cells (NPC). In contrast, only 5/12 DILI-compounds were correctly identified 2h following a single exposure to pooled human hepatocytes in suspension. Exposure of the 2D-sandwich culture human hepatocyte monocultures (2D-sw) for 3days resulted in the correct identification of 11/12 DILI-positive compounds, whereas exposure of the human 3D-MT co-cultures for 14days resulted in identification of 9/12 DILI-compounds; in addition to ximelagatran (also not identified by 2D-sw monocultures, Sison-Young et al., 2016), the 3D-MT co-cultures failed to detect amiodarone and bosentan. The sensitivity of the 2D human hepatocytes co-cultured with NPC to ximelagatran was increased in the presence of lipopolysaccharide (LPS), but only at high concentrations, therefore preventing its classification as a DILI positive compound. In conclusion (1) despite suspension human hepatocytes having the greatest metabolic capacity in the short term, they are the least predictive of clinical DILI across the MIP-DILI test compounds, (2) longer exposure periods than 72h of human hepatocytes do not allow to increase DILI-prediction rate, (3) co-cultures of human hepatocytes with NPC, in the presence of LPS during the 72h exposure period allow the assessment of innate immune system involvement of a given drug.

Impact of Environmental Chemicals on the Transcriptome of Primary Human Hepatocytes: Potential for Health Effects

New paradigms for human health risk assessment of environmental chemicals emphasize the use of molecular methods and human-derived cell lines. In this study, we examined the effects of the insect repellent DEET (N,N-diethyl-m-toluamide) and the phenylpyrazole insecticide fipronil (fluocyanobenpyrazole) on transcript levels in primary human hepatocytes. These chemicals were tested individually and as a mixture. RNA-Seq showed that 100 μM DEET significantly increased transcript levels (α = 0.05) for 108 genes and lowered transcript levels for 64 genes and fipronil at 10 μM increased the levels of 2246 transcripts and decreased the levels for 1428 transcripts. Fipronil was 21-times more effective than DEET in eliciting changes, even though the treatment concentration was 10-fold lower for fipronil versus DEET. The mixture of DEET and fipronil produced a more than additive effect (levels increased for 3017 transcripts and decreased for 2087 transcripts). The transcripts affected for all chemical treatments were classified by GO analysis and mapped to chromosomes. The overall treatment responses, specific pathways, and individual transcripts affected were discussed at different levels of fold-change. Changes found in transcript levels in response to treatments will require further research to understand their importance in overall cellular, organ, and organismic function.

Sex-Related Differences of Lipid Metabolism Induced by Triptolide: The Possible Role of the LXRα/SREBP-1 Signaling Pathway

Triptolide, a diterpenoid isolated from the plant Tripterygium wilfordii Hook. f., exerts a unique bioactive spectrum of anti-inflammatory and anticancer activities. However, triptolide's clinical applications are limited due to its severe toxicities. Fatty liver toxicity occurs in response to triptolide, and this toxic response significantly differs between males and females. This report investigated the pathogenesis underlying the sex-related differences in the dyslipidosis induced by triptolide in rats. Wistar rats were administered 0, 150, 300, or 450 μg triptolide/kg/day by gavage for 28 days. Ultrastructural examination revealed that more lipid droplets were present in female triptolide-treated rats than in male triptolide-treated rats. Furthermore, liver triglyceride, total bile acid and free fatty acid levels were significantly increased in female rats in the 300 and 450 μg/kg dose groups. The expression of liver X receptor α (LXRα) and its target genes, cholesterol 7α-hydroxylase (CYP7A1) and Sterol regulatory element-binding transcription factor 1(SREBP-1), increased following triptolide treatment in both male and female rats; however, the female rats were more sensitive to triptolide than the male rats. In addition, the expression of acetyl-CoA carboxylase 1(ACC1), a target gene of SREBP-1, increased in the female rats treated with 450 μg triptolide/kg/day, and ACC1 expression contributed to the sex-related differences in the triptolide-induced dysfunction of lipid metabolism. Our results demonstrate that the sex-related differences in LXR/SREBP-1-mediated regulation of gene expression in rats are responsible for the sex-related differences in lipid metabolism induced by triptolide, which likely underlie the sex-related differences in triptolide hepatotoxicity. This study will be important for predicting sex-related effects on the pharmacokinetics and toxicity of triptolide and for improving its safety.