The interaction effects of coke oven emissions exposure and metabolic enzyme Gene variants on total antioxidant capacity of workers

Chain-mediating effect of interaction between telomeres and mitochondria under oxidative stress in coke oven workers

Coke oven emissions (COEs) exposure leads to oxidative stress, an imbalance between oxidant production and antioxidant defence in the body, which then leads to shortened relative telomere length (RTL) and reduced mitochondrial DNA copy number (mtDNAcn), ultimately leading to ageing and disease. By analysing the relationship among COEs, oxidative stress, RTL and mtDNAcn, we investigated the chain-mediating effects of oxidative stress and telomeres on mitochondrial damage and mitochondria on telomere damage in coke oven workers. A total of 779 subjects were included in the study. Cumulative COEs exposure concentrations were estimated, and the RTL and mtDNAcn of peripheral blood leukocytes were measured using real-time fluorescence quantitative PCR. Total antioxidant capacity (T-AOC) was measured to reflect the level of oxidative stress. The data were statistically analysed using SPSS 21.0 software and discussed using mediation effect analysis. After adjusting for age, sex, smoking, drinking and BMI, generalised linear model revealed dose-response associations between COEs and T-AOC, RTL and mtDNAcn, respectively. (Ptrend < 0.05). The results of chain-mediating effect showed that the proportion of the chain-mediating effect of "CED-COEs→T-AOC→ RTL→mtDNAcn" was 0.82% (β = -0.0005, 95% CI = [-0.0012, -0.0001]), and the proportion of the chain-mediating effect of "CED-COEs→T-AOC→ mtDNAcn → RTL ″ was 2.64% (β = -0.0013, 95% CI = [-0.0025, -0.0004]). After oxidative stress is induced by COEs, mitochondria and telomeres may interact with each other while leading further to potential bodily damage. This study provides clues to explore the association between mitochondria and telomeres.

Polystyrene Microplastics Induce Oxidative Stress in Mouse Hepatocytes in Relation to Their Size

Microplastics have become a new type of environmental pollutant that can accumulate in various tissues and organs of the body and cause chronic damage. In this study, two different size polystyrene microplastics (PS-MPs, 5 μm and 0.5 μm) exposure models were established in mice to investigate the effects of PS-MPs with different particle sizes on oxidative stress in the liver. The results showed that PS-MPs exposure caused a decrease in body weight and liver-to-body weight. The hematoxylin and eosin staining and transmission electron microscopy results showed that exposure to PS-MPs led to the disorganized cellular structure of liver tissue, nuclear crinkling, and mitochondrial vacuolation. The extent of damage in the 5 μm PS-MP exposure group was more extensive when compared with the other group. The evaluation of oxidative-stress-related indicators showed that PS-MPs exposure exacerbated oxidative stress in hepatocytes, especially in the 5 μm PS-MPs group. The expression of oxidative-stress-related proteins sirtuin 3(SIRT3) and superoxide dismutase (SOD2) was significantly reduced, and the reduction was more pronounced in the 5 μm PS-MPs group. In conclusion, PS-MPs exposure led to oxidative stress in mouse hepatocytes and caused more severe damage in the 5 μm PS-MPs group when compared with the 0.5 μm PS-MPs group.

PBDEs disrupt homeostasis maintenance and regeneration of planarians due to DNA damage, proliferation and apoptosis anomaly

Polybrominated diphenyl ethers (PBDEs) are widely used as brominated flame retardants in the manufacturing industry, belonging to persistent organic pollutants in the environment. Planarians are the freshwater worms, with strong regenerative ability and extreme sensitivity to environmental toxicants. This study aimed to evaluate the potential acute comprehensive effects of PBDE-47/-209 on freshwater planarians. Methods to detect the effects include: detection of oxidative stress, observation of morphology and histology, detection of DNA fragmentation, and detection of cell proliferation and apoptosis. In the PBDE-47 treatment group, planarians showed increased oxidative stress intensity, severe tissue damage, increased DNA fragmentation level, and increased cell proliferation and apoptosis. In the PBDE-209 treatment group, planarians showed decreased oxidative stress intensity, slight tissue damage, almost unchanged DNA fragmentation level and apoptosis, proliferation increased only on the first day after treatment. In conclusion, both PBDE-47 and PBDE-209 are dangerous environmental hazardous material that can disrupt planarians homeostasis, while the toxicity of PBDE-47 is sever than PBDE-209 that PBDE-47 can lead to the death of planarians.

