Public health concern behind the exposure to persistent organic pollutants and the risk of metabolic diseases

Emerging technologies for the removal of pesticides from contaminated soils and their reuse in agriculture

Pesticides are becoming more prevalent in agriculture to protect crops and increase crop yields. However, nearly all pesticides used for this purpose reach non-target crops and remain as residues for extended periods. Contamination of soil by widespread pesticide use, as well as its toxicity to humans and other living organisms, is a global concern. This has prompted us to find solutions and develop alternative remediation technologies for sustainable management. This article reviews recent technological developments for remediating pesticides from contaminated soil, focusing on the following major points: (1) The application of various pesticide types and their properties, the sources of pesticides related to soil pollution, their transport and distribution, their fate, the impact on soil and human health, and the extrinsic and intrinsic factors that affect the remediation process are the main points of focus. (2) Sustainable pesticide degradation mechanisms and various emerging nano- and bioelectrochemical soil remediation technologies. (3) The feasible and long-term sustainable research and development approaches that are required for on-site pesticide removal from soils, as well as prospects for applying them directly in agricultural fields. In this critical analysis, we found that bioremediation technology has the potential for up to 90% pesticide removal from the soil. The complete removal of pesticides through a single biological treatment approach is still a challenging task; however, the combination of electrochemical oxidation and bioelectrochemical system approaches can achieve the complete removal of pesticides from soil. Further research is required to remove pesticides directly from soils in agricultural fields on a large-scale.

Opportunities offered by latent-based multiblock strategies to integrate biomarkers of chemical exposure and biomarkers of effect in environmental health studies

Modern environmental epidemiology benefits from a new generation of technologies that enable comprehensive profiling of biomarkers, including environmental chemical exposure and omic datasets. The integration and analysis of large and structured datasets to identify functional associations is constrained by computational challenges that cannot be overcome using conventional regression methods. Some extensions of Partial Least Squares (PLS) regression have been developed to efficently integrate multiple datasets, including Multiblock PLS (MB-PLS) and Sequential and Orthogonalized PLS; however, these approaches remain seldom applied in environmental epidemiology. To address that research gap, this study aimed to assess and compare the applicability of PLS-based multiblock models in an observational case study, where biomarkers of exposure to environmental chemicals and endogenous biomarkers of effect were simultaneously integrated to highlight biological links related to a health outcome. The methods were compared with and without sparsity coupling two metrics to support the variable selection: Variable Importance in Projection (VIP) and Selectivity Ratio (SR). The framework was applied to a case-study dataset mimicking the structure of 36 environmental exposure biomarkers (E-block), 61 inflammation biomarkers (M-block), and their relationships with the gestational age at delivery of 161 mother-infant pairs. The results showed an overall consistency in the selected variables across models, although some specific selection patterns were identified. The block-scaled concatenation-based approaches (e.g. MB-PLS) tended to select more variables from the E-block, while these methods were unable to identify certain variables in the M-block. Overall, the number of variables selected using the SR criterion was higher than using the VIP criterion, with lower predictive performances. The multiblock models coupled to VIP, appeared to be the methods of choice for identifying relevant variables with similar statistical performances. Overall, the use of multiblock PLS-based methods appears to be a good strategy to efficiently support the variable selection process in modern environmental epidemiology.

Seeing Beyond the Smoke: Selecting Waterpipe Wastewater Chemicals for Risk Assessments

Background

Increasing use prevalence of waterpipe tobacco smoking raises concerns about environmental impacts from waterpipe waste disposal. The U.S. Food and Drug Administration (FDA) is required to assess the environmental impact of its tobacco regulatory actions per the National Environmental Policy Act. This study builds on FDA's efforts characterizing the aquatic toxicity of waterpipe wastewater chemicals.

Methods

We compiled a comprehensive list of waterpipe wastewater chemical concentrations from literature. We then selected chemicals for risk assessment by estimating persistence, bioaccumulation, and aquatic toxicity characteristics (PBT; U.S. Environmental Protection Agency), and hazardous concentration values (concentration affecting specific proportion of species).

Results

Of 38 chemicals in waterpipe wastewater with concentration data, 20 are listed as harmful or potentially harmful constituents (HPHCs) in tobacco smoke and tobacco products by FDA, and 15 are hazardous waste per U. S. Environmental Protection Agency. Among metals, six (cadmium, chromium, lead, mercury, nickel and selenium) are included in both HPHC and hazardous waste lists and were selected for future risk assessments. Among non-metals, nicotine, and 4-methylnitrosamino-1-(3-pyridyl)-1-butanone (NNK) were shortlisted, as they are classified as persistent and toxic. Further, N-nitrosonornicotine (NNN), with a low HC50 value for chronic aquatic toxicity, had high aquatic toxicity concern and is selected.

Conclusions

The presence of multiple hazardous compounds in waterpipe wastewater highlights the importance of awareness on the proper disposal of waterpipe wastewater in residential and retail settings. Future studies can build on the hazard characterization provided in this study through fate and transport modeling, exposure characterization and risk assessments of waterpipe wastewater chemicals.

Insight into the Potential Mechanisms of Endocrine Disruption by Dietary Phytoestrogens in the Context of the Etiopathogenesis of Endometriosis

Phytoestrogens (PEs) are estrogen-like nonsteroidal compounds derived from plants (e.g., nuts, seeds, fruits, and vegetables) and fungi that are structurally similar to 17β-estradiol. PEs bind to all types of estrogen receptors, including ERα and ERβ receptors, nuclear receptors, and a membrane-bound estrogen receptor known as the G protein-coupled estrogen receptor (GPER). As endocrine-disrupting chemicals (EDCs) with pro- or antiestrogenic properties, PEs can potentially disrupt the hormonal regulation of homeostasis, resulting in developmental and reproductive abnormalities. However, a lack of PEs in the diet does not result in the development of deficiency symptoms. To properly assess the benefits and risks associated with the use of a PE-rich diet, it is necessary to distinguish between endocrine disruption (endocrine-mediated adverse effects) and nonspecific effects on the endocrine system. Endometriosis is an estrogen-dependent disease of unknown etiopathogenesis, in which tissue similar to the lining of the uterus (the endometrium) grows outside of the uterus with subsequent complications being manifested as a result of local inflammatory reactions. Endometriosis affects 10-15% of women of reproductive age and is associated with chronic pelvic pain, dysmenorrhea, dyspareunia, and infertility. In this review, the endocrine-disruptive actions of PEs are reviewed in the context of endometriosis to determine whether a PE-rich diet has a positive or negative effect on the risk and course of endometriosis.

Organochlorine pesticides (OCPs) in freshwater resources of Pakistan: A review on occurrence, spatial distribution and associated human health and ecological risk assessment

The extensive use of organochlorine pesticides (OCPs) has resulted in the widespread contamination of different environmental matrices in Pakistan. Freshwater bodies are also prone to OCPs contamination as they receive agricultural and industrial runoff from different sources. In the present study, the data regarding OCPs' fate and distribution in freshwater resources of Pakistan was reviewed and associated risks to human and ecological health were assessed. Among all the OCPs, DDTs were more prevalent with the highest mean concentration of 2290 ng/L observed in River Ravi (Lahore and Sahiwal District). Human health risk assessment showed a higher risk to the children with high Hazard Quotient (HQ) values ranging between 4.1 × 10^-9- 295 for Aldrin. The River Ravi (Lahore and Sahiwal District), the River Sutlej (Kasur & Bahawalpur District), and the River Kabul (Nowshehra District) were categorized as high-risk water bodies based on Hazard Index (HI) and Non-Cancer Risk (CRI) index values > 10. Ecological risk assessment revealed a higher risk posed to invertebrate species from DDT exposure. In summary, this review highlights the occurrence and distribution of OCPs and their associated human health and ecological risks in freshwater bodies of Pakistan and also contributes to signifying the need for proper management and regulation of banned pesticides and future research perspectives.

