Prodigiosin inhibits the proliferation of glioblastoma by regulating the KIAA1524/PP2A signaling pathway.

Prodigiosin (PG), a member of a family of natural red pigments produced by a variety of bacteria, was first discovered in Serratia marcescens. PG has been reported to have an apoptosis-inducing effect in many cancers, such as lymphoma, colon cancer and nasopharyngeal carcinoma. For this study, we used three glioblastoma (GBM) cell lines (LN229, U251 and A172) to explore the effect of prodigiosin on GBM cells. A CCK8 assay was used to evaluate cell viability. We determinedthe cell cycle distribution by flow cytometry and measured proliferation by an EdU incorporation assay. The expression of different molecules was investigated by western blotting and RT-PCR. We further confirmed our results by plasmid transfection and lentiviral transduction. The LN229 xenograft model was used to study the effect of prodigiosin in vivo. We confirmed that prodigiosin played an anticancer role in several GBM cell lines through the KIAA1524/PP2A/Akt signalling pathway. Prodigiosin inhibited the protein expression of KIAA1524 by suppressing its transcription, which led to activation of PP2A. Afterward, PP2A inhibited the phosphorylation of Akt, thereby inducing increased expression of p53/p21. Furthermore, it was verified that prodigiosin inhibited the KIAA1524/PP2A/Akt axis in vivo in the LN229 xenograft model. These data improve the understanding of the anticancer effects of prodigiosin and further highlight the potential of prodigiosin for the development of anti-glioma drugs.

The risk of perchlorate and iodine on the incidence of thyroid tumors and nodular goiter: a case-control study in southeastern China.

BACKGROUND: The incidence rates of thyroid tumors and nodular goiter show an upward trend worldwide. There are limited reports on the risk of perchlorate and iodine on thyroid tumors, but evidence from population studies is scarce, and their impact on thyroid function is still uncertain. Therefore, the objective of this study was to investigate the association of perchlorate and iodine with the risk of nodular goiter (NG), papillary thyroid microcarcinoma (PTMC), and papillary thyroid carcinoma (PTC) and to assess the correlation between perchlorate and iodine with thyroid function indicators. METHODS: A case-control population consisting of 184 pairs of thyroid tumors and nodular goiter matched by gender and age (±2 years) was recruited in this study. Serum and urine samples were collected from each participant. Thyroid function indicators in serum were tested by automatic chemical immunofluorescence, and perchlorate and iodine levels in urine were determined by ultra-high performance liquid chromatography tandem-mass spectrometry and inductively coupled plasma-mass spectrometry, respectively. Conditional logistic regressions and multiple linear regressions were used to analyze the associations. RESULTS: Urinary perchlorate concentration was significantly higher in total cases, NG and PTC than in the corresponding controls (P < 0.05). Perchlorate was positively associated with PTC (OR = 1.058, 95% CI: 1.009, 1.110) in a non-linear dose-response relationship, but there was no association between perchlorate and NG or PTMC. Iodine was not associated with the risk of thyroid tumors and NG and did not correlate with the thyroid function indicators. Furthermore, perchlorate showed a positive correlation with thyroid stimulating hormone (TSH) at iodine adequate levels (P < 0.05), and a negative correlation with free triiodothyronine (FT3) and a positive correlation with thyroglobulin antibody (TgAb) at iodine more than adequate or excess levels (P < 0.05). CONCLUSIONS: Perchlorate can increase the risk of PTC in a non-linear dose-response relationship and disturb the thyroid hormone homeostasis and thyroid autoantibody levels.

A case-control study on the association of mineral elements exposure and thyroid tumor and goiter.

Thyroid tumor and thyroid goiter are prevalent disease around the world. In this case-control study, we investigated the association between exposure to a total of twelve mineral elements and thyroid disease as well as thyroid functions. Participants with thyroid tumor or goiter (N = 197) were matched with a healthy population (N = 197) by age (± 2 years old) and same sex. Questionnaires were used to collect data about the demographic characteristics and information of subjects. Serum and urine samples were collected simultaneously for each of the subjects. Mineral elements, iodine level of urine and levels of the total seven thyroid function indexes in serum were detected respectively. Conditional logistic regression was applied to estimate the associations between mineral elements and the risk of thyroid tumor and goiter through single-element models and multiple-element models. Multiple linear regression was used to evaluate relationships between mineral elements and percentage changes of thyroid functions. Higher concentrations of mineral elements in the recruited population were found in this study than other comparable studies, and the levels of chromium (Cr), manganese (Mn), nickel (Ni), arsenic (As), cadmium (Cd), selenium (Se), antimony (Sb), thallium (Tl) and lead (Pb) in the case group were lower than the control group. According to the single-element models, Cr, Mn, Ni, Sb and Tl showed significant negative associations with the risk of thyroid tumor and goiter, and, Cd showed nonmonotonic dose response. Cd and mercury (Hg) showed a nonmonotonic percentage change with T4, while Tl was associated with the increased FT4 in the control group. Therefore, Cd, Hg and Tl may disturb the balance of thyroid function to some extent, and Cr, Mn, Ni, Cd, Sb, and Tl may become potential influencing factors for the risk of thyroid tumor and goiter.