Effects of Dietary Koumine on Growth Performance, Intestinal Morphology, Microbiota, and Intestinal Transcriptional Responses of Cyprinus carpio

Gelsemium elegans Benth. (GEB) is a traditional medicinal plant in China, and acts as a growth promoter in pigs and goats. Koumine (KM) is the most abundant alkaloid in GEB and produces analgesic, anti-cancer, and immunomodulatory effects. KM can be used as an aquatic immune stimulant, but its growth-promoting effects and transcriptional mechanisms have not been investigated. Diets containing KM at 0, 0.2, 2, and 20 mg/kg were fed to Cyprinus carpio for 71 days to investigate its effects on growth performance, intestinal morphology, microflora, biochemical indicators, and transcriptional mechanisms. Cyprinus carpio fed with KM as the growth promoter, and the number of intestinal crypts and intestinal microbial populations were influenced by KM concentration. KM increased the abundance of colonies of Afipia, Phyllobacterium, Mesorhizobium, and Labrys, which were associated with compound decomposition and proliferation, and decreased the abundance of colonies of pathogenic bacteria Methylobacterium-Methylorubrum. A total of 376 differentially-expressed genes (DEGs) among the four experimental groups were enriched for transforming growth factor-β1 and small mother against decapentaplegic (TGF-β1/Smad), mitogen-activated protein kinase (MAPK), and janus kinases and signal transducers and activators of transcription (Jak/Stat) signaling pathways. In particular, tgfbr1, acvr1l, rreb-1, stat5b, smad4, cbp, and c-fos were up-regulated and positively correlated with KM dose. KM had a growth-promoting effect that was related to cell proliferation driven by the TGF-β1/Smad, MAPK, and Jak/Stat signaling pathways. KM at 0.2 mg/kg optimized the growth performance of C. carpio, while higher concentrations of KM (2 and 20 mg/kg) may induce apoptosis without significantly damaging the fish intestinal structure. Therefore, KM at low concentration has great potential for development as an aquatic growth promotion additive.

Relationship between miRNAs polymorphisms and peripheral blood leukocyte DNA telomere length in coke oven workers: A cross-sectional study

OBJECTIVE

The purpose of this study was to investigate the factors affecting telomere length (TL) in coke oven workers by analyzing the interaction between miRNAs polymorphisms and coke oven emissions (COEs) exposure.

METHODS

A total of 544 coke oven workers and 238 healthy controls were recruited. Peripheral blood was collected from the subjects, genomic DNA was extracted, leukocyte TL was detected by real-time quantitative polymerase chain reaction, and fifteen polymorphisms of eight miRNAs were genotyped by flight mass spectrometry.

RESULTS

Statistical analysis showed that the peripheral blood DNA TL in the exposure group was shorter than that in the control group (P < 0.001). Generalized linear model found that COEs-exposure [β (95%CI) = -0.427 (-0.556, -0.299), P < 0.001], genotype CC+CT for miR-612 rs1144925 [β (95%CI) = -0.367 (-0.630, -0.104), P = 0.006], and the interaction of miR-181B1 rs12039395 TT genotype and COEs-exposure [β (95% CI) = 0.564 (0.108, 1.020), P = 0.015] were associated with the shortened TL.

CONCLUSION

COEs-exposure and miR-612 rs1144925 TT could promote telomere shortening in coke oven workers. The interaction of miR-181B1 rs12039395 TT genotype and COEs-exposure could protect telomere. This provides clues for further mechanistic studies between miRNA and telomere damage.

