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Background Imidacloprid is a neonicotinoid insecticide that is widely used in agricultural production, with a high detection rate in human biological samples. Previous studies have shown a high correlation between imidacloprid exposure and liver injury, but the specific mechanism is still unknown. Objective To observe potential toxic effects of HepG2 cells and its perturbation of non-targeted metabolic profile after imidacloprid exposure, and to explore possible molecular mechanisms of hepatotoxicity of imidacloprid by analyzing invovlved biological processes and signaling pathways. Methods HepG2 cell suspension was prepared and seeded in a 96-well plate, which was divided into blank control group, dimethyl sulfoxide (DMSO) solvent control group and imidacloprid exposure groups with multiple concentrations. Each group was set with 5 parallel samples. The viability of HepG2 cells viability were determined after 8 h of exposure to different concentrationsof imidacloprid (1, 2.5, 5, 7.5, 10 mmol·L−1), and the dose-effect relationship was analyzed. A proper concentration (3 mmol·L−1 with 80% viability) was chosen for imidacloprid exposure, non-targeted metabolomic analysis was applied to the cultivated HepG2 cells using UHPLC-Q-TOF/MS technology, the differential metabolites between groups were screened, and the bioprocess and related signaling pathways of their enrichment were annotated using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. Results Compared to the other two groups, the survival rates of HepG2 cells in the imidacloprid exposure groups decreased. A survival rate of about 86% of HepG2 cells was found in HepG2 cells exposed to 2.5 mmol·L−1 imidacloprid exposure. The non-targeted metabolomics studies showed that 61 metabolites were significantly affected in HepG2 cells after 3 mmol·L−1 imidacloprid exposure, including creatine (variable importance in projection VIP=1.11, P<0.001), arginine (VIP=1.47, P=0.048), taurine (VIP=4.28, P=0.001), and α-D-glucose (VIP=1.90, P=0.006). The differential metabolites enriched in bioprocess and related signaling pathways were mainly directed to mTOR signaling pathways (P<0.001), arginine and proline metabolism (P=0.002), and galactose metabolism (P=0.015). Conclusion Imidacloprid exposure can significantly inhibit the survival rate of HepG2 cells, and interfere with the mTOR signaling pathway, arginine and proline metabolism, galactose metabolism, and so on.
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Background Atmospheric fine particulate matter (PM2.5) can induce abnormal early embryo development, resulting in adverse pregnancy outcomes such as embryo damage and spontaneous abortion. The vascular remodeling of maternal-fetal interface regulated by hypoxia inducible factor-1α (HIF-1α)/vascular endothelial growth factor (VEGF) axis is a key link in early embryo development. Objective To investigate the effects of pre-pregnancy PM2.5 exposure on the uterine state of mice before conception and the vascular remodeling of maternal-fetal interface after conception, and to further explore the regulatory role of the HIF-1α/VEGF axis. Methods Forty eight-week-old C57BL/6J sexually mature female mice and several males (for mating, without any treatment) were adaptive fed for 1 week. The female mice were divided into a PM2.5 exposure group and a control group, 20 mice per group. The PM2.5 exposure group was given 3 mg·kg−1 PM2.5 suspension by nasal instillation, once every other day for four weeks; the control group were treated with the same dose of blank sampling membrane suspension. Body weight of the mice was recorded every week during the experimental period. At the end of the exposure, six mice from each group were sacrificed. Then the uterus was weighted and its organ coefficients were calculated, a histopathological morphology evaluation was conducted by HE staining, and the mRNA expressions of HIF-1α, VEGF and its receptors Flt-1 and Flk-1 in the uterus samples were further examined. The remaining 14 female mice in each group were caged with male mice overnight with a sex ratio of 2:1, then we calculated the pregnancy rate. On gestation day 10 (GD10), the female mice were decapitated and the uterus was dissected, the histopathological morphology of embryo and placenta were observed by HE staining, and the mRNA expressions of HIF-1α, VEGF and its receptors Flt-1 and Flk-1 were detected as well in the uterus samples. Results Compared with the control group, the pre-pregnancy PM2.5 exposure had no significant effect on body weight gain of the female mice, but decreased uterine organ coefficient, accompanied by pathological damage such as endometrium thinning as well as decreased mRNA expressions of HIF-1α, VEGF and its receptors Flt-1 and Flk-1 (all Ps<0.05). After mating, the pre-pregnancy PM2.5 exposure induced a decrease of the pregnancy rate (control group: 9/14; exposure group: 5/14) and abnormal embryo arrangement, small placenta, narrowing of spiral arteries (control group: 1.00±0.06; exposure group: 0.86±0.08; P=0.01), as well as significant decreases in HIF-1α, VEGF and its receptor Flk-1 mRNA expressions. (all Ps <0.05). Conclusion Pre-pregnancy PM2.5 exposure has adverse effects on the pathological structure and angiogenesis in female mice uterus, leading to abnormal vascular network remodeling at the mother-fetal interface after conception, and the HIF-1α/VEGF axis may play a regulatory role.