Cellular metabolomics reveals glutamate and pyrimidine metabolism pathway alterations induced by BDE-47 in human neuroblastoma SK-N-SH cells.

Polybrominated diphenyl ethers (PBDEs) as potential neurotoxicants in environment may possess hazards to human health. Previous studies have reported that PBDEs exposure could induce oxidative stress and disturb mitochondrial functions in mammalian cells. However, the toxicological mechanism remains to be clarified. In this work, the neurotoxic effect and underlying mechanism of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) was investigated by using human neuroblastoma SK-N-SH cells as an effective model. A liquid chromatography-mass spectrometry (LC-MS)-based metabolomics approach combined with cell viability assay was applied to elucidate the metabolic perturbations and relevant toxicological pathways upon BDE-47 exposure. Our results shown that the SK-N-SH cell viability decreased in a dose-dependent manner after exposure to BDE-47 at 24 h within the concentration range of 5-250 µM, and an IC50 value of 88.8 µM was obtained. Based on the dose-response curve and cell morphological observation, the 5 and 10 µM BDE-47 doses (equal to IC5 and IC10, respectively) were used for metabolomics study to capture the sensitive metabolic response following BDE-47 exposure. After BDE-47 treatment, nine metabolites were identified as potential biomarkers, and the most disturbed metabolic pathways were mainly involved in alanine, aspartate and glutamate metabolism, glutathione metabolism, tyrosine and phenylalanine metabolism, and pyrimidine metabolism, which imply that metabolic changes related to neurotransmitters, oxidative stress, and nucleotide-mediated signal transduction systems were the sensitive pathways mostly influenced. Our findings reported here may provide potential neurotoxic effect biomarkers and prompt deep understanding of the molecular and metabolic mechanisms triggered by BDE-47 exposure.

Thermal decomposition tandem mass spectrometry for rapid detection of tetrabromobisphenol A bis(allyl ether) in soils.

Rapidly and sensitively determining trace levels of contaminants with poor ionization in complex matrices is a great challenge for mass spectrometry analysis. In this work, a thermal decomposition tandem mass spectrometry (TD-MS/MS) method is developed for fast detecting tetrabromobisphenol A bis(allyl ether) (TBBPA-BAE) in soils. Typically, TBBPA-BAE solution in a capillary is decomposed and ionized under heating, then sprayed into the mass spectrometer for MS analysis. Upon optimization, one high abundant ion of m/z 542.75 from TBBPA-BAE by debromination is detected during heating process. By collision-induced dissociation, the ion is fragmented to release the characteristic ion of m/z 501.72, which is used as the target quantitative ion. Each test can be finished within 3 min. A linear range of 0.1-100 µg L-1, limit of detection (LOD, S/N = 3, n = 9) of 0.015 µg L-1, and relative standard deviation of 8.6% (c = 0.1 µg L-1, n = 5) are achieved. The fast and sensitive performance of the developed method for analyzing TBBPA-BAE in soils presents its great potential for studying trace levels of TBBPA derivative contaminants.

Spatiotemporal variability of polybrominated diphenyl ether concentration in atmospheric fine particles in Shenzhen, China.

Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants for various products and have become ubiquitous pollutants in environmental media. However, little is known about PBDE levels in Shenzhen, a manufacturing center of electronic products. This study aimed to investigate spatiotemporal variability of PBDE concentration in atmospheric fine particles (PM2.5) and to estimate the daily inhalation exposure doses for local residents in Shenzhen, China. A total of 36 samples were collected and 8 PBDE compounds (BDE-28, 47, 99, 100, 153, 154, 183 and 209) were analyzed by isotope dilution high-resolution gas chromatograph/high-resolution mass spectrometer (HRGC/HRMS). Mean concentrations of Σ8PBDEs and BDE-209 in PM2.5 in Shenzhen were 33.47 pg/m3 and 24.75 pg/m3, respectively, which were lower than those for other reported cities from China. The mean concentration of Σ8PBDEs was higher in the winter + spring than that in summer + autumn, and both concentrations of BDE-28 and BDE-47 in PM2.5 were significantly higher in winter + spring than those in summer + autumn. Among the 8 congeners, BDE-209 was predominant, accounting for 73.9% of the Σ8PBDEs concentrations. Traffic area, industrial area, residential area and discharge of electronic industries had significant positive influences on PBDE concentrations in PM2.5. Both vegetation area and water area were significantly negatively correlated with PBDE levels in PM2.5. Significantly negative correlation was also found between PBDE concentrations in PM2.5 and the relative humidity. The ranking of estimated inhalation exposure doses of PBDEs via PM2.5 inhalation were toddlers (1.74 pg/kg b.w./day) > children (1.33 pg/kg b.w./day) > adults (1.26 pg/kg b.w./day) > teenagers (0.64 pg/kg b.w./day), and toddlers had a highest risk to expose to PBDEs by PM2.5. To our knowledge, the present study is the first to reveal the spatiotemporal variability of PBDEs in PM2.5 of Shenzhen, China.