The Association Between Polymorphisms in Cell-Cycle Genes and Mitochondrial DNA Copy Number in Coke Oven Workers

The mitochondrial DNA (mtDNA) copy number is a vital component in maintaining normal mitochondrial function. It is affected by environmental and occupational exposures, as well as polymorphisms in nuclear genes. Nonetheless, the specific roles of polymorphisms in cell-cycle genes and mtDNA copy number are still unknown. This study enrolled a sample of 544 coke oven workers and 238 non-exposed controls so as to assess the effect of exposure of coke oven emissions (COEs) and polymorphisms in cell-cycle genes on the mtDNA copy number. We found that the mtDNA copy number in the exposed group (0.60 ± 0.29) was significantly lower than that in the control group (1.03 ± 0.31) (t =18.931, P < 0.001). The analysis of covariance showed that both the rs1801270 (CA+CC) and the rs1059234 (CT+CC) in p21 gene were associated with lower mtDNA copy number in the exposed group (P = 0.001). Generalized linear models indicated COEs-exposure (β = -0.432, P < 0.001) and rs1059234 (CT+CC) in p21 gene (β = -0.060, P = 0.024) were the factors in mtDNA copy number reduction. In conclusion, this study suggests that the decrease of the mtDNA copy number is associated with COEs-exposure and the rs1059234 (CT+CC) in the p21 gene.

Effects of Bacillus licheniformis on Growth Performance, Diarrhea Incidence, Antioxidant Capacity, Immune Function, and Fecal Microflora in Weaned Piglets

Simple Summary

Bacillus licheniformis has been shown to be safe as a green additive in food and feed. This experiment was conducted to investigate the value of Bacillus licheniformis in the diet of piglets. Our results suggested that dietary Bacillus licheniformis supplementation plays an important role in improving the average daily gain, alleviating diarrhea, improving antioxidant capacity, promoting immune function, and regulating the intestinal microflora of weaned piglets.

Abstract

Bacillus licheniformis (B. licheniformis) is a safe probiotic that can promote animal growth and inhibit pathogenic bacteria. This study aimed to assess the effects of B. licheniformis, one green feed additive, on growth performance, diarrhea incidence, immune function, fecal volatile fatty acids, and microflora structure in weaned piglets. Weaned piglets (n = 180) were randomly divided into three treatment groups and fed a basal diet and a basal diet supplemented with 500 mg B. licheniformis per kg and 1000 mg B. licheniformis per kg, respectively. The dietary 500 mg/kg B. licheniformis inclusion improved the average daily gain, reduced diarrhea incidence, and strengthened antioxidant capacity. Piglets supplemented with B. licheniformis presented increased serum immunoglobulins (IgA, IgM) compared to the CON group. Meanwhile, the expression of anti-inflammation factors was increased, and the levels of pro-inflammation factors were reduced after B. licheniformis administration. Moreover, the levels of volatile fatty acids, including acetic acid, propionic acid, butyric acid, isobutyric acid, and isovaleric acid, in the BL500 and BL1000 groups were increased compared with the CON group, and the concentration of valeric acid was higher in the BL500 group. Furthermore, piglets in the 500 mg/kg B. licheniformis addition group significantly altered fecal microbiota by increasing Clostridium_sensu_stricto_1 and Oscillospira. In conclusion, dietary B. licheniformis relieved diarrhea, enhanced antioxidant capacity, immunity function, and fecal microflora structure in weaned pigs.

Microplastics exposure causes oxidative stress and microbiota dysbiosis in planarian Dugesia japonica

Planarians are widely used as water quality indicator species to provide early warning of harmful pollution in aquatic ecosystems. However, the impact of microplastics on freshwater planarians remains poorly investigated. Here we simulated waterborne microplastic exposure in the natural environments to examine the effect on the antioxidant defense system and microbiota in Dugesia japonica. The results showed that exposure to microplastics significantly changed the levels of antioxidant enzymes, including superoxide dismutase, catalase, and glutathione S-transferase, indicating that microplastic exposure induces oxidative stress in planarians. High-throughput 16S rRNA gene sequencing results revealed that exposure to microplastics altered the diversity, abundance, and composition of planarian microbiota community. At phylum level, the relative abundance of the dominant phyla Proteobacteria and Bacteroidetes changed significantly after microplastic exposure. At genus level, the abundance of dominant genera also changed significantly, including Curvibacter and unclassified Chitinophagales. Predictive functional analysis showed that the microbiota of microplastic-exposed planarians exhibited an enrichment in genes related to fatty acid metabolism. Overall, these results showed that microplastics can cause oxidative stress and microbiota dysbiosis in planarians, indicating that planarians can serve as an indicator species for microplastic pollution in freshwater systems.

