Inhibition of Glucose-6-Phosphate Dehydrogenase Could Enhance 1,4-Benzoquinone-Induced Oxidative Damage in K562 Cells

Benzene is a chemical contaminant widespread in industrial and living environments. The oxidative metabolites of benzene induce toxicity involving oxidative damage. Protecting cells and cell membranes from oxidative damage, glucose-6-phosphate dehydrogenase (G6PD) maintains the reduced state of glutathione (GSH). This study aims to investigate whether the downregulation of G6PD in K562 cell line can influence the oxidative toxicity induced by 1,4-benzoquinone (BQ). G6PD was inhibited in K562 cell line transfected with the specific siRNA of G6PD gene. An empty vector was transfected in the control group. Results revealed that G6PD was significantly upregulated in the control cells and in the cells with inhibited G6PD after they were exposed to BQ. The NADPH/NADP and GSH/GSSG ratio were significantly lower in the cells with inhibited G6PD than in the control cells at the same BQ concentration. The relative reactive oxygen species (ROS) level and DNA oxidative damage were significantly increased in the cell line with inhibited G6PD. The apoptotic rate and G2 phase arrest were also significantly higher in the cells with inhibited G6PD and exposed to BQ than in the control cells. Our results suggested that G6PD inhibition could reduce GSH activity and alleviate oxidative damage. G6PD deficiency is also a possible susceptible risk factor of benzene exposure

Integrated analysis of two-lncRNA signature as a potential prognostic biomarker in cervical cancer: a study based on public database

Background Cervical cancer (CC) is a common gynecological malignancy in women worldwide. Evidence suggests that long non-coding RNAs (lncRNAs) can be used as biomarkers in patients with CC. However, prognostic biomarkers for CC are still lacking. The aim of our study was to find lncRNA biomarkers which are able to predict prognosis in CC based on the data from The Cancer Genome Atlas (TCGA). Methods The patients were divided into three groups according to FIGO stage. Differentially expressed lncRNAs were identified in CC tissue compared to adjacent normal tissues based on a fold change >2 and <0.5 at P < 0.05 for up- and downregulated lncRNA, respectively. The relationship between survival outcome and lncRNA expression was assessed with univariate and multivariate Cox proportional hazards regression analysis. We constructed a risk score as a method to evaluate prognosis. We used receiver operating characteristic (ROC) curve and the area under curve (AUC) analyses to assess the diagnostic value of a two-lncRNA signature. We detected the expression levels of the two lncRNAs in 31 pairs of newly diagnosed CC specimens and paired adjacent non-cancerous tissue specimens, and also in CC cell lines. Finally, the results were statistically compared using t-tests. Results In total, 289 RNA sequencing profiles and accompanying clinical data were obtained. We identified 49 differentially expressed lncRNAs, of which two related to overall survival (OS) in CC patients. These two lncRNAs (ILF3-AS1 and RASA4CP) were found together as a single prognostic signature. Meanwhile, the prognosis of patients with low-risk CC was better and positively correlated with OS (P < 0.001). Further analysis showed that the combined two-lncRNA expression signature could be used as an independent biomarker to evaluate the prognosis in CC. qRT-PCR results were consistent with TCGA, confirming downregulated expression of both lncRNAs. Furthermore, upon ROC curve analysis, the AUC of the combined lncRNAs was greater than that of the single lncRNAs alone (0.723 vs 0.704 and 0.685), respectively; P < 0.05. Conclusions Our study showed that the two-lncRNA signature of ILF3-AS1 and RASA4CP can be used as an independent biomarker for the prognosis of CC, based on bioinformatic analysis

A novel living environment exposure matrix of the common organic air pollutants for exposure assessment

Although the most accurate estimations of exposure to organic air pollutants are direct personal measurements, it is prohibitive for large-scale epidemiological studies, both in terms of cost-saving and procedure time. Therefore, indirect exposure assessments offer a potentially feasible approach for estimating population exposures to organic air pollution. The purpose of this study was to develop a novel living environment exposure matrix of the common organic air pollutants, which was used in large-scale epidemiological studies. The common organic air pollutants and a range of potential living environment factors were collected and matched according to the statistics of the Centers for Disease Control and Prevention, the United States Environmental Protection Agency, and the World Health Organization. Paints (dyes), paint removing, and furniture are the most common source of living environment exposure (n = 6). Furthermore, most of the common organic air pollutants are associated with exposure to coal, oil and gasoline burning, smoking, and carpet backing (n ≥ 2). Electricity is considered a clean fuel due to they generate less organic air pollutants compared to other living environment factors in this study. However, whether gas burning is considered as a source of indoor organic air pollutants in large-scale epidemiological studies need to be further investigated. The present study summarizes the living environment exposure matrix of the common organic air pollution, which could be used to estimate exposure to organic air pollutants in large-scale epidemiological studies in the future

Expression Profiling of Exosomal miRNAs Derived from Human Esophageal Cancer Cells by Solexa High-Throughput Sequencing

Cellular genetic materials, such as microRNAs (miRNAs), mRNAs and proteins, are packaged inside exosomes, small membrane vesicles of endocytic origin that are released into the extracellular environment. These cellular genetic materials can be delivered into recipient cells, where they exert their respective biological effects. However, the miRNA profiles and biological functions of exosomes secreted by cancer cells remain unknown. The present study explored the miRNA expression profile and distribution characteristics of exosomes derived from human esophageal cancer cells through Solexa high-throughput sequencing. Results showed that 56,421 (2.94%) unique sequences in cells and 7727 (0.63%) in exosomes matched known miRNAs. A total of 342 and 48 known miRNAs were identified in cells and exosomes, respectively. Moreover, 64 and 32 novel miRNAs were predicted in cells and exosomes, respectively. Significant differences in miRNA expression profiles were found between human esophageal cancer cells and exosomes. These findings provided new insights into the characteristics of miRNAs in exosomes derived from human esophageal cancer cells and the specific roles of miRNAs in intercellular communication mediated by exosomes in esophageal cancer

Investigation into Variation of Endogenous Metabolites in Bone Marrow Cells and Plasma in C3H/He Mice Exposed to Benzene

Benzene is identified as a carcinogen. Continued exposure of benzene may eventually lead to damage to the bone marrow, accompanied by pancytopenia, aplastic anemia or leukemia. This paper explores the variations of endogenous metabolites to provide possible clues for the molecular mechanism of benzene-induced hematotoxicity. Liquid chromatography coupled with time of flight-mass spectrometry (LC-TOF-MS) and principal component analysis (PCA) was applied to investigate the variation of endogenous metabolites in bone marrow cells and plasma of male C3H/He mice. The mice were injected subcutaneously with benzene (0, 300, 600 mg/day) once daily for seven days. The body weights, relative organ weights, blood parameters and bone marrow smears were also analyzed. The results indicated that benzene caused disturbances in the metabolism of oxidation of fatty acids and essential amino acids (lysine, phenylalanine and tyrosine) in bone marrow cells. Moreover, fatty acid oxidation was also disturbed in plasma and thus might be a common disturbed metabolic pathway induced by benzene in multiple organs. This study aims to investigate the underlying molecular mechanisms involved in benzene hematotoxicity, especially in bone marrow cells

A Novel and Native Microcystin-Degrading Bacterium of Sphingopyxis sp. Isolated from Lake Taihu

A native, highly efficient microcystin-LR (MC-LR)-degrading bacterium named a7 was isolated from Lake Taihu and identified as Sphingopyxis sp. by 16S rDNA sequence analysis. The strain a7 could totally degrade MC-LR at a rate of 3.33 mg/(L•h), as detected by high-performance liquid chromatography (HPLC). The mlrA, mlrC, and mlrD genes were detected in the strain a7 by sequence analysis. Tetrapeptide and Adda—which are the middle metabolites of MC-LR—were analyzed via liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS) during degradation. These metabolites were degraded completely, which suggested that the native Sphingopyxis sp. a7 was highly efficient in MC-LR degradation under bench conditions. Thus, strain a7 exhibited a significant potential application for bioremediation in water bodies contaminated by MC-LR produced by harmful cyanobacterial blooms

Recent consequences of micro-nanaoplastics (MNPLs) in subcellular/molecular environmental pollution toxicity on human and animals

Microplastics and Nanoplastics (MNPLs) pollution has been recognized as the important environmental pollution caused by human activities in addition to global warming, ozone layer depletion and ocean acidification. Most of the current studies have focused on the toxic effects caused by plastics and have not actively investigated the mechanisms causing cell death, especially at the subcellular level. The main content of this paper focuses on two aspects, one is a review of the current status of MNPLs contamination and recent advances in toxicological studies, which highlights the possible concentration levels of MNPLs in the environment and the internal exposure of humans. It is also proposed to pay attention to the compound toxicity of MNPLs as carriers of other environmental pollutants and pathogenic factors. Secondly, subcellular toxicity is discussed and the modes of entry and intracellular distribution of smaller-size MNPLs are analyzed, with particular emphasis on the importance of organelle damage to elucidate the mechanism of toxicity. Importantly, MNPLs are a new type of environmental pollutant and researchers need to focus not only on their toxicity, but also work with governments to develop measures to reduce plastic emissions, optimize degradation and control plastic aggression against organisms, especially humans, from multiple perspectives

Aberrant Production of Th1/Th2/Th17-Related Cytokines in Serum of C57BL/6 Mice after Short-Term Formaldehyde Exposure

Previous studies have shown that formaldehyde (FA) could cause immunotoxicity by changing the number of T lymphocytes and that cytokines play a pivotal role in the regulation of T lymphocytes. However, the previously used cytokine detection methods are difficult to use in the measurement of several cytokines in a small amount of sample for one test. Therefore, the cytometric bead array (CBA) technique was used. CBA showed better analytical efficiency and sensitivity than the previous methods. C57BL/6 mice were exposed to the control (normal saline), low FA concentration (0.5 mg/kg), and high FA concentration (2 mg/kg) for 1 week or 1 month. The contents of cytokines, including Th1-related cytokines (IL-2, IFN-γ, and tumor necrosis factor), Th2-related cytokines (IL-4, IL-6, and IL-10), and Th17-related cytokines (IL-17A), were measured by using the BD FACS Canto II Flow Cytometer and analyzed by FCAP ArrayTM Software. Th1/Th2/Th17-related cytokines showed a slightly decreasing trend after low FA exposure. Conversely, a significantly increasing trend was found after high FA exposure. Th1/Th2/Th17-related cytokines all serve important functions in the immune reactions in mice after FA exposure

Metabolic risk factors link unhealthy lifestyles to the risk of colorectal polyps in China

Colorectal cancer is the second leading cause of global cancer-related deaths, and its precursor lesions are colorectal polyps (CAP). The study aimed to explore the effect of combinations of unhealthy lifestyles on CAP and investigate the mediation role of metabolic disorder in this process. A total of 1299 adults were recruited from a hospital in Jiangsu, China, including 811 cases and 488 adults without diseases. The information on demographic characteristics and lifestyles was collected through questionnaires and the medical record system. Serum biochemical parameters were determined using the automatic biochemical analyzer. Adjusted regression analysis showed that unhealthy lifestyles, including smoking, overnight meals, daily water intake, staying up late, and exercise associated with the risk of CAP. Furthermore, metabolic biomarkers, including BMI, triglycerides, and uric acid, were associated with the risk of CAP. Also, unhealthy lifestyle scores were positively associated with BMI, triglycerides, and CAP. The mediation effect of metabolic biomarkers, such as BMI and triglycerides on the association of unhealthy lifestyle scores with CAP was significant. Available data demonstrate the adverse effect of combinations of unhealthy lifestyle factors on CAP, and metabolic disorders to potentially mediate the association of unhealthy lifestyles with the risk of CAP