Early Life Polychlorinated Biphenyl 126 Exposure Disrupts Gut Microbiota and Metabolic Homeostasis in Mice Fed with High-Fat Diet in Adulthood

Evidence supports the potential influence of persistent organic pollutants (POPs) on the pathogenesis and progression of obesity and diabetes. Diet-toxicant interactions appear to be important in diet-induced obesity/diabetes; however, the factors influencing this interaction, especially the early life environmental exposure, are unclear. Herein, we investigated the metabolic effects following early life five-day exposure (24 μg/kg body weight per day) to 3,3′,4,4′,5-pentacholorobiphenyl (PCB 126) at four months after exposure in mice fed with control (CTRL) or high-fat diet (HFD). Activation of aryl hydrocarbon receptor (AHR) signaling as well as higher levels of liver nucleotides were observed at 4 months after PCB 126 exposure in mice, independent of diet status. Inflammatory responses including higher levels of serum cytokines and adipose inflammatory gene expression caused by early life PCB 126 were observed only in HFD-fed mice in adulthood. Notably, early life PCB 126 exposure worsened HFD-induced impaired glucose homeostasis characterized by glucose intolerance and elevated gluconeogenesis and tricarboxylic acid (TCA) cycle flux without worsening the effects of HFD related to adiposity in adulthood. Furthermore, early life PCB 126 exposure resulted in diet-dependent changes in bacterial community structure and function later in life, as indicated by metagenomic and metabolomic analyses. These data contribute to a more comprehensive understanding of the interactions between diet and early life environmental chemical exposure.

Associations between persistent organic pollutants and type 1 diabetes in youth

BACKGROUND

Diabetes affects millions of people worldwide with a continued increase in incidence occurring within the pediatric population. The potential contribution of persistent organic pollutants (POPs) to diabetes in youth remains poorly known, especially regarding type 1 diabetes (T1D), generally the most prevalent form of diabetes in youth.

OBJECTIVES

We investigated the associations between POPs and T1D in youth and studied the impacts of POPs on pancreatic β-cell function and viability in vitro.

METHODS

We used data and plasma samples from the SEARCH for Diabetes in Youth Case Control Study (SEARCH-CC). Participants were categorized as Controls, T1D with normal insulin sensitivity (T1D/IS), and T1D with insulin resistance (T1D/IR). We assessed plasma concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides and estimated the odds of T1D through multivariable logistic regression. In addition, we performed in vitro experiments with the INS-1E pancreatic β-cells. Cells were treated with PCB-153 or p,p'-DDE at environmentally relevant doses. We measured insulin production and secretion and assessed the mRNA expression of key regulators involved in insulin synthesis (Ins1, Ins2, Pdx1, Mafa, Pcsk1/3, and Pcsk2), glucose sensing (Slc2a2 and Gck), and insulin secretion (Abcc8, Kcnj11, Cacna1d, Cacna1b, Stx1a, Snap25, and Sytl4). Finally, we assessed the effects of PCB-153 and p,p'-DDE on β-cell viability.

RESULTS

Among 442 youths, 112 were controls, 182 were classified with T1D/IS and 148 with T1D/IR. The odds ratios (OR) of T1D/IS versus controls were statistically significant for p,p'-DDE (OR 2.0, 95% confidence interval (CI) 1.0, 3.8 and 2.4, 95% CI 1.2, 5.0 for 2nd and 3rd tertiles, respectively), trans-nonachlor (OR 2.5, 95% CI 1.3, 5.0 and OR 2.3, 95% CI 1.1, 5.1 for 2nd and 3rd tertiles, respectively), and PCB-153 (OR 2.3, 95% CI 1.1, 4.6 for 3rd tertile). However, these associations were not observed in participants with T1D/IR. At an experimental level, treatment with p,p'-DDE or PCB-153, at concentrations ranging from 1 × 10^-15 M to 5 × 10^-6 M, impaired the ability of pancreatic β-cells to produce and secrete insulin in response to glucose. These failures were paralleled by impaired Ins1 and Ins2 mRNA expression. In addition, among different targeted genes, PCB-153 significantly reduced Slc2a2 and Gck mRNA expression whereas p,p'-DDE mainly affected Abcc8 and Kcnj11. While treatment with PCB-153 or p,p'-DDE for 2 days did not affect β-cell viability, longer treatment progressively killed the β-cells.

CONCLUSION

These results support a potential role of POPs in T1D etiology and demonstrate a high sensitivity of pancreatic β-cells to POPs.

Dioxin-like polychlorinated biphenyl 126 (PCB126) disrupts gut microbiota-host metabolic dysfunction in mice via aryl hydrocarbon receptor activation

Exposure to environmental pollutants, including dioxin-like pollutants, can cause numerous health issues. A common exposure route to pollutants is through contaminated foods, and thus the gastrointestinal system and gut microbiota are often exposed to high amounts of pollutants. Multiple studies have focused on the imbalance in intestinal microbiota composition caused by dioxin-like pollutants. Here, we examined the effects of polychlorinated biphenyl 126 (PCB126) on the composition and functions of gut microbes through metagenomic sequencing, and explored the correlations between microflora dysbiosis and aryl hydrocarbon receptor (AHR) signaling. Adult male wild-type and Ahr^-/- mice with a C57BL/6 background were weekly exposed to 50 μg/kg body weight of PCB126 for 8 weeks. Results showed that PCB126 had the opposite effect on gut microbiota composition and diversity in the wild-type and Ahr^-/- mice. Functional prediction found that PCB126 exposure mainly altered carbon metabolism and signal regulatory pathways in wild-type mice but impacted DNA replication and lipopolysaccharide biosynthesis in Ahr^-/- mice. In wild-type mice, PCB126 exposure induced liver injury, decreased serum lipid content, and delayed gastrointestinal motility, which were significantly correlated to several specific bacterial taxa, such as Helicobacter. Following AHR knockout, however, the holistic effects of PCB126 on the host were lessened or abolished. These results suggest that PCB126 may disrupt host metabolism and gut microbiota dynamics via AHR activation. Overall, our findings provide new insight into the complex interactions between host metabolism and gut microbiota, which may contribute to grouped assessment of environmental pollutants in the future.

Prenatal exposure to persistent organic pollutants as a risk factor of offspring metabolic syndrome development during childhood

Persistent Organic Pollutants (POPs) are exogenous, artificially made chemicals that can disrupt the biological system of individuals and animals. POPs encompass a variety of chemicals including, dioxins, organochlorines (OCs), polychlorinated biphenyl (PCBs), and perfluoroalkyl substances (PFASs) that contain a long half-life and highly resistant to biodegradation. These environmental pollutants accumulate over time in adipose tissues of living organisms and alter various insulin function-related genes. Childhood Metabolic Syndrome (MetS) consists of multiple cardiovascular risk factors, insulin function being one of them. Over the years, the incidence of the syndrome has increased dramatically. It is imperative to explore the role of persistent organic pollutants in the development of Childhood Metabolic Syndrome. Some epidemiological studies have reported an association between prenatal exposure to POPs and offspring MetS development throughout childhood. These findings have been replicated in animal studies in which these pollutants exercise negative health outcomes such as obesity and increased waist circumference. This review discusses the role of prenatal exposure to POPs among offspring who develop MetS in childhood, the latest research on the MetS concept, epidemiological and experimental findings on MetS, and the POPs modes of action. This literature review identified consistent research results on this topic. Even though the studies in this review had many strengths, one major weakness was the usage of different combinations of MetS criteria to measure the outcomes. These findings elucidate the urgent need to solidify the pediatric MetS definition. An accurate definition will permit scientists to measure the MetS as a health outcome properly and allow clinicians to diagnose pediatric MetS and provide individualized treatment appropriately.