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Objective:To explore the modulatory effects of GSK-3β/β-catenin signaling pathway on anxiety- and depression-like behavior of mice induced by chronic sleep deprivation (CSD).Methods:Forty-eight 10-week-old C57BL/6J male mice were selected and randomly divided into four groups(with 12 mice in each group): control group, inhibitor-only group (LiCl), chronic sleep deprivation group (CSD) and inhibitor with CSD group (LiCl+ CSD). Elevated plus maze (EPM) and forced swimming test (FST) were used to evaluate the behavior of mice, HE staining was used to observe the pathological morphological changes of hippocampal neurons, and Western blot was used to detect the protein expressions of β-catenin, GSK-3β and p-GSK-3β in hippocampal tissues. SPSS 22.0 software was used for independent sample t-test and one way ANOVA. Results:After modeling, the body weight of mice in the CSD group ((26.53±0.76)g) was significantly lower than that of the control group ((28.00±0.37)g) ( q=4.119, P=0.041), and the body weight in the LiCl+ CSD group ((28.04±0.86)g) was improved compared with CSD group ( q=4.240, P=0.036). In EPM, the ratio of the entering times and the proportion of the staying time in the open arm in the CSD group ((48.44±9.16)%) and ((16.47±10.42)%) were significantly lower than those in the control group ((68.92±11.71)% and (42.93±15.89)%) ( q=4.660, P=0.018, q=4.346, P=0.029), but the staying time in the open arm in the LiCl+ CSD group ((32.92±12.05)%) was significantly higher than that in the CSD group ( q=2.432, P=0.038). In FST, the percentage of floating immobility time of the mice in the CSD group ((55.00±5.36)%) was significantly longer than that of the control group ((39.95±2.87)%) ( P=0.023), which was decreased significantly in the LiCl+ CSD group ((42.00±7.92)%) than that in the CSD group ( P=0.040). Western blot results showed that, the expressions of p-GSK-3β and β-catenin in the hippocampus of CSD group were decreased significantly ( P=0.040, P=0.008), while the expression of GSK-3β was significantly increased than that of the control group ( P<0.001). Both p-GSK-3β and β-catenin were significantly reversed in CSD+ LiCl group than that in CSD ( P=0.034, P=0.038). Conclusion:The GSK-3β/β-catenin signaling pathway may be involved in the regulation of CSD-induced anxiety and depression-like behaviors in mice.
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Objective To explore the effect of polychlorinated biphenyls (PCBs) on the learning and memory of gestational and lactational exposure to polychlorinated biphenyls in rats offspring.Methods The PCB mixture (A1254,0,5,10,20 mg/kg body weight) was administered to pregnant wistar rats every 3 days by gavage from gestational day (GD) 5 to postnatal day (PND) 20.To assess the effects on offspring following such exposure,Morris water maze test was performed to assess the learning and memory ability.Calcium concentration was assayed in hippocampus and the ultramicro structure was observed.Results After training for four days,the escaping latency in every group decreased significantly compared with the first day,especially the control group,the results in the fourth day decreased significantly with the early three days(P＜0.05).The offsprings of the 10 and 20 mg/kg had prolonged time of passing the aim target ((5.23± 1.16) s,(7.90±3.21) s,(11.74±6.56) s and (20.83± 8.38) s ; P＜0.05),decreased number of crossing platform ((4.14± 1.21),(3.00± 1.32),(2.65± 1.13),(2.42± 1.31) ; P＜0.05) and swimming time in the target area ((40.14±7.14)s,(33.76±5.58)s,(32.45±6.00)s and (30.63±5.10) s; P＜0.05)compared with those of the rats of control and 5 mg/kg groups.The calcium concentration increased ((121.16± 12.23) nM,(141.27±24.66) nM,(163.32±29.75) nM,(261.46±27.79) nM) and the ultramicro structure in hippocampus changed obviously in the high exposure group.Conclusion Gestational and lactational exposure to aroclor 1254 in rats could affect the leaming and memory ability of offsprings.
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<p><b>OBJECTIVE</b>To investigate the inherent characteristics of Vibrio cholerae (V. cholerae) and other vibrios and their relationship.</p><p><b>METHODS</b>Polymerase chain reaction (PCR), DNA sequence analysis, randomly amplified polymorphic DNA (RAPD) analysis and average linkage cluster analysis were used to study 3 isolates of V. cholerae strains O139, three isolates O1 biotype El Tor, four isolates O1 biotype classical and 3 other vibrios.</p><p><b>RESULTS</b>V. cholerae O139 contained the genomic sequences of ctx A2-B as well as V. cholerae O1. V. cholerae and others vibrios were divided into 4 groups by fingerprint patterns of RAPD, that is (1) V. cholerae O139 and V. cholerae O1 El Tor; (2) V. cholerae O1 classical; (3) V. paraheamolyticus and V. vulnificus and (4) V. flluvialis. V. cholerae O139 DNA fingerprint of RAPD was consistent with the El Tor biotype: average linkage cluster distance was 0, and slightly different from the classical biotype, with a distance of 2.07. It was much more different from vibrio paraheamolyticus and others, with a distance of 6.76 - 8.54.</p><p><b>CONCLUSION</b>V. cholerae and other vibrios are polymorphic in inherent characteristics. The inherent characteristics of V. cholerae O139 are the same as El Tor biotype. O139 may have evolved from the El Tor biotype. The inherent characteristics of vibrio paraheamolyticus are the same as vibrio vulnificus.</p>