Exposure to bisphenol A associated with multiple health-related outcomes in humans: An umbrella review of systematic reviews with meta-analyses

1,25‑Dihydroxyvitamin D3 mitigates the adipogenesis induced by bisphenol A in 3T3-L1 and hAMSC through miR-27-3p regulation

PURPOSE

Endocrine-disrupting compounds, including bisphenol A (BPA), may promote obesity influencing basal metabolic rate and shifting metabolism towards energy storage. The role of 1,25‑Dihydroxyvitamin D3 (VitD) in counteracting adipogenesis is still a matter of debate. Thus, the current study aims to investigate whether and how VitD exposure during adipogenesis could prevent the pro-adipogenic effect of BPA in two adipocyte models, mouse 3T3-L1 cell line and human adipose-derived mesenchymal stem cells (hAMSC).

METHODS

3T3-L1, mouse pre-adipocytes and human adipose-derived mesenchymal stem cells (hAMSC) were treated with VitD (10-7 M) and BPA (10-8 M and 10-9 M), alone or in combination, throughout the differentiation in mature adipocytes. Cellular lipid droplet accumulation was assessed by Oil Red O staining, mRNA and protein expression of key adipogenic markers, transcription factors, and cytokines were investigated by RT-qPCR and WB, respectively. miRNAs involved in the regulation of adipogenic transcription factors were evaluated by RT-qPCR, and highly potent steric-blocking oligonucleotides (miRNA inhibitors) were used to modulate miRNAs expression.

RESULTS

Pre-adipocytes express VitD receptor (VDR) in basal condition, but during the differentiation process VDR expression reduces if not stimulated by the ligand. VitD significantly decreases lipid accumulation, with a consequent reduction in adipogenic marker expression, and counteracts the pro-adipogenic effect of BPA in 3T3-L1 and hAMSC during differentiation. This effect is associated to the increased expression of miR-27a-3p and miR-27b-3p. The blocking of miR-27a-3p and miR-27b-3p through miRNA inhibitors prevents the anti-adipogenic effect of VitD in both cell models.

CONCLUSIONS

These results suggest that in cultured 3T3-L1 and hAMSC VitD induces an anti-adipogenic effect and prevents BPA pro-adipogenic effect by triggering at least in part epigenetic mechanisms involving miR-27-3p.

An Umbrella Review of Meta-Analyses Evaluating Associations between Human Health and Exposure to Major Classes of Plastic-Associated Chemicals

Background: Epidemiological research investigating the impact of exposure to plastics, and plastic-associated chemicals, on human health is critical, especially given exponentially increasing plastic production. In parallel with increasing production, academic research has also increased exponentially both in terms of the primary literature and ensuing systematic reviews with meta-analysis. However, there are few overviews that capture a broad range of chemical classes to present a state of play regarding impacts on human health. Methods: We undertook an umbrella review to review the systematic reviews with meta-analyses. Given the complex composition of plastic and the large number of identified plastic-associated chemicals, it was not possible to capture all chemicals that may be present in, and migrate from, plastic materials. We therefore focussed on a defined set of key exposures related to plastics. These were microplastics, due to their ubiquity and potential for human exposure, and the polymers that form the matrix of consumer plastics. We also included plasticisers and flame retardants as the two classes of functional additive with the highest concentration ranges in plastic. In addition, we included bisphenols and per- and polyfluoroalkyl substances (PFAS) as two other major plastic-associated chemicals with significant known exposure through food contact materials. Epistemonikos and PubMed were searched for systematic reviews with meta-analyses, meta-analyses, and pooled analyses evaluating the association of plastic polymers, particles (microplastics) or any of the selected groups of high-volume plastic-associated chemicals above, measured directly in human biospecimens, with human health outcomes. Results: Fifty-two systematic reviews were included, with data contributing 759 meta-analyses. Most meta-analyses (78%) were from reviews of moderate methodological quality. Across all the publications retrieved, only a limited number of plastic-associated chemicals within each of the groups searched had been evaluated in relevant meta-analyses, and there were no meta-analyses evaluating polymers, nor microplastics. Synthesised estimates of the effects of plastic-associated chemical exposure were identified for the following health outcome categories in humans: birth, child and adult reproductive, endocrine, child neurodevelopment, nutritional, circulatory, respiratory, skin-related and cancers. Bisphenol A (BPA) is associated with decreased anoclitoral distance in infants, type 2 diabetes (T2D) in adults, insulin resistance in children and adults, polycystic ovary syndrome, obesity and hypertension in children and adults and cardiovascular disease (CVD); other bisphenols have not been evaluated. Phthalates, the only plasticisers identified, are associated with spontaneous pregnancy loss, decreased anogenital distance in boys, insulin resistance in children and adults, with additional associations between certain phthalates and decreased birth weight, T2D in adults, precocious puberty in girls, reduced sperm quality, endometriosis, adverse cognitive development and intelligence quotient (IQ) loss, adverse fine motor and psychomotor development and elevated blood pressure in children and asthma in children and adults. Polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) but not other flame retardants, and some PFAS were identified and are all associated with decreased birth weight. In general populations, PCBs are associated with T2D in adults and endometriosis, bronchitis in infants, CVD, non-Hodgkin's lymphoma (NHL) and breast cancer. In PCB-poisoned populations, exposure is associated with overall mortality, mortality from hepatic disease (men), CVD (men and women) and several cancers. PBDEs are adversely associated with children's cognitive development and IQ loss. PBDEs and certain PFAS are associated with changes in thyroid function. PFAS exposure is associated with increased body mass index (BMI) and overweight in children, attention deficit hyperactive disorder (ADHD) in girls and allergic rhinitis. Potential protective associations were found, namely abnormal pubertal timing in boys being less common with higher phthalate exposure, increased high-density lipoprotein (HDL) with exposure to mono(2-ethyl-5-oxohexyl) phthalate (MEOHP) and reduced incidence of chronic lymphocytic lymphoma (a subtype of NHL) with PCB exposure. Conclusions: Exposure to plastic-associated chemicals is associated with adverse outcomes across a wide range of human health domains, and every plastic-associated chemical group is associated with at least one adverse health outcome. Large gaps remain for many plastic-associated chemicals. Recommendations: For research, we recommend that efforts are harmonised globally to pool resources and extend beyond the chemicals included in this umbrella review. Priorities for primary research, with ensuing systematic reviews, could include micro- and nanoplastics as well as emerging plastic-associated chemicals of concern such as bisphenol analogues and replacement plasticisers and flame retardants. With respect to chemical regulation, we propose that safety for plastic-associated chemicals in humans cannot be assumed at market entry. We therefore recommend that improved independent, systematic hazard testing for all plastic-associated chemicals is undertaken before market release of products. In addition because of the limitations of laboratory-based testing for predicting harm from plastic in humans, independent and systematic post-market bio-monitoring and epidemiological studies are essential to detect potential unforeseen harms.

Concentrations, sources and health risk of bisphenols in red swamp crayfish (Procambarus clarkii) from South-Eastern China

Bisphenol analogs (BPs) are extensively employed in commercial and industrial products and they have been found in a variety of environmental matrices and human samples. The red swamp crayfish (Procambarus clarkii) has been a trendy food in China in recent decades. However, the levels of BPs in Chinese crayfish and the associated hazards of human exposure remain unknown. Thus, in this study, the levels of eight BPs in crayfish gathered from five major provinces engaged in crayfish within the Yangtze River Basin were analyzed. Additionally, the health risks for humans by ingesting crayfish were calculated. BPs were frequently detected in crayfish tissues, indicating the wide occurrence of these chemicals. In comparison to other substitutions, BPA remains the dominant bisphenol analog. Most of the BPs were observed to accumulate in the hepatopancreas compared to the muscle, so consuming the hepatopancreas of crayfish is not recommended. With the exception of BPS, the Estimated Daily Intakes (EDIs) of the remaining BPs exceeded the Tolerable Daily Intake (TDI) specified by the European Food Safety Authority (EFSA) by a factor of 1.75-69.0. The mean hazard index (HI) values exceeded 1 for both hepatopancreas and muscle in all provinces, and the mean HI values for hepatopancreas were significantly higher than those for muscle, indicating potential health risks for local consumers.

No Differences in Urine Bisphenol A Concentrations between Subjects Categorized with Normal Cognitive Function and Mild Cognitive Impairment Based on Montreal Cognitive Assessment Scores

A link between bisphenol A (BPA) exposure and cognitive disorders has been suggested. However, the differences in BPA concentrations between subjects with and without cognitive impairment have not been analysed. Therefore, this observational study aimed to compare urine BPA levels in subjects with normal cognitive function (NCF) and mild cognitive impairment (MCI). A total of 89 MCI subjects and 89 well-matched NCF individuals were included in this study. Cognitive functions were assessed using the Montreal Cognitive Assessment (MOCA) scale. Urine BPA concentrations were evaluated by gas chromatography-mass spectrometry and adjusted for creatinine levels. Moreover, anthropometric parameters, body composition, sociodemographic factors, and physical activity were also assessed. Creatinine-adjusted urine BPA levels did not differ between the NCF and MCI groups (1.8 (1.4-2.7) vs. 2.2 (1.4-3.6) µg/g creatinine, p = 0.1528). However, there were significant differences in MOCA results between groups when the study population was divided into tertiles according to BPA concentrations (p = 0.0325). Nevertheless, multivariate logistic regression demonstrated that only education levels were independently associated with MCI. In conclusion, urine BPA levels are not significantly different between subjects with MCI and NCF, but these findings need to be confirmed in further studies.

Endocrine-disrupting compounds and their impact on human placental function: evidence from placenta organ-on-chip studies

The effects of endocrine-disrupting compounds (EDCs) on the placenta, a critical gestational organ for xenobiotic protection, are well reported; however, models to determine the role of EDCs in placental disruption are limited. An advanced 2nd-trimester human placenta organ-on-chip model (2TPLA-OOC) was developed and validated, with six representative cells of the maternal and the fetal interface interconnected with microchannels. Various EDCs (150 ng mL-1 each of bisphenol A, bisphenol S, and polybrominated diphenyl ethers-47 and -99) were gradually propagated across the chip for 72 hours, and their various effects were determined. Cigarette smoke extract (CSE), an environmental risk factor, was used as a positive control. EDCs produced overall oxidative stress in the placental/decidual cells, induced cell-specific endocrine effects, caused limited (<10%) apoptosis/necrosis in trophoblasts and mesenchymal cells, induced localized inflammation but an overall anti-inflammatory shift, did not change immune cell migration from stroma to decidua, and did not affect placental nutrient transport. Overall, (1) the humanized 2TPLA-OOC recreated the placental organ and generated data distinct from the trophoblast and other cells studied in isolation, and (2) at doses associated with adverse pregnancies, EDCs produced limited and localized insults, and the whole organ compensated for the exposure.

TAN (tannic acid) inhibits BPA-induced pyroptosis of L8824 (grass carp hepatocytes) by regulating PTEN/PI3K/AKT pathway

Bisphenol A (BPA) and its analogues are still one of the most important substances that pollute aquatic systems and pose a threat to aquatic organisms. Tannic acid (TAN) is a kind of glycosyl compound, which has the functions of anti-oxidation, anti-inflammation and anti-apoptosis. However, it is unknown if BPA can regulate PTEN/PI3K/AKT pathway to induce pyroptosis of grass carp hepatocytes (L8824) and the antagonistic effect of tannic acid (TAN) through oxidative stress. Therefore, we established the grass carp hepatocytes (L8824) cell model treated with BPA. The oxidative stress indexes (SOD, CAT, GSH, H2O2 and T-AOC) were detected by oxidative stress kit, mRNA and protein expression of associated genes were examined using qRT-PCR and western blotting. The results showed that BPA treatment increased the content of hydrogen peroxide and decreased the activities of antioxidant enzymes and antioxidants (SOD, CAT, GSH, and T-AOC) in L8824 cells. We also found that PTEN/PI3K/AKT pathway was activated dramatically and the expression of pyroptosis-related genes (GSDMD, NLRP3, Caspase1, ASC and IL-1β) was increased significantly. In addition, TAN could significantly reduce the toxicity of BPA on L8824 cells. After the addition of PTEN specific inhibitor SF1670, the activation of PTEN/PI3K/AKT pathway decreased by BPA was inhibited and the expression of scorch related genes was decreased. On the whole, TAN inhibits BPA-induced pyroptosis of L8824 by modulating the PTEN/PI3K/AKT pathway. The present study provides a novel perspective for toxicological mechanism of BPA, and new insights into the detoxification mechanism of TAN.

The Role of Endocrine Disruptors Bisphenols and Phthalates in Obesity: Current Evidence, Perspectives and Controversies

Excess body weight constitutes one of the major health challenges for societies and healthcare systems worldwide. Besides the type of diet, calorie intake and the lack of physical exercise, recent data have highlighted a possible association between endocrine-disrupting chemicals (EDCs), such as bisphenol A, phthalates and their analogs, and obesity. EDCs represent a heterogeneous group of chemicals that may influence the hormonal regulation of body mass and adipose tissue morphology. Based on the available data from mechanistic, animal and epidemiological studies including meta-analyses, the weight of evidence points towards the contribution of EDCs to the development of obesity, associated disorders and obesity-related adipose tissue dysfunction by (1) impacting adipogenesis; (2) modulating epigenetic pathways during development, enhancing susceptibility to obesity; (3) influencing neuroendocrine signals responsible for appetite and satiety; (4) promoting a proinflammatory milieu in adipose tissue and inducing a state of chronic subclinical inflammation; (5) dysregulating gut microbiome and immune homeostasis; and (6) inducing dysfunction in thermogenic adipose tissue. Critical periods of exposure to obesogenic EDCs are the prenatal, neonatal, pubertal and reproductive periods. Interestingly, EDCs even at low doses may promote epigenetic transgenerational inheritance of adult obesity in subsequent generations. The aim of this review is to summarize the available evidence on the role of obesogenic EDCs, specifically BPA and phthalate plasticizers, in the development of obesity, taking into account in vitro, animal and epidemiologic studies; discuss mechanisms linking EDCs to obesity; analyze the effects of EDCs on obesity in critical chronic periods of exposure; and present interesting perspectives, challenges and preventive measures in this research area.

Bisphenol A analogues and metabolic syndrome in women with polycystic ovary syndrome

Bisphenols (BPs) have become a chemical group of special interest due to their ability to interfere with the endocrine system and their ubiquitous presence in the environment. As some of them possess mild estrogenic and anti-androgenic effects, they might be associated with the diagnosis of polycystic ovary syndrome (PCOS). Acting on multiple tissues, BPs exposure may lead to metabolic derangements characteristic for metabolic syndrome (MetS). Therefore, the aim of this study was to determine the potential relationship between exposure to some BPA analogues and features of the MetS in women with PCOS. Serum BPE, BPC, BPG, BPM, BPP, BPZ, BPFL, and BPBP concentrations did not differ significantly between the PCOS (n = 135) and the control subjects (n = 104). However, women whose serum BPM and BPP concentrations were in the highest tertile were more likely to be diagnosed with PCOS (adjusted OR; [95%CI] 0.43; [0.20; 0.89], P < 0.001 and 0.56; [0.27; 0.96], P = 0.049, consequently). Serum concentrations of BPs were not associated with the MetS diagnosis in the PCOS group. There was a negative correlation between the concentrations of serum BPBP and total serum cholesterol (r = - 0.153; P = 0.019), BPE and serum testosterone (r = - 0.160; P = 0.014) as well as BPC and HDL-cholesterol (r = - 0.138; P = 0.036). There was a positive correlation between the concentrations of BPP and serum triglycerides (r = 0.138; P = 0.036). Our results point to the potential association between exposure to BPM, BPP, and the diagnosis of PCOS, along with the impact of BPBP, BPE, BPC, and BPP on the metabolic features of the MetS.