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Selenium prevent cadmium-induced hepatotoxicity through modulation of endoplasmic reticulum-resident selenoproteins and attenuation of endoplasmic reticulum stress Full text
2020
Zhang, Cong | Ge, Jing | Lv, Meiwei | Zhang, Qi | Talukder, Milton | Li, Jin-Long
Cadmium (Cd), a heavy metal contaminant, exists in humans and animals throughout life and closely associate with severe hepatotoxicity. Selenium (Se) has been recognized as an effective chemo-protectant of Cd, but the underlying mechanisms remain unclear. The objective of the present study is to illustrate the antagonistic effect of Se against Cd-induced hepatotoxicity. Primary hepatocytes were cultured in the presence of 5 μM Cd, 1 μM Se and the mixture of 1 μM Se and 5 μM Cd for 24 h. Cell viability and morphology, antioxidant status, endoplasmic reticulum (ER) stress response and selenotranscriptome were assessed. It was observed that Se treatment dramatically alleviated Cd-induced hepatocytes death and morphological change. Simultaneously, Se mitigated Cd-induced oxidative stress by reducing ROS production, increasing reduced glutathione (GSH) level and increasing selenoenzyme (glutathione peroxidase, GPX) activity. Cd induced hepatotoxicity via disordering ER-resident selenoproteins transcription and triggering ER stress and unfolded protein response. Supplementary Se evidently relieved hepatocytes injury via modulating ER-resident selenoproteins transcription to inhibit ER stress. Collectively, our findings showed a potential protection of Se against Cd-induced hepatotoxicity via suppressing ER stress response.
Show more [+] Less [-]Cropland acidification increases risk of yield losses and food insecurity in China Full text
2020
Zhu, Qichao | Liu, Xuejun | Hao, Tianxiang | Zeng, Mufan | Shen, Jianbo | Zhang, Fusuo | de Vries, Wim
Distinct cropland acidification has been reported in China due to nitrogen (N) fertilizer overuse. However, the impacts on food production and thereby on food security are largely unknown. Yield losses in the period 1980–2050 were therefore assessed by simulating soil pH changes combined with derived pH-yield relationships for wheat, maize and rice. If the N fertilizer input continues to increase at 1% annually, the predicted average soil pH decline is about one unit and relative yield losses are expected to increase from approximately 4%–24% during 2010–2050. If the N fertilizer increase stops in 2020 (N2020), the expected losses are approximately 16% in 2050, which is comparable to a scenario of 100% crop residue return (100%RR). However, if 30% of the N fertilizer is replaced by manure N (30%MR), the losses reduce to near 5% in 2050. Soil acidification was predicted to reverse and expected losses are only 2.5% in 2050 in a combined scenario of N2020, 100%RR and 30%MR. Our results illustrate the potential food insecurity induced by cropland acidification and address the necessity of mitigation.
Show more [+] Less [-]Effects of polystyrene diet on Tenebrio molitor larval growth, development and survival: Dynamic Energy Budget (DEB) model analysis Full text
2020
Matyja, Konrad | Rybak, Justyna | Hanus-Lorenz, Beata | Wrobel, Magdalena | Rutkowski, Radosław
The presence of polystyrene (PS) waste increases constantly. Styrofoam, the most popular form of PS, is one of the major plastic pollutants in the environment. An efficient and environmentally friendly method of PS recycling is still needed. The biodegradation of PS by insects has been presented by researchers as a promising alternative to chemical, mechanical and thermal methods. The main aim of this study was to assess the survival, growth, and development of yellow mealworms (the larvae of Tenebrio molitor) fed with PS to determine if the insects are able to use PS as a source of mass and energy. The Dynamic Energy Budget (DEB) model was used to analyze the effects of food type on the growth trajectory and metabolism of tested organisms. We investigated five possible modes of influence of PS diet on DEB model parameters including a decrease of food availability, an increase in somatic maintenance power, an increase in costs for structure, allocation of energy, and a decrease in somatic maintenance power. Our results show that changes in the development of larvae fed with PS are mainly caused by a decrease in reserves density and reaction of the organism to the insufficient food supply. The inability or difficulty in completing the life cycle of T. molitor larvae fed with PS raises doubts about the use of mealworms as an effective technology for utilizing polystyrene.
Show more [+] Less [-]Nitrous oxide emissions in response to straw incorporation is regulated by historical fertilization Full text
2020
Wu, Lei | Hu, Ronggui | Tang, Shuirong | Shaaban, Muhammad | Zhang, Wenju | Shen, Huaping | Xu, Minggang
The incorporation of crop straw with fertilization is beneficial for soil carbon sequestration and cropland fertility improvement. Yet, relatively little is known about how fertilization regulates the emissions of the greenhouse gas nitrous oxide (N₂O) in response to straw incorporation, particularly in soils subjected to long-term fertilization regimes. Herein, the arable soil subjected to a 31-year history of five inorganic or organic fertilizer regimes (unfertilized; chemical fertilizer application, NPK; 200% NPK application, 2 × NPK; manure application, M; NPK plus manure application, NPKM) was incubated with and without rice straw to evaluate how historical fertilization influences the impact of straw addition on N₂O emissions. The results showed that compared to the unfertilized treatment, historical fertilization strongly increased N₂O emissions by 0.48- to 34-fold, resulting from increased contents of hot water-extracted organic carbon (HWEOC), NO₃⁻, and available phosphorus (Olsen-P). Straw addition had little impact on N₂O emission from the unfertilized and NPK treatments, primarily due to Olsen-P limitation. In contrast, straw addition increased N₂O emissions by 102–316% from the 2 × NPK, M, and NPKM treatments as compared to the corresponding straw-unamended treatments. These results indicated that N₂O emissions in response to straw addition were largely regulated by historical fertilization. The N₂O emissions were closely associated with the depletion of NO₃⁻ and decoupled from change in NH₄⁺ content, suggesting that NO₃⁻ was the main substrate for N₂O production upon straw addition. The stoichiometric ratios of HWEOC to mineral N and mineral N to Olsen-P were key factors affecting N₂O emissions, underscoring the importance of resource stoichiometry in regulating N₂O emissions. In conclusion, historical fertilization largely regulated the impacts of crop straw incorporation on N₂O emissions via shifts in NO₃⁻ depletion and the stoichiometry of HWEOC, mineral N, and Olsen-P.
Show more [+] Less [-]Antithrombotic medication and endovascular interventions associated with short-term exposure to particulate air pollution: A nationwide case-crossover study Full text
2020
Scheers, Hans | Nawrot, Tim S. | Nemery, Benoit | De Troeyer, Katrien | Callens, Michael | De Smet, Frank | Nieuwenhuyse, An van | Casas, Lidia
Short-term exposure to air pollution has pro-thrombotic effects and triggers thrombo-embolic events such as myocardial infarction or stroke in adults. This study evaluates the association between short-term variation in air pollution and treatments for acute thrombo-embolic events among the whole Belgian population. In a bidirectional time-stratified case-crossover design, we included 227,861 events treated with endovascular intervention and 74,942 with antithrombotic enzymes that were reimbursed by the Belgian Social Security between January 1st, 2009 and December 31st, 2013. We compared the concentrations of particulate matter (PM) air pollution (PM₁₀ and PM₂.₅), as estimated at the municipality level on the day of the event (lag 0) and two days earlier (lag 1 and lag 2) with those of control days from the same month, matched by temperature and accounting for day of the week (weekend vs week days). We applied conditional logistic regression models to obtain odds ratios (OR) and their 95% CI for an increase of 10 μg/m³ (PM₁₀) or 5 μg/m³ (PM₂.₅) in pollutant concentrations over three lag days (lag 0, 1 and 2). We observed significant associations of PM₁₀ and PM₂.₅ with treatment of acute thrombo-embolic events at the three lags. The strongest associations were observed for air pollution concentrations on the day of the event (lag0). Increases of 10 μg/m³ PM₁₀ and 5 μg/m³ PM₂.₅ on lag0 increased the odds of events treated with endovascular intervention by 2.7% (95%CI:2.3%–3.2%) and 1.3% (95%CI:1%–1.5%), respectively, and they increased the odds of events treated with antithrombotic enzymes by 1.9% (95%CI:1.1–2.7%) and 1.2% (95%CI:0.7%–1.6%), respectively. The associations were generally stronger during autumn months and among children. Our nationwide study confirms that acute exposure to outdoor air pollutants such as PM₁₀ or PM₂.₅ increase the use of medication and interventions to treat thrombo-embolic events.
Show more [+] Less [-]Response strategies of boreal spruce trees to anthropogenic changes in air quality and rising pCO2 Full text
2020
Savard, Martine M. | Bégin, Christian | Marion, Joëlle
Little is known about how forests adjust their gas-exchange mode while atmospheric CO₂ rises globally and air quality changes regionally. The present study aims at addressing this research gap for boreal spruce trees growing in three different regions of Canada, submitted to distinct levels of atmospheric emissions, by examining the amount of carbon gained per unit of water lost in trees, i.e., the intrinsic water use efficiency (iWUE).Under pristine air quality conditions, middle-to long-term trends passed from no-reaction mode to passive strategies due to atmospheric CO₂, and short-term iWUE variations mostly ensue from year-to-year climatic conditions. In contrast, in trees exposed to pollutants from a copper smelter and an oil-sands mining region, air quality deterioration generated swift, long-term iWUE rises immediately at the onset of operations. In this case, the very active foliar strategy sharply reduced the intra-foliar CO₂ (Ci) pressure. Statistical modeling allowed identifying emissions as the main trigger for the iWUE swift shifts; subsequent combined effects of emissions and rising CO₂ led to passive foliar modes in the recent decades, and short-term variations due to climatic conditions appeared all along the series.Overall, boreal trees under different regional conditions modified their foliar strategies mostly without changing their stem growth. These findings underline the potential of acidifying emissions for prompting major iWUE increases due to lowering the stomatal apertures in leaves, and the combined influence of rising CO₂ in modulating other foliar responses. A fallout of this research is that degrading air quality may create true divergences in the relationship between tree-ring isotopes and climatic conditions, an impact to consider prior to using isotopic series for paleo-climatic modeling.
Show more [+] Less [-]Surveillance of antibiotic resistant Escherichia coli in human populations through urban wastewater in ten European countries Full text
2020
Huijbers, Patricia M.C. | Larsson, D.G Joakim | Flach, Carl-Fredrik
Antibiotic resistance surveillance data is lacking in many parts of the world, limiting effective therapy and management of resistance development. Analysis of urban wastewater, which contains bacteria from thousands of individuals, opens up possibilities to generate informative surveillance data in a standardized and resource-efficient way. Here, we evaluate the relationship between antibiotic resistance prevalence in E. coli from wastewater and clinical samples by studying countries with different resistance situations as assessed by traditional clinical surveillance. Composite, influent wastewater samples were collected over 24 h from treatment plants serving major cities in ten European countries. Using a broth screening method, resistance to six antibiotic classes was analyzed for 2507 E. coli isolates (n = 247–252 per country). Resistance prevalence in wastewater E. coli was compared to that in clinical E. coli reported by the European Antibiotic Resistance Surveillance Network. Resistance prevalence was lower in wastewater than clinical E. coli but followed similar geographic trends. Significant relationships were found for resistance to aminopenicillins (R² = 0.72, p = 0.0019) and fluoroquinolones (R² = 0.62, p = 0.0072), but not for aminoglycosides (R² = 0.13, p = 0.31) and third-generation cephalosporins (R² = 0.00, p = 0.99) where regression analyses were based on considerably fewer resistant isolates. When all four antibiotic classes were taken into account, the relationship was strong (R² = 0.85, p < 0.0001). Carbapenem resistance was rare in both wastewater and clinical isolates. Wastewater monitoring shows promise as method for generating surveillance data reflecting the clinical prevalence of antibiotic resistant bacteria. Such data may become especially valuable in regions where clinical surveillance is currently limited.
Show more [+] Less [-]Maternal exposure to ambient air pollution during pregnancy and lipid profile in umbilical cord blood samples; a cross-sectional study Full text
2020
Heydari, Hafez | Abroudi, Mina | Adli, Abolfazl | Pirooznia, Nazanin | Najafi, Moslem Lari | Pajohanfar, Nasim Sadat | Dadvand, Payam | Miri, Mohammad
Adverse health effects of exposure to air pollution have been investigated in many previous studies. However, there is no study available on the association between maternal exposure to air pollution during pregnancy and cord blood lipid profile. This study, based on 150 mother-newborn pairs residing in Sabzevar, Iran (2018), evaluated the association of exposure to ambient air pollution as well as traffic indicators (total street length in different buffers around residential address and distance to major roads) during entire pregnancy with lipid levels cord blood lipid profile. Concentrations of PM₁₀, PM₂.₅, and PM₁ at maternal residential address were estimated using land use regression (LUR) models. We measured triglyceride (TAG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC) levels and TC/HDL-C and TAG/HDL-C ratio in the cord blood samples to characterize their lipid profile. Multiple linear regression models were developed to estimate the association of exposure to air pollution and traffic indicators with cord blood lipid profile controlled for relevant covariates. Higher concentrations of PM₂.₅ and PM₁₀ were associated with higher levels of TAG, TC, HDL-C, TC/HDL-C, and TAG/HDL-C in cord blood samples. Moreover, higher concentration of PM₁ was associated with higher levels of TAG, TC and LDL-C. There was also a positive association between total street length in 100 m buffer around home and serum levels of TC, TAG, LDL-C and TC/HDL ratio (β = 3.73, 95% confidence intervals (CI): 1.76, 5.71; β = 2.75, 95% CI: 0.97, 4.53; β = 1.87, 95% CI: 0.64, 3.09; β = 0.06, 95% CI: 0.01, 0.11, respectively). However, the associations for total street length in larger buffers and distance to major roads were not statistically significant. Our findings support a relationship between exposure to air pollution during pregnancy and increase in cord blood lipid levels.
Show more [+] Less [-]Transcriptome, bioaccumulation and toxicity analyses of earthworms (Eisenia fetida) affected by trifloxystrobin and trifloxystrobin acid Full text
2020
Liu, Tong | Liu, Yalei | Fang, Kuan | Zhang, Xiaolian | Wang, Xiuguo
As a promising fungicide, the potential environmental risk of trifloxystrobin (TFS) and its main metabolism trifloxystrobin acid (TFSA) in soil environment should be given special attention. The present study investigated the potential risks of TFS and TFSA in soil environment to earthworms (Eisenia fetida) through measuring several biomarkers. Residual analysis showed that TFSA was more stable than TFS in artificial soil with half-lives ranging from 138.6 to 231.0 d and 20.4–24.7 d, respectively. Additionally, the accumulation of TFS in earthworms increased in the beginning and then decreased from day 14, while that of TFSA continuously increased. At concentrations of 4.0 mg/kg and 10.0 mg/kg, the weight and lysosomal membrane stability of earthworms were reduced; however, the superoxide dismutase (SOD) activity, glutathione-S-transferase (GST) activity and malondialdehyde (MDA) content in earthworms were enhanced by TFS and TFSA. Moreover, the growth inhibition effect and the oxidative damage level induced by TFSA to earthworms were higher than those induced by TFS. The transcriptome analysis date indicated that the differentially expressed genes (DEGs) in both TFS and TFSA treatments were mainly enriched in ribosome pathway and lysosome pathway, finally affecting the protein synthesis and proteolysis in earthworms. The findings of the present study indicated that TFSA may pose a higher risk in the soil environment than TFS.
Show more [+] Less [-]Perfluorooctane sulfonate enhances mRNA expression of PPARγ and ap2 in human mesenchymal stem cells monitored by long-retained intracellular nanosensor Full text
2020
Gao, Yu | Guo, Xixi | Wang, Siyu | Chen, Fubin | Ren, Xiaomin | Xiao, Huaxin | Wang, Lianhui
Perfluorooctane sulfonate (PFOS) has been widely used as a surface coating for household products. It still exists in living environments despite being restricted, due to its bioaccumulation and long half-life. Studies have shown that PFOS has the ability to induce adipogenic differentiation of human cells. Human mesenchymal stem cells (hMSCs) distributed within the adipose tissue might be a potential target of accumulated PFOS. However, traditional end-point toxicity assays failed to examine the subtle changes of cellular function exposed to low-dose persistent organic pollutants in real time. In the present work, highly sensitive and long-retained (more than 30 days) fluorescence based polymeric nanosensors were developed and employed for real-time assessment of cellular functions. hMSCs were engineered with sensor molecules encapsulated poly (lactic-co-glycolic acid) (PLGA) particles. Once internalized by hMSCs, PLGA particles continuously release and replenish sensor molecules to cytoplasm, resulting in prolonged fluorescence signal against photo bleaching and dilution by exocytosis. With this method, the dynamic changes of viability, ROS induction, and adipogenic differentiation related mRNA expression of hMSCs were monitored. PFOS with the concentration as low as 0.1 μM can induce cellular ROS and enhance the PPARγ and ap2 mRNA expression, suggesting the effect on promoting adipogenic differentiation of hMSCs.
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