Identification and characterization of a type I interferon induced by cyprinid herpesvirus 2 infection in crucian carp Carassius auratus gibelio.

Crucian carp (Carassius auratus gibelio) is a popular food fish in Asia, and cyprinid herpesvirus 2 (CyHV-2) is the only known viral pathogen for crucian carp. Type I interferon genes are induced up on host cell recognition of viral nucleic acids and well recognized for their crucial roles in providing local or systemic protection against the viruses in various organisms. In a transcriptome analysis to uncover differentially expressed genes in crucian carp in response to CyHV-2 challenge, a partial interferon transcript was identified to be significantly up-regulated in the kidney of infected fish, which was named as crucian carp IFNc (ccIFNc). The complete ORF of ccIFNc was further determined by RACE technique, which spanned over 546 bp and encoded a polypeptide containing 182 amino acids. Phylogenetic analysis revealed that ccIFNc clustered with known type I IFN genes from other aquatic organisms. Quantitative RT-PCR analysis demonstrated that ccIFNc was constitutively expressed in all investigated tissues with a comparably higher expression level in spleen, gill, kidney, and muscle. Following challenge with CyHV-2, the transcriptional levels of ccIFNc were dramatically up-regulated in all of the tested tissues, especially in the spleen and gill with increased folds of 436 and 158, respectively. The intramuscular (i.m.) injection of a eukaryotic expression plasmid encoding ccIFNc (pEGFP-cIFNc) resulted in increased ccIFNc expression and reduced the mortality after the CyHV-2 challenge significantly. In summary, our data suggested that the ccIFNc belongs to the type I interferon family with a potential role in countering CyHV-2 infection in crucian carp.

Molecular characterization and expression analysis of four fish-specific CC chemokine receptors CCR4La, CCR4Lc1, CCR4Lc2 and CCR11 in rainbow trout (Oncorhynchus mykiss).

The chemokine and chemokine receptor networks regulate leukocyte trafficking, inflammation, immune cell differentiation, cancer and other biological processes. Comparative immunological studies have revealed that both chemokines and their receptors have expanded greatly in a species/lineage specific way. Of the 10 human CC chemokine receptors (CCR1-10) that bind CC chemokines, orthologues only to CCR6, 7, 9 and 10 are present in teleost fish. In this study, four fish-specific CCRs, termed as CCR4La, CCR4Lc1, CCR4Lc2 and CCR11, with a close link to human CCR1-5 and 8, in terms of amino acid homology and syntenic conservation, have been identified and characterized in rainbow trout (Oncorhynchus mykiss). These CCRs were found to possess the conserved features of the G protein-linked receptor family, including an extracellular N-terminal, seven TM domains, three extracellular loops and three intracellular loops, and a cytoplasmic carboxyl tail with multiple potential serine/threonine phosphorylation sites. Four cysteine residues known to be involved in forming two disulfide bonds are present in the extracellular domains and a DRY motif is present in the second intracellular loop. Signaling mediated by these receptors might be regulated by N-glycosylation, tyrosine sulfation, S-palmitoylation, a PDZ ligand motif and di-leucine motifs. Studies of intron/exon structure revealed distinct fish-specific CCR gene organization in different fish species/lineages that might contribute to the diversification of the chemokine ligand-receptor networks in different fish lineages. Fish-specific trout CCRs are highly expressed in immune tissues/organs, such as thymus, spleen, head kidney and gills. Their expression can be induced by the pro-inflammatory cytokines, IL-1ß, IL-6 and IFNγ, by the pathogen associated molecular patterns, PolyIC and peptidoglycan, and by bacterial infection. These data suggest that fish-specific CCRs are likely to have an important role in immune regulation in fish.

Identification and expression analysis of two interleukin-23α (p19) isoforms, in rainbow trout Oncorhynchus mykiss and Atlantic salmon Salmo salar.

Interleukin (IL)-23 is a heterodimeric IL-12 family cytokