Roles of ERRα and TGF-β signaling in stemness enhancement induced by 1 µM bisphenol A exposure via human neural stem cells

Recent advances in environmental toxicology: Exploring gene editing, organ-on-a-chip, chimeric animals, and in silico models

In our daily life, we are exposed to various environmental pollutants in multiple ways. At present, we mainly rely on animal models and two-dimensional cell culture models to evaluate the toxicity of environmental pollutants. Nevertheless, results in animal models do not always apply to humans because of differences between species, while two-dimensional cell culture models cannot replicate the in vivo microenvironments, making it difficult to predict the true toxic response of environmental pollutants in humans. The development of various high-end technologies in recent years has provided new opportunities for environmental toxicology research. The application of these high-end technologies in environmental toxicology can complement the limitations of traditional environmental toxicology screening and more accurately predict the toxicity of environmental pollutants. In this review, we first introduce the advantages and disadvantages of traditional environmental toxicology methods, then review the principles and development of four high-end technologies, such as gene editing, organ-on-a-chip, chimeric animals, and in silico models, summarize their application in toxicity testing, and finally emphasize their importance/potential in environmental toxicology.

Induction of fibrosis following exposure to bisphenol A and its analogues in 3D human uterine leiomyoma cultures

Bisphenol A (BPA) and its analogues (BPAF, BPS) are ubiquitous environmental contaminants used as plastic additives in various daily life products, with many concerns on their role as environmental estrogens. Uterine leiomyomas (fibroids) are highly prevalent gynecologic tumors with progressive fibrosis. Fibroids are hormone-responsive and may be the target of environmental estrogens. However, the effects of BPA, BPAF, and BPS exposure on uterine fibrosis are largely unknown. Here, we evaluated fibrosis and the crucial role of TGF-beta signaling in human fibroid tumors, the profibrotic effects of BPA, BPAF or BPS in a human 3D uterine leiomyoma (ht-UtLM) in vitro model, and the long-term outcomes of BPAF exposure in rat uterus. In 3D ht-UtLM spheroids, BPA, BPAF, and BPS all promoted cell proliferation and fibrosis by increasing the production of extracellular matrices. Further mechanistic analysis showed the profibrotic effects were induced by TGF-beta signaling activation mainly through SMAD2/3 pathway and crosstalk with multiple non-SMAD pathways. Furthermore, the profibrotic effects of BPAF were supported by observation of uterine fibrosis in vivo in rats following long-term BPAF exposure. Overall, the 3D ht-UtLM spheroid can be an important model for investigating environment-induced fibrosis in uterine fibroids. BPA and its analogues can induce fibrosis via TGF-beta signaling.

Data of RNA-seq transcriptomes of gastrocnemius muscle, epididymal adipose tissue in obese rats under normoxia/hypoxic exercise environments

Studies on the crosstalk between muscle and adipose tissue can provide beneficial help in elucidating the pathogenesis and treatment of obesity-related diseases [1]. In this data article, we performed RNA sequence analysis of mRNA isolated from epididymal adipose tissue and gastrocnemius muscle tissue in obese rats. Twenty-two samples were selected for gene expression analysis. Raw data from the Illumina Hiseq™ platform sequencer was used for differential gene expression analysis using DESeq and deposited in the GEO public repository under accession number GSE237950. With the economic development and the change of people's lifestyle, obesity has become a major public health problem that endangers global health. Obesity is a metabolic disorder caused by excessive accumulation of white adipose tissue, which can further induce metabolic syndrome such as insulin resistance, type 2 diabetes, and cardiovascular and cerebrovascular diseases. Studies have shown that altitude hypoxic exercise can not only improve muscle buffering capacity and body performance, but also reduce body weight and body fat more significantly. In many countries, it has been used as a treatment program for obesity diseases [2]. Hypoxic exercise can improve lipid metabolism, reduce blood lipid levels, inhibit fatty acid synthesis, and promote fatty acid decomposition and oxidation, which is the mechanism of hypoxic exercise to significantly reduce weight and fat. However, the mechanism of the cross-talk between muscle and fat tissue is not well understood under hypoxia exercise and normoxia exercise conditions. The data contained rat's four different states: normoxia quiet, normoxia exercise, hypoxic quiet, and hypoxic exercise. RNA-seq data will provide insights into the cross-talk between muscle and fat, and the mechanisms of fat metabolism. The data of this study have not been published and are hereby published on this platform to study the cross talk between muscle tissue and adipose tissue in rats under different oxygen content and exercise environment.

Modeling early human cortical development and evaluating neurotoxicity with a forebrain organoid system

The complexity and subtlety of brain development renders it challenging to examine effects of environmental toxicants on human fetal brain development. Advances in pluripotent cell-derived organoid systems open up novel avenues for human development, disease and toxicity modeling. Here, we have established a forebrain organoid system and recapitulated early human cortical development spatiotemporally including neuroepithelium induction, apical-basal axis formation, neural progenitor proliferation and maintenance, neuronal differentiation and layer/region patterning. To explore whether this forebrain organoid system is suitable for neurotoxicity modeling, we subjected the organoids to bisphenol A (BPA), a common environmental toxicant of global presence and high epidemic significance. BPA exposure caused substantial abnormalities in key cortical developmental events, inhibited progenitor cell proliferation and promoted precocious neuronal differentiation, leading premature progenitor cell depletion and aberrant cortical layer patterning and structural organization. Consistent with an antagonistic mechanism between thyroid hormone and BPA, T3 supplementation attenuated BPA-mediated cortical developmental abnormalities. Altogether, our in vitro recapitulation of cortical development with forebrain organoids provides a paradigm for efficient neural development and toxicity modeling and related remedy testing/screening.

Proteomics and disease network associations evaluation of environmentally relevant Bisphenol A concentrations in a human 3D neural stem cell model

Bisphenol A (BPA) exposure is associated with a plethora of neurodevelopmental abnormalities and brain disorders. Previous studies have demonstrated BPA-induced perturbations to critical neural stem cell (NSC) characteristics, such as proliferation and differentiation, although the underlying molecular mechanisms remain under debate. The present study evaluated the effects of a repeated-dose exposure of environmentally relevant BPA concentrations during the in vitro 3D neural induction of human induced pluripotent stem cells (hiPSCs), emulating a chronic exposure scenario. Firstly, we demonstrated that our model is suitable for NSC differentiation during the early stages of embryonic brain development. Our morphological image analysis showed that BPA exposure at 0.01, 0.1 and 1 µM decreased the average spheroid size by day 21 (D21) of the neural induction, while no effect on cell viability was detected. No alteration to the rate of the neural induction was observed based on the expression of key neural lineage and neuroectodermal transcripts. Quantitative proteomics at D21 revealed several differentially abundant proteins across all BPA-treated groups with important functions in NSC proliferation and maintenance (e.g., FABP7, GPC4, GAP43, Wnt-8B, TPPP3). Additionally, a network analysis demonstrated alterations to the glycolytic pathway, potentially implicating BPA-induced changes to glycolytic signalling in NSC proliferation impairments, as well as the pathophysiology of brain disorders including intellectual disability, autism spectrum disorders, and amyotrophic lateral sclerosis (ALS). This study enhances the current understanding of BPA-related NSC aberrations based mostly on acute, often high dose exposures of rodent in vivo and in vitro models and human GWAS data in a novel human 3D cell-based model with real-life scenario relevant prolonged and low-level exposures, offering further mechanistic insights into the ramifications of BPA exposure on the developing human brain and consequently, later life neurological disorders.

Does Bisphenol A Confer Risk of Neurodevelopmental Disorders? What We Have Learned from Developmental Neurotoxicity Studies in Animal Models

Substantial evidence indicates that bisphenol A (BPA), a ubiquitous environmental chemical used in the synthesis of polycarbonate plastics and epoxy resins, can impair brain development. Clinical and epidemiological studies exploring potential connections between BPA and neurodevelopmental disorders in humans have repeatedly identified correlations between early BPA exposure and developmental disorders, such as attention deficit/hyperactivity disorder and autism spectrum disorder. Investigations using invertebrate and vertebrate animal models have revealed that developmental exposure to BPA can impair multiple aspects of neuronal development, including neural stem cell proliferation and differentiation, synapse formation, and synaptic plasticity-neuronal phenotypes that are thought to underpin the fundamental changes in behavior-associated neurodevelopmental disorders. Consistent with neuronal phenotypes caused by BPA, behavioral analyses of BPA-treated animals have shown significant impacts on behavioral endophenotypes related to neurodevelopmental disorders, including altered locomotor activity, learning and memory deficits, and anxiety-like behavior. To contextualize the correlations between BPA and neurodevelopmental disorders in humans, this review summarizes the current literature on the developmental neurotoxicity of BPA in laboratory animals with an emphasis on neuronal phenotypes, molecular mechanisms, and behavioral outcomes. The collective works described here predominantly support the notion that gestational exposure to BPA should be regarded as a risk factor for neurodevelopmental disorders.