Iron/titanium oxide-biochar (Fe2TiO5/BC): A versatile adsorbent/photocatalyst for aqueous Cr(VI), Pb2+, F- and methylene blue

This is the first report of the metal Fe-Ti oxide/biochar (Fe₂TiO₅/BC) composite for simultaneous removal of aqueous Pb²⁺, Cr⁶⁺, F^- and methylene blue (MB). Primary Fe₂TiO₅ nano particles and aggregates were dispersed on a high surface area Douglas fir BC (∼700 m²/g) by a simple chemical co-precipitation method using FeCl₃ and TiO(acac)₂ salts treated by base and heated to 80 °C. This was followed by calcination at 500 °C. This method previously was used without BC to make the neat mixed oxide Fe₂TiO₅, exhibiting a lower energy band gap than TiO₂. Adsorption of Cr(VI), Pb(II), fluoride, and MB on Fe₂TiO₅/BC was studied as a function of pH, equilibrium time, initial adsorbate concentration, and temperature. Adsorption isotherm studies were conducted at 5, 25, and 45 ℃ and kinetics for all four adsorbates followed the pseudo second order model. Maximum Langmuir adsorption capacities for Pb²⁺, Cr⁶⁺, F^- and MB at their initial pH values were 141 (pH 2), 200 (pH 5), 36 (pH 6) and 229 (pH 6) mg/g at 45 ℃ and 114, 180, 26 and 210 mg/g at 25 ℃, respectively. MB was removed from the water on Fe₂TiO₅/BC by synergistic adsorption and photocatalytic degradation at pH 3 and 6 under UV (365 nm) light irradiation. Cr⁶⁺, Pb²⁺, F^-, and MB each exhibited excellent removal capacities in the presence of eight different competitive ions in simulated water samples. The removal mechanisms on Fe₂TiO₅/BC and various competitive ion interactions were proposed. Some iron ion leaching at pH 3 catalyzed Photo-Fenton destruction of MB. Fe₂TiO₅, BC, and Fe₂TiO₅/BC bandgaps were studied to help understand photocatalysis of MB and to advance supported metal oxide photodegradation using smaller energy band gaps than the larger bandgap of TiO₂ for water treatment. A long range goal is to photocatalytically destroy some sorbates with adsorbents to avoid the need for regeneration steps.

The state of persistent organic pollutants in South African estuaries: A review of environmental exposure and sources

The long-term health of many South African estuaries is impacted by pollutants entering these systems through industrial and agricultural runoff, sewage outfalls, contaminated storm water drainage, flows from informal settlements, and plastic materials in marine debris. Uncontrolled inputs combined with poor environmental management often result in elevated levels of persistent organic pollutants (POPs) in affected estuaries. Data on POPs research from 1960 to 2020 were analysed in terms of their sources, environmental investigations, and health implications. The outcome showed polychlorinated biphenyls (PCBs) and per- and poly-fluoroalkyl sulphonates (PFASs) to exceed the US EPA health advisory levels for drinking water. Concentration of organochlorine pesticides (OCPs) in water were below the WHO limits, while those in fish tissues from most estuaries were found to be below the US FDA limits. Although environmental compartments in some estuaries (e.g. Rooiels and uMngeni estuaries) seem to be less contaminated relative to other marine systems around the world, many others were polluted and critically modified (e.g. Durban Bay, Swartkops, Sundays, and Buffalo systems). Due to inconsistent monitoring methods coupled with limited data availability, temporal trends were unclear. Of the 290 estuaries in South Africa, 65 were prioritised and recommended for POPs evaluation based on their pollution sources, and a monitoring strategy was defined in terms of sampling. Government policies to curb marine pollution need to be enforced to prevent chronic contamination that leads to water quality deterioration and loss of ecosystem services.

Karrikinolide alleviates BDE-28, heat and Cd stressors in Brassica alboglabra by correlating and modulating biochemical attributes, antioxidative machinery and osmoregulators

In this study, we have evaluated the role of karrikin (KAR¹) against the absorption and translocation of a persistent organic pollutant (POP), 2,4,4'-Tribromodiphenyl ether (BDE-28) in plants, in the presence of two other stressors, cadmium (Cd) and high temperature. Furthermore, it correlates the physiological damages of Brassica alboglabra with the three stresssors separately. The results revealed that the post-germination application of KAR¹ successfully augmented the growth (200%) and pertinent physiochemical parameters of B. alboglabra. KAR¹ hindered air absorption of BDE-28 in plant tissues, and reduced its translocation coefficient (TF). Moreover, BDE-28 was the most negatively correlated (-0.9) stressor with chlorophyll contents, while the maximum mitigation by KAR¹ was also achieved agaist BDE-28. The effect of temperature was more severe on soluble sugars (0.51), antioxidative machinery (-0.43), and osmoregulators (0.24). Cd exhibited a stronger inverse interrelation with the enzymatic antioxidant cascade. Application of KAR¹ mitigated the deleterious effects of Cd and temperature stress on plant physiological parameters along with reduced aero-concentration factor, TF, and metal tolerance index. The phytohormone reduced lipid peroxidation by decreasing synthesis of ROS and persuading its breakdown. The stability of cellular membranes was perhaps due to the commotion of KAR¹ as a growth-promoting phytohormone. In the same way, KAR¹ supplementation augmented the membrane stability index, antioxidant defense factors, and removal efficiency of the pollutants. Consequently, the exogenously applied KAR¹ can efficiently alleviate Cd stress, heat stress, and POP toxicity.

Endocrine disrupting chemicals and metabolic disorders in the liver: What if we also looked at the female side?

Endocrine disrupting chemicals (EDCs) are linked to the worldwide epidemic incidence of metabolic disorders and fatty liver diseases, which affects quality of life and represents a high economic cost to society. Energy homeostasis exhibits strong sexual dimorphic traits, and metabolic organs respond to EDCs depending on sex, such as the liver, which orchestrates both drug elimination and glucose and lipid metabolism. In addition, fatty liver diseases show a strong sexual bias, which in part could also originate from sex differences observed in gut microbiota. The aim of this review is to highlight significant differences in endocrine and metabolic aspects of the liver, between males and females throughout development and into adulthood. It is also to illustrate how the male and female liver differently cope with exposure to various EDCs such as bisphenols, phthalates and persistent organic chemicals in order to draw attention to the need to include both sexes in experimental studies. Interesting data come from analyses of the composition and diversity of the gut microbiota in males exposed to the mentioned EDCs showing significant correlations with hepatic lipid accumulation and metabolic disorders but information on females is lacking or incomplete. As industrialization increases, the list of anthropogenic chemicals to which humans will be exposed will also likely increase. In addition to strengthening existing regulations, encouraging populations to protect themselves and promoting the substitution of harmful chemicals with safe products, innovative strategies based on sex differences in the gut microbiota and in the gut-liver axis could be optimistic outlook.

Stable and ultrasensitive analysis of organic pollutants and heavy metals by dried droplet method with superhydrophobic-induced enrichment

Herein, a dried droplet method (DDM) with superhydrophobic-induced enrichment is reported for stable and ultrasensitive analysis of organic pollutants and heavy metals. A superhydrophobic (SHB) substrate was prepared as an analytical detection platform for the DDM. This SHB substrate was synthesized by sequentially coating polydimethylsiloxane (PDMS) and titanium dioxide nanoparticles (TiO₂ NPs) onto glass substrate surface. In the droplet drying process, the SHB substrate was demonstrated to suppress the coffee ring effect (CRE) and enriched analyte concentration. Combining with Raman spectroscopy for analysis of methylene blue (MB), and with laser-induced breakdown spectroscopy (LIBS) for analysis of chromium (Cr), the results indicated high stability and ultra-sensitivity for organic pollutants and heavy metals detection. Overall, the DDM with superhydrophobic-induced enrichment has big potential in applications requiring stable and ultrasensitive analysis.

Is Technical-Grade Chlordane an Obesogen?

The prevalence of obesity has tripled in recent decades and is now considered an alarming public health problem. In recent years, a group of endocrine disruptors, known as obesogens, have been directly linked to the obesity epidemic. Its etiology is generally associated with a sedentary lifestyle, a high-fat diet and genetic predisposition, but environmental factors, such as obesogens, have also been reported as contributors for this pathology. In brief, obesogens are exogenous chemical compounds that alter metabolic processes and/or energy balance and appetite, thus predisposing to weight gain. Although this theory is still recent, the number of compounds with suspected obesogenic activity has steadily increased over the years, though many of them remain a matter of debate. Technical-grade chlordane is an organochlorine pesticide widely present in the environment, albeit at low concentrations. Highly lipophilic compounds can be metabolized by humans and animals into more toxic and stable compounds that are stored in fat tissue and consequently pose a danger to the human body, including the physiology of adipose tissue, which plays an important role in weight regulation. In addition, technical-grade chlordane is classified as a persistent organic pollutant, a group of chemicals whose epidemiological studies are associated with metabolic disorders, including obesity. Herein, we discuss the emerging roles of obesogens as threats to public health. We particularly discuss the relevance of chlordane persistence in the environment and how its effects on human and animal health provide evidence for its role as an endocrine disruptor with possible obesogenic activity.

Adipose Tissue and Endocrine-Disrupting Chemicals: Does Sex Matter?

Obesity and metabolic-related diseases, among which diabetes, are prominent public health challenges of the 21st century. It is now well acknowledged that pollutants are a part of the equation, especially endocrine-disrupting chemicals (EDCs) that interfere with the hormonal aspect. The aim of the review is to focus on adipose tissue, a central regulator of energy balance and metabolic homeostasis, and to highlight the significant differences in the endocrine and metabolic aspects of adipose tissue between males and females which likely underlie the differences of the response to exposure to EDCs between the sexes. Moreover, the study also presents an overview of several mechanisms of action by which pollutants could cause adipose tissue dysfunction. Indeed, a better understanding of the mechanism by which environmental chemicals target adipose tissue and cause metabolic disturbances, and how these mechanisms interact and sex specificities are essential for developing mitigating and sex-specific strategies against metabolic diseases of chemical origin. In particular, considering that a scenario without pollutant exposure is not a realistic option in our current societies, attenuating the deleterious effects of exposure to pollutants by acting on the gut-adipose tissue axis may constitute a new direction of research.

Catalytic Degradability of p-Nitrophenol Using Ecofriendly Silver Nanoparticles

In an effort to produce non-toxic and economically viable “green” protocols for waste water treatment, researchers are actively involved to develop versatile and effective silver nanoparticles (SNPs) as nano-catalyst from bio-based techniques. Since, p-nitrophenol (PNP) is one of the anthropogenic contaminants, considerable attention has been focused in catalytic degradability of PNP in wastewater treatment by curtailing serious effect on aquatic fauna. Ingestion of contaminants by aquatic organisms will not only affect the aquatic species but is also a potential threat to human health, especially if the toxic contaminants are involved in food chain. In this short report, we provided a comprehensive insight on few remarkable nanocatalysts especially based on SNPs and its biopolymer composites synthesized via ecofriendly “green” route. The beneficiality and catalytic performance of these silver nanocatalysts are concisely documented on standard model degradation reduction of PNP to p-aminophenol (PAP) in the presence of aqueous sodium borohydride. The catalytic degradation of PNP to PAP using SNPs follows pseudo first order kinetics involving six-electrons with lower activation energy. Furthermore, we provided a list of highly effective, recoverable, and economically viable SNPs, which demonstrated its potential as nanocatalysts by focusing its technical impact in the area of water remediation.

Perfluoroalkyl substances (PFASs) and mercury in never-pregnant women of fertile age: association with fish consumption and unfavorable lipid profile

Objectives

To examine concentrations of perfluoroalkyl substances (PFASs) and lifestyle factors that may contribute to higher levels of pollutants in never-pregnant women of fertile age.

Design

Observational cross-sectional study.

Setting

Participants were recruited among employees and students at Haukeland University Hospital and the University of Bergen, Norway.

Participants

Healthy, never-pregnant Norwegian women (n=158) of fertile age (18-39 years).

Outcomes

Concentrations of 20 different PFASs, mercury (Hg), lead, cadmium, total, high-density lipoprotein and low-density lipoprotein (LDL) cholesterol, in addition to self-reported data on dietary intake.

Results

Seven PFASs were detected in more than 95% of the women. Women aged 30-39 years had higher concentrations of sum PFAS compared with younger women. Serum PFASs were significantly intercorrelated (rho: 0.34-0.98, p<0.001) and six of them were significantly correlated to whole blood Hg (rho: 0.21-0.74, p<0.01). Fish consumption was the strongest predictor for most serum PFASs and for whole blood Hg. Fish consumption and serum perfluorooctanesulfonic acid (PFOS) concentrations were both positively associated with serum total and LDL cholesterol, established risk factors for cardiovascular disease.

Conclusions

The majority of Norwegian never-pregnant women of fertile age had a mixture of seven different PFASs and Hg detected in their blood. PFAS concentrations were higher in older women and associated with fish intake. As the mean age of women at first birth is increasing, several factors require further consideration including diet, as this may influence the burden of PFAS to the next generation.

Trial registration number

ClinicalTrials.gov ID: NCT03272022, Unique Protocol ID: 2011/2447, Regional Committee for Medical Research Ethics West (2011/2447), 12 January 2012.