Impact of environmental mercury exposure on the blood cells oxidative status of fishermen living around Mundaú lagoon in Maceió - Alagoas (AL), Brazil

Mercury in the aquatic environment can lead to exposure of the human population and is a known toxic metal due to its capacity for accumulation in organs. We aimed to evaluate the mercury level in the blood and urine of fishermen and correlate it with the level of oxidative stress in blood cells. We show in this case-control study that the fishermen of the exposed group (case) of Mundaú Lagoon (Maceió - Alagoas, Brazil) have higher concentrations of total mercury in the blood (0.73-48.38 μg L^-1) and urine (0.430-10.2 μg L^-1) than the total mercury concentrations in blood (0.29-17.30 μg L^-1) and urine (0.210-2.65 μg L^-1) of the control group. In the blood cells of fishermen, we observed that the lymphomononuclear cells produced high levels of reactive oxygen species (61.7%), and the erythrocytes presented increased lipid peroxidation (151%) and protein oxidation (41.0%) and a decrease in total thiol (36.5%), GSH and the REDOX state (16.5%). The activity of antioxidant system enzymes (SOD, GPx, and GST) was also reduced in the exposed group by 26.9%, 28.3%, and 19.0%, respectively. Furthermore, hemoglobin oxygen uptake was decreased in the exposed group (40.0%), and the membrane of cells presented increased osmotic fragility (154%) compared to those in the control group. These results suggest that mercury in the blood of fishermen can be responsible for causing impairments in the oxidative status of blood cells and is probably the cause of the reduction in oxygen uptake capacity and damage to the membranes of erythrocytes.

Genetic polymorphisms of metabolic enzyme genes associated with leukocyte mitochondrial DNA copy number in PAHs exposure workers

BACKGROUND

Polycyclic aromatic hydrocarbons (PAHs) exposure had been reported to be a risk factor of mtDNAcn in our early study. However, the effect of metabolic enzymes' genetic polymorphisms on mtDNAcn in PAHs-Exposure workers has not been fully evaluated.

AIM

The aim of the study was to explore the effect of metabolic enzymes' genetic polymorphisms on mtDNAcn in PAHs-Exposure.

METHODS AND RESULTS

We investigated the effects of metabolic enzymes' genetic polymorphisms on mtDNAcn among 544 coke oven workers and 238 office staffs. The mtDNAcn of peripheral blood leukocytes was measured using the Real-time quantitative polymerase chain reaction (PCR) method. PCR and restriction fragment length was used to detect five polymorphisms in GSTT1, GSTM1, GSTP1 rs1695, CYP2E1 rs6413432, and CYP2E1 rs3813867. The mtDNAcn in peripheral blood leukocytes was significantly lower in the exposure group than that in the control group (p < .001). The 1-OHPYR had an increasing trend with the genotypes AA→AG → GG of GSTP1 rs1695 in the control group. Generalized linear model indicated that the influencing factors of mtDNAcn were PAHs-exposure [β (95% CI) = -0.420 (-0.469, -0.372), p < .001], male [β (95% CI) = -0.058 (-0.103, -0.012), p = .013], and AA genotype for GSTP1 rs1695 [β (95% CI) = -0.051 (-0.095, -0.008), p = .020].

CONCLUSION

The individuals carrying the AA genotype of GSTP1 rs1695 may have a lower mtDNAcn due to their weaker detoxification of PAHs.

Antioxidant responses and lipid peroxidation can be used as sensitive indicators for the heavy metals risk assessment of the Wei River: a case study of planarian Dugesia Japonica

PURPOSE

To verify antioxidant responses and lipid peroxidation can be used as sensitive indicators for the risk assessment of the Wei River.

MATERIAL AND METHODS

We investigate the effects of the Wei River on oxidative stress of planarian Dugesia japonica by antioxidant parameters, and use ICP-MS to measure the heavy metals in the Wei River. Then, we observe the effects of three common heavy metal ions (Cr³⁺, Hg²⁺, Pb²⁺) on the regeneration of planarians on morphological and histological levels.

RESULTS

The significant changes of antioxidant parameters (SOD, CAT, GPx, GST, T-AOC) and MDA content indicate that oxidative stress is induced after the Wei River exposure on planarians, though the heavy metals in the Wei River are not exceeding the standards. Then, the regeneration of planarians shows different degree of morphological and histological damage after Cr³⁺, Hg²⁺ and Pb²⁺ exposure.

CONCLUSION

We speculate that the heavy metal ions in the Wei River, especially Cr³⁺, Hg²⁺ and Pb²⁺, may give rise to oxidative damage on planarians. These findings illustrate that planarian can serve as an indicator of aquatic ecosystem pollution, antioxidant responses and lipid peroxidation can also be used as sensitive indicators and provide an excellent opportunity for urban river risk assessment.

Benchmark dose estimation for coke oven emissions based on oxidative damage in Chinese exposed workers

Coke oven emissions (COEs) can cause oxidative stress of the body, which in turn induces the occupational lung disease and also increases the risk of other diseases. COEs are the major occupational hazard factors for coke oven workers. The aim of the study is to explore the influences of COEs exposure on oxidative damage and estimate the benchmark dose (BMD) of COEs. A group of 542 workers exposed to COEs and 237 healthy controls from the same city were recruited in this study. The corresponding measuring kits were used to determine the plasma biomarkers of oxidative damage level. Generalized linear models and trend tests were used to analyze the relationship between COEs exposure and biomarkers. EPA Benchmark Dose Software was performed to calculate BMD and the lower confidence limit of the benchmark dose (BMDL) of COEs exposure. A significant association was observed between COEs exposure and oxidative damage with T-AOC as a biomarker. The BMD of COEs exposure were 2.83 mg/m³ and 1.39 mg/m³ for males and females, respectively, and the corresponding BMDL were 1.47 mg/m³ and 0.75 mg/m³, respectively. Our results suggested that the exposure level of COEs below the current national occupational exposure limits (OELs) would induce oxidative damage, and the OEL of COEs based on the T-AOC damage was suggested at 0.03 mg/m³ in this study.

Effects of polycyclic aromatic hydrocarbon exposure and miRNA variations on peripheral blood leukocyte DNA telomere length: A cross-sectional study in Henan Province, China

Telomeres play a major role in human aging and disease, especially in most cancers. Telomere length was shortened in workers exposed to polycyclic aromatic hydrocarbons (PAHs) and influenced by individual genetic variations in telomere-binding proteins. MicroRNAs (miRNAs) can affect the progress of messenger RNA (mRNA) transcription; however, whether polymorphisms in miRNA can act on the telomere length is still unknown. Therefore, we aimed to explore the relationships between telomere damage and genetic polymorphisms in miRNA or environmental exposure. A total of 544 coke oven workers and 238 healthy controls were recruited. After collecting peripheral blood and extracting the genomic DNA of the study subjects, the telomere length (TL) in their leucocytes was detected by a real-time quantitative polymerase chain reaction (PCR), and polymorphisms in miRNAs were genotyped using the flight mass spectrometry technique. The concentrations of the four urine OH-PAHs were determined by high performance liquid chromatography (HPLC), and the Soxhlet extraction method was used to detect the concentration of coke oven emissions (COEs) in the air. We found that the peripheral blood leucocyte DNA TL was significantly shorter in the exposure group (0.75; 0.51, 1.08) than that in the control group (1.05; 0.76, 1.44) (Z = 7.692, P < 0.001). The total cumulative exposure dose (CED), 1-hydroxypyrene, 2-hydroxynaphthalene, and 3-hydroxyphenanthrene were significantly negatively correlated with TL (r = -0.307, P < 0.001; r = -0.212, P < 0.001; r = -0.110, P = 0.025; r = -0.251, P < 0.001, respectively). MiR-145 rs353291 GG, miR-30a rs2222722 CT/CC, and miR-197 rs1889470 AA could protect the telomere end in the exposed workers (P < 0.05). The interaction between miR-197 rs1889470 and the CED had an effect on TL (β = 0.066, P = 0.034). This is the first study to evaluate gene-environmental interactions for miRNA polymorphisms and PAH exposure in coke oven workers.