Calcium signaling as a possible mechanism behind increased locomotor response in zebrafish larvae exposed to a human relevant persistent organic pollutant mixture or PFOS

Persistent organic pollutants (POPs) are widespread in the environment and their bioaccumulation can lead to adverse health effects in many organisms. Previously, using zebrafish as a model vertebrate, we found larvae exposed to a mixture of 29 POPs based on average blood levels from the Scandinavian population showed hyperactivity, and identified perfluorooctanesulfonic acid (PFOS) as the driving agent for the behavioral changes. In order to identify possible mechanisms, we exposed zebrafish larvae from 6 to 96 h post fertilization to the same mixture of POPs in two concentrations or a single PFOS exposure (0.55 and 3.83 μM) and performed behavioral tests and transcriptomics analysis. Behavioral alterations of exposed zebrafish larvae included hyperactivity and confirmed previously reported results. Transcriptomics analysis showed upregulation of transcripts related to muscle contraction that is highly regulated by the availability of calcium in the sarcoplasmic reticulum. Ingenuity pathway analysis showed that one of the affected pathways in larvae exposed to the POP mixture and PFOS was calcium signaling via the activation of the ryanodine receptors (RyR). Functional analyses with RyR inhibitors and behavioral outcomes substantiate these findings. Additional pathways affected were related to lipid metabolism in larvae exposed to the lower concentration of PFOS. By using omics technology, we observed that the altered behavioral pattern in exposed zebrafish larvae may be controlled directly by mechanisms affecting muscle function rather than via mechanisms connected to neurotoxicity.

Trophic Magnification of Legacy (PCB, DDT and Hg) and Emerging Pollutants (PFAS) in the Fish Community of a Small Protected Southern Alpine Lake (Lake Mergozzo, Northern Italy)

The biomagnification of mercury, polychlorobiphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs) and perfluoroalkyl acids substances (PFASs) was evaluated in the trophic web of Lake Mergozzo, a small and deep Italian subalpine lake, which has been chosen because it is a protected environment, and discharges into the lake are mostly avoided. Carbon source and relative trophic levels were calculated by using 13C and 15N stable isotopes, respectively, and trophic magnification factors (TMFs) were derived. Zooplankton and thirteen species of fish were collected and analyzed, and the results showed the elevated level of biota contamination from both legacy and emerging pollutants, even if direct discharges were avoided. Concentrations in biota, expressed as sums of compounds, ranged from 0.4 to 60 µg kg−1 wet weight (ww) for PFASs, from 16 to 1.3 104 µg kg−1 lipid content (lw) for DDTs, from 17 to 1.5 104 µg kg−1 lw for PCBs and from 20.0 to 501 µg kg−1 ww for mercury (Hg). TMFs of this deep, cold lake, with a prevalent pelagic trophic chain, were high and clearly indicated fish biomagnification, except for PFAS. The biomagnification capability of PFAS in a fish-only food web was discussed by using the biomagnification of Hg as a benchmark for assessing their bioaccumulation potential.

Appalachian Environmental Health Literacy: Building Knowledge and Skills to Protect Health

Environmental health literacy (EHL) is an emerging, multidisciplinary field that promotes understanding of how environmental exposures can affect human health. After discussing the regional relevance of environmental health knowledge and skills, this article describes three ongoing Appalachian projects that are focused on measuring and building EHL.

Technical-grade chlordane compromises rat Sertoli cells proliferation, viability and metabolic activity

Environmental contaminants are a daily presence in human routine. Multiple studies highlight the obesogenic activity of some chemicals. Moreover, these compounds have been suggested as a cause of male subfertility and/or infertility. Technical-grade chlordane (TGC) is classified as an endocrine-disruptor chemical, while its classification as obesogen is controversial. Herein, we studied the influence of TGC on Sertoli cells (SCs) metabolism. Rat Sertoli cells (rSCs) were cultured without and in the presence of increasing concentrations (1, 10 and 1000 nM) of TGC. The viability, proliferation, metabolic activity and the metabolic profile of rSCs was assessed. Expression of key glycolysis-related enzymes, transporters and biomarkers of oxidative damage were also evaluated. Our results show that exposure to higher concentrations of TGC decreases SCs proliferation and viability, which was accompanied by increased glucose consumption associated with an upregulation of Glut3 levels. As a result, pyruvate/lactate production were enhanced thus increasing the glycolytic flux in cells exposed to 1000 nM TGC, although lactate dehydrogenase expression and activity did not increase. Notably, biomarkers associated with oxidative damage remained unchanged after exposure to TGC. This is the first report showing that TGC alters glucose rSCs metabolism and the nutritional support of spermatogenesis with consequences for male fertility.

Persistent Organic Pollutants in Food: Contamination Sources, Health Effects and Detection Methods

Persistent organic pollutants (POPs) present in foods have been a major concern for food safety due to their persistence and toxic effects. To ensure food safety and protect human health from POPs, it is critical to achieve a better understanding of POP pathways into food and develop strategies to reduce human exposure. POPs could present in food in the raw stages, transferred from the environment or artificially introduced during food preparation steps. Exposure to these pollutants may cause various health problems such as endocrine disruption, cardiovascular diseases, cancers, diabetes, birth defects, and dysfunctional immune and reproductive systems. This review describes potential sources of POP food contamination, analytical approaches to measure POP levels in food and efforts to control food contamination with POPs.

Low-dose PCB126 compromises circadian rhythms associated with disordered glucose and lipid metabolism in mice

It has been documented that 3, 3', 4, 4', 5-pentachlorobiphenyl (PCB126) elicits diverse detrimental effects on human health including metabolic syndrome and non-alcoholic fatty-liver disease (NAFLD), through a wide array of non-carcinogenic mechanisms, which require further detailed investigations. The circadian clock system consists of central clock machinery (located in the suprachiasmatic nucleus in the hypothalamus) and the peripheral clocks (located in nearly all peripheral tissues). Peripheral clocks in the liver play fundamental roles in maintaining liver homeostasis, including the regulation of energy metabolism and the expression of enzymes that fine-tune the absorption and metabolism of xenobiotics. However, the molecular basis of whether PCB126 disrupts liver homeostasis (e.g., glucose and lipid metabolism) by dysregulating the circadian clock system is still unknown. Thus, we performed a set of comprehensive analyses of glucose and lipid metabolism in the liver tissues from low-dose PCB126-treated mice. Our results demonstrated that PCB126 diminished glucose and cholesterol levels in serum and elevated glucose and cholesterol levels in the liver. Moreover, PCB126 compromised PGC1α and PDHE1α, which are the driving force for mitochondrial biogenesis and entry of pyruvate into the tricarboxylic acid (TCA) cycle, respectively, and resulted in the accumulation of glucose, glycogen and pyruvate in the liver after PCB126 exposure. Additionally, PCB126 blocked hepatic cholesterol metabolism and export pathways, leading to an elevated localization of hepatic cholesterol. Mechanistic investigations illustrated that PCB126 greatly altered the expression profile of core clock genes and their target rhythm genes involved in orchestrating glucose and cholesterol metabolism. Together, our results demonstrated that a close correlation between PCB126-disturbed glucose and lipid metabolism and disordered physiological oscillation of circadian genes.

A screening-level approach to quantifying risk from glacial release of organochlorine pollutants in the Alaskan Arctic

Widespread distribution of atmospherically mobilized organochlorine pollutants (OCPs) has been documented throughout the Arctic. A fraction of these OCPs have become entrained in glacial ice, and during melting, they can be released into downstream reservoirs. Though this remobilization is known, an assessment of risk from glacial meltwater to collocated human communities in the Arctic, including Alaska, had not been accomplished. Here, we use a screening-level risk assessment model for glacial watersheds, based on US Environmental Protection Agency (EPA) methodology, which we apply to the glaciated Jarvis Creek watershed of interior Alaska. Model results indicate that even with low levels of OCPs in glacial meltwater, high fish consumption by subsistence communities in the area increases the risk of cancer and hazard impacts above acceptable limits. Though this model is specific to one watershed, our results imply that further investigation of an increasing OCP signal in glacial meltwater and fish throughout the North American Arctic is warranted.

Evaluation of selected polychlorinated biphenyls (PCBs) congeners and dichlorodiphenyltrichloroethane (DDT) in fresh root and leafy vegetables using GC-MS

Persistent organic pollutants (POPs) are dangerous and toxic pollutants that may cause adverse effects on human and animal health, including death. POPs such as polychlorinated biphenyls (PCBs) and pesticides are subtly released into the environment from industrial and agricultural use. Global circulation is due to their trans-boundary transport capacity, contingent on aerodynamic and hydrological properties. Plants have capacity to take-up POPs, and these bio-magnify along heterotrophic transfer pathways. In this study, levels of selected 6-PCB congeners and 3- DDTs in some leaf and root vegetables were investigated. Leaf and root vegetables were collected from different horticultural farms areas in Cape Town. The 6-PCBs and 3-DDTs were recovered from the samples using solid phase extraction(SPE), followed by GC-MS analysis. The ΣPCBs and ΣDDT (on-whole basis), were ranged: 90.9–234 ng/g and 38.9–66.1 ng/g respectively. The 3-PCBs and 6-DDTs levels were slightly higher in leaf vegetables compared to root vegetables. The detection of PCBs and DDTs in the vegetables suggest the probable use of PCBs containing pesticides. Although the observed concentrations were below the WHO maximum residue limits, consumption of such contaminated leaf and root vegetables portend a health risk.

Exposure to persistent organic pollutants: impact on women's health

This literature review focuses on the causal relationship between persistent organic pollutants (POPs) exposure and women's health disorders, particularly cancer, cardio-metabolic events and reproductive health. Progressive industrialization has resulted in the production of a multitude of chemicals that are released into the environment on a daily basis. Environmental chemicals or pollutants are not only hazardous to our ecosystem but also lead to various health problems that affect the human population worldwide irrespective of gender, race or age. However, most environmental health studies that have been conducted, until recently, were exclusively biased with regard to sex and gender, beginning with exposure studies that were reported mostly in male, occupational workers and animal studies being carried out mostly in male rodent models. Health-related issues pertaining to women of all age groups have not been studied thoroughly and rather disregarded in most aspects of basic health science research and it is therefore pertinent that we address these limitations in environmental health. The review also addresses studies looking at the associations between health outcomes and exposures to POPs, particularly, polychlorinated biphenyls (PCBs), dioxins and pesticides, reported in cohort studies while accounting for gender differences. Considering that current levels of POPs in women can also impact future generations, informative guidelines related to dietary patterns and exposure history are needed for women of reproductive age. Additionally, occupational cohorts of highly exposed women worldwide, such as women working in manufacturing plants and female pesticide applicators are required to gather more information on population susceptibility and disease pathology.

PCB126 Inhibits the Activation of AMPK-CREB Signal Transduction Required for Energy Sensing in Liver

3,3',4,4',5-pentachlorobiphenyl (PCB126), a dioxin-like PCB, elicits toxicity through a wide array of noncarcinogenic effects, including metabolic syndrome, wasting, and nonalcoholic fatty-liver disease. Previously, we reported decreases in the transcription of several enzymes involved in gluconeogenesis, before the early onset of lipid accumulation. Hence, this study was aimed at understanding the impact of resultant decreases gluconeogenic enzymes on growth, weight, and metabolism in the liver, upon extended exposure. Male Sprague Dawley rats (75-100 g), fed a defined AIN-93G diet, were injected (ip) with single dose of soy oil (5 ml/kg body weight; n = 14) or PCB126 (5 µmol/kg; n = 15), 28 days, prior euthanasia. A subset of rats from each group were fasted for 12 h (vehicle [n = 6] and PCB126 [n = 4]). Rats only showed significant weight loss between days 14 and 28 (p < .05) and some mortality (p = .0413). As in our previous studies, the expression levels of enzymes involved in gluconeogenesis (Pepck-c, G6Pase, Sds, Pc, and Ldh-A) and glycogenolysis (Pygl) were strongly downregulated. The decreased expression of these enzymes in PCB126-treated rats after a 12 h fast decreased hepatic glucose production from glycogen and gluconeogenic substrates, exacerbating the hypoglycemia. Additionally, PCB126 caused hepatic steatosis and decreased the expression of the transcription factor Pparα and its targets, necessary for fatty-acid oxidation. The observed metabolic disruption across multiple branches of fasting metabolism resulted from inhibition in the activation of enzyme AMPK and transcription factor CREB signaling, necessary for "sensing" energy-deprivation and the induction of enzymes that respond to the PCB126 triggered fuel crisis in liver.

A rapid and reagent-free bioassay for the detection of dioxin-like compounds and other aryl hydrocarbon receptor (AhR) agonists using autobioluminescent yeast

An autonomously bioluminescent Saccharomyces cerevisiae BLYAhS bioreporter was developed in this study for the simple and rapid detection of dioxin-like compounds (DLCs) and aryl hydrocarbon receptor (AhR) agonists. This recombinant yeast reporter was based on a synthetic bacterial luciferase reporter gene cassette (lux) that can produce the luciferase as well as the enzymes capable of self-synthesizing the requisite substrates for bioluminescent production from endogenous cellular metabolites. As a result, bioluminescent signal production is generated continuously and autonomously without cell lysis or exogenous reagent addition. By linking the expression of the autobioluminescent lux reporter cassette to AhR activation via the use of a dioxin-responsive promoter, the S. cerevisiae BLYAhS bioreporter emitted a bioluminescent signal in response to DLC exposure in a dose-responsive manner. The model dioxin, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), could be detected within 4 h with a half maximal effective concentration (EC₅₀) of ~ 8.1 nM and a lower detection limit of 500 pM. The autobioluminescent response of BLYAhS to other AhR agonists, including 2,3,7,8-tetrachlorodibenzofuran (TCDF), polychlorinated bisphenyl congener 126 (PCB-126) and 169 (PCB-169), 1,2,3,6,7,8-hexachlorodibenzo-p-dioxin (HxCDD), 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (HpCDD), benzo[a]pyrene (BaP), and β-naphthoflavone (bNF), were also characterized in this study. The non-destructive and reagent-free nature of the BLYAhS reporter assay facilitated near-continuous, automated signal acquisition without additional hands-on effort and cost, providing a simple and cost-effective method for rapid DLC detection.

Low-dose pollutant mixture triggers metabolic disturbances in female mice leading to common and specific features as compared to a high-fat diet

Environmental pollutants are potential etiologic factors of obesity and diabetes that reach epidemic proportions worldwide. However, it is important to determine if pollutants could exert metabolic defects without directly inducing obesity. The metabolic disturbances triggered in nonobese mice lifelong exposed to a mixture of low-dose pollutants (2,3,7,8-tetrachlorodibenzo-p-dioxine, polychlorinated biphenyl 153, diethylhexyl-phthalate, and bisphenol A) were compared with changes provoked by a high-fat high-sucrose (HFHS) diet not containing the pollutant mixture. Interestingly, females exposed to pollutants exhibited modifications in lipid homeostasis including a significant increase of hepatic triglycerides but also distinct features from those observed in diet-induced obese mice. For example, they did not gain weight nor was glucose tolerance impacted. To get more insight, a transcriptomic analysis was performed in liver for comparison. We observed that in addition to the xenobiotic/drug metabolism pathway, analysis of the hepatic signature illustrated that the steroid/cholesterol, fatty acid/lipid and circadian clock metabolic pathways were targeted in response to pollutants as observed in the diet-induced obese mice. However, the specific sets of dysregulated annotated genes (>1300) did not overlap more than 40% between both challenges with some genes specifically altered only in response to pollutant exposure. Collectively, results show that pollutants and HFHS affect common metabolic pathways, but by different, albeit overlapping, mechanisms. This is highly relevant for understanding the synergistic effects between pollutants and the obesogenic diet reported in the literature.

Marine-Derived Biocatalysts: Importance, Accessing, and Application in Aromatic Pollutant Bioremediation

The aim of the present review is to highlight the potential use of marine biocatalysts (whole cells or enzymes) as an alternative bioprocess for the degradation of aromatic pollutants. Firstly, information about the characteristics of the still underexplored marine environment and the available scientific tools used to access novel marine-derived biocatalysts is provided. Marine-derived enzymes, such as dioxygenases and dehalogenases, and the involved catalytic mechanisms for the degradation of aromatic and halogenated compounds, are presented, with the purpose of underpinning their potential use in bioremediation. Emphasis is given on persistent organic pollutants (POPs) that are organic compounds with significant impact on health and environment due to their resistance in degradation. POPs bioaccumulate mainly in the fatty tissue of living organisms, therefore current efforts are mostly focused on the restriction of their use and production, since their removal is still unclear. A brief description of the guidelines and criteria that render a pollutant POP is given, as well as their potential biodegradation by marine microorganisms by surveying recent developments in this rather unexplored field.

Obesity, Persistent Organic Pollutants and Related Health Problems

The present review aims to delve into persistent organic pollutants (POPs) , as xenobiotics, in correlation to human health. POPs exhibit a group of common characteristics, including lipophilicity, persistence to decomposition and bioaccumulation in tissues. POPs have been thoroughly studied by former researchers, as they offer a particular interest in the elucidation of metabolic, endocrine and immune perturbation caused by their synergy with intracellular mechanisms. Herein particular focus is attributed to the relationship of POPs with obesity provocation. Obesity nowadays receives epidemic dimensions, as its prevalence elevates in an exponential degree. POPs-induced obesity rotates around interfering in metabolic and endocrinal procedures and interacting with peroxisome-proliferator and retinoic receptors. Moreover, polymorphisms in CYP gene families exert a negative result, as they incapacitate detoxification of POPs. Obesity could be deemed as a multidimensional condition, as various factors interact to lead to an obesogenic result. Therefore, concomitant disorders may occur, from mild to lethal, and get intensified due to POPs exposure. POPs exact function mechanisms remain rather enigmatic, thus further investigation should be prospectively performed, for a more lucid picture of this issue, and, consequently for the establishment of alternative solutions.

Persistent Organic Pollutants and Concern Over the Link with Insulin Resistance Related Metabolic Diseases

Persistent organic pollutants (POPs) are mostly halogenated compounds tending to persist in the environment, enter into the food chain, and accumulate in fat mass of mammals due to their high lipophilicity. They include some organochlorine pesticides, polychlorinated biphenyls, brominated flame retardants and polycyclic aromatic hydrocarbons. Some of these chemicals were widely used in the past so that their residues can be detected in the human body, though their usage has been banned for years. POPs have been shown to perturb the health of biological systems in different ways evidenced by carcinogenicity and disrupting effects on endocrine, immune, and reproductive systems. There are many epidemiologic and experimental studies on the association of exposure to POPs with insulin resistance and related metabolic disorders like obesity, diabetes, and metabolic syndrome. Inflammation as a known mechanism accompanying insulin resistance has also been shown to arise in insulin target tissues exposed to POPs. This review addresses the breast milk concentration of POPs in different regions of the world, synthesizes the current information on the association of POPs with insulin resistance related metabolic disorders, and discusses the inflammation as an involved mechanism. Considering high prevalence of insulin resistance related metabolic diseases and their relation with POPs, much need is felt regarding international and regional programs to not only limit their production and usage but eliminate these persistent pollutants from the environment.

PCB126-Induced Disruption in Gluconeogenesis and Fatty Acid Oxidation Precedes Fatty Liver in Male Rats

3,3',4,4',5-Pentachlorobiphenyl (PCB126), a dioxin-like polychlorinated biphenyl (PCB) and a potent aryl hydrocarbon receptor (AhR) agonist, is implicated in the disruption of both carbohydrate and lipid metabolism which ultimately leads to wasting disorders, metabolic disease, and nonalcoholic fatty liver disease. However, the mechanisms are unclear. Because liver is the target organ for PCB toxicity and responsible for metabolic homeostasis, we hypothesized that early disruption of glucose and lipid homeostasis contributes to later manifestations such as hepatic steatosis. To test this hypothesis, groups of male Sprague Dawley rats, fed on AIN-93G diet, were injected (intraperitoneal.) with a single bolus of PCB126 (5 µmol/kg) at various time intervals between 9 h and 12 days prior to euthanasia. An early decrease in serum glucose and a gradual decrease in serum triglycerides were observed over time. Liver lipid accumulation was most severe at 6 and 12 days of exposure. Transcript levels of cytosolic phosphoenol-pyruvate carboxykinase (Pepck-c/Pck1) and glucose transporter (Glut2/Slc2a2) involved in gluconeogenesis and hepatic glucose transport were time-dependently downregulated between 9 h and 12 days of PCB126 exposure. Additionally, transcript levels of Pparα, and its targets acyl-CoA oxidase (Acox1) and hydroxy-3-methylglutaryl-CoA synthase 2 (Hmgcs2), were also downregulated, indicating changes in peroxisomal fatty acid oxidation and ketogenesis. In a separate animal study, we found that the measured changes in the transcript levels of Pepck-c, Glut2, Pparα, Acox1, and Hmgcs2 were also dose dependent. Furthermore, PCB126-induced effects on Pepck-c were demonstrated to be AhR dependent in rat H4IIE hepatocytes. These results indicate that PCB126-induced wasting and steatosis are preceded initially by (1) decreased serum glucose caused by decreased hepatic glucose production, followed by (2) decreased peroxisomal fatty acid oxidation.

Effects of Anthropogenic Pollution on the Oxidative Phosphorylation Pathway of Hepatocytes from Natural Populations of Fundulus heteroclitus

Persistent organic pollutants (POPs), including polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), potentially target mitochondria and cause toxicity. We compared the effects of POPs on mitochondrial respiration by measuring oxidative phosphorylation (OxPhos) metabolism in hepatocytes isolated from lab-depurated Fundulus heteroclitus from a Superfund site contaminated with PAHs (Elizabeth River VA, USA) relative to OxPhos metabolism in individuals from a relatively clean, reference population (King's Creek VA, USA). In individuals from the polluted Elizabeth River population, OxPhos metabolism displayed lower LEAK and lower activities in complex III, complex IV, and E State, but higher activity in complex I compared to individuals from the reference King's Creek population. To test the supposition that these differences were due to or related to the chronic PAH contamination history of the Elizabeth River population, we compared the OxPhos functions of undosed individuals from the polluted and reference populations to individuals from these populations dosed with a PAH {benzo [α] pyrene (BaP)} or a PCB {PCB126 (3,3',4,4',5-pentachlorobiphenyl)}, respectively. Exposure to PAH or PCB affected OxPhos in the reference King's Creek population but had no detectable effects on the polluted Elizabeth River population. Thus, PAH exposure significantly increased LEAK, and exposure to PCB126 significantly decreased State 3, E state and complex I activity in the reference King's Creek population. These data strongly implicate an evolved tolerance in the Elizabeth River fish where dosed fish are not affected by PAH exposure and undosed fish show decreased LEAK and increased State 3 and E state.

Fat, epigenome and pancreatic diseases. Interplay and common pathways from a toxic and obesogenic environment

The worldwide obesity epidemic is paralleled by a rise in the incidence of pancreatic disorders ranging from "fatty" pancreas to pancreatitis and cancer. Body fat accumulation and pancreatic dysfunctions have common pathways, mainly acting through insulin resistance and low-grade inflammation, frequently mediated by the epigenome. These mechanisms are affected by lifestyle and by the toxic effects of fat and pollutants. An early origin is common, starting in pediatric age or during the fetal life in response to nutritional factors, endocrine disruptor chemicals (EDCs) or parental exposure to toxics. A "fatty pancreas" is frequent in obese and is able to induce pancreatic damage. The fat is a target of EDCs and of the cytotoxic/mutagenic effects of heavy metals, and is the site of bioaccumulation of lipophilic and persistent pollutants related with insulin resistance and able to promote pancreatic cancer. Increased Body Mass Index (BMI) can act as independent risk factor for a more severe course of acute pancreatitis and obesity is also a well-known risk factor for pancreatic cancer, that is related with BMI, insulin resistance, and duration of exposure to the toxic effects of fat and/or of environmental pollutants. All these mechanisms involve gene-environment interactions through epigenetic factors, and might be manipulated by primary prevention measures. Further studies are needed, pointing to better assess the interplays of modifiable factors on both obesity and pancreatic diseases, and to verify the efficacy of primary prevention strategies involving lifestyle and environmental exposure to toxics.

Dichlorodiphenyltrichloroethane exposure induces the growth of hepatocellular carcinoma via Wnt/β-catenin pathway

Dichlorodiphenyltrichloroethane (DDT) is a persistent organic pollutant, involved in the progression of many cancers, including liver cancer. However, the underlying mechanism(s) of DDT, especially how low doses DDT cause liver cancer, is poorly understood. In this study, we evaluated the impact of p,p'-DDT on the growth of hepatocellular carcinoma using both in vitro and in vivo models. The present data indicated that the proliferation of HepG2 cells was strikingly promoted after exposed to p,p'-DDT for 4 days. In addition, reactive oxygen species (ROS) content was significantly elevated, accompanied with inhibitions of γ-glutamylcysteine synthetase (γ-GCS) and superoxide dismutase (SOD) activities. Interestingly, the levels of β-catenin and its downstream target genes (c-Myc and CyclinD1) were significantly up-regulated, and co-treatment of NAC, the ROS inhibitor, inhibited these over-expressed proteins. Moreover, the p,p'-DDT-stimulated proliferation of HepG2 cells could be reversed after NAC or β-catenin siRNA co-treatment. Likewise, p,p'-DDT treatment increased the growth of tumor in nude mice, stimulated oxidative stress and Wnt/β-catenin pathway. Our study indicates that low doses p,p'-DDT exposure promote the growth of hepatocellular carcinoma via Wnt/β-catenin pathway which is activated by oxidative stress. The finding suggests an association between low dose DDT exposure and liver cancer growth.

High incidence of prostate cancer metastasis in Afro-Brazilian men with low educational levels: a retrospective observational study

BACKGROUND

This study investigated factors related to ethnicity and educational level, their correlation with tumor stage at the time of diagnosis, and their influence on treatment outcomes in patients with prostate cancer.

METHODS

In this retrospective observational study, we analyzed the medical records of 1,349 male patients treated for prostatic adenocarcinoma. We collected information about sociodemographic variables, including educational level and self-reported skin color. We also classified the disease according whether it was to more likely to present with metastasis and measured the tumor response to treatment.

RESULTS

Less-educated (<8 years of education) individuals were 4.8 times more likely to develop metastasis than those with more education (>11 years of education; p < 0.001). Similarly, patients with a self-reported black skin color had a 300% increased risk of metastasis at diagnosis (p = 0.001). Distant metastasis was independently correlated with worse outcomes, such that individuals with distant metastasis were 10 times more likely to die than were those without distant metastasis.

CONCLUSIONS

Patients with self-reported black skin color and <8 years of education were more likely to display advanced disease at the time of diagnosis compared with their counterparts. Only the presence of metastasis was independently associated with mortality or progressive disease.

Evaluation of the INS-1 832/13 cell line as a beta-cell based screening system to assess pollutant effects on beta-cell function

Environmental pollutants have recently emerged as potential risk factors for metabolic diseases, urging systematic investigation of pollutant effects on metabolic disease processes. To enable risk assessment of these so-called metabolic disruptors the use of stable, robust and well-defined cell based screening systems has recently been encouraged. Since beta-cell (dys)functionality is central in diabetes pathophysiology, the need to develop beta-cell based pollutant screening systems is evident. In this context, the present research evaluated the strengths and weaknesses of the INS-1 832/13 pancreatic beta-cell line as diabetogenic pollutant screening system with a focus on beta-cell function. After optimization of exposure conditions, positive (exendin-4, glibenclamide) and negative (diazoxide) control compounds for acute insulin secretion responses were tested and those with the most profound effects were selected to allow potency estimations and ranking of pollutants. This was followed by a first explorative screening of acute bisphenol A and bis(2-ethylhexyl)phthalate effects. The same approach was applied for chronic exposures, focusing primarily on evaluation of acknowledged chronic stimulators (diazoxide, T0901317, exendin-4) or inhibitors (glibenclamide) of insulin secretion responses to select the most responsive ones for use as control compounds in a chronic pollutant testing framework. Our results showed that INS-1 832/13 cells responded conform previous observations regarding acute effects of control compounds on insulin secretion, while bisphenol A and bis(2-ethylhexyl)phthalate had limited acute effects. Furthermore, chronic exposure to known beta-cell reactive compounds resulted in deviating insulin secretion and insulin content profiles compared to previous reports. In conclusion, this INS-1 subclone appears to lack certain characteristics needed to respond appropriately to acute pollutant exposure or long term exposure to known beta-cell reactive compounds and thus seems to be, in our setting, inadequate as a diabetogenic pollutant screening system.

Metabolic impacts of high dietary exposure to persistent organic pollutants in mice

Persistent organic pollutants (POPs) have been linked to metabolic diseases. Yet, the effects of high exposure to dietary POPs remain unclear. We therefore investigated whether elevated exposure to POPs provided by whale meat supplementation could contribute to insulin resistance. C57BL/6J mice were fed control (C) or very high-fat diet (VHF) containing low or high levels of POPs (VHF(+POPs)) for eight weeks. To elevate the dietary concentrations of POPs, casein was replaced by whale meat containing high levels of pollutants. Feeding VHF(+POPs) induced high POP accumulation in the adipose tissue of mice. However, compared with VHF-fed mice, animals fed VHF(+POPs) had improved insulin sensitivity and glucose tolerance, and reduced body weight. Levels of ectopic fat in skeletal muscles and liver were reduced in mice fed VHF(+POPs). These mice also gained less adipose tissue and had a tendency to reduced energy intake. In pair-feeding experiments, improved insulin action and reduced body weight gain were still observed in VHF(+POPs) compared to VHF pair-fed mice. We concluded that mice fed VHF contaminated with POPs derived from whale meat remain sensitive to insulin and glucose tolerant despite significant body burden of POPs. This indicates complex interactions between organic pollutants and nutrition in the development of metabolic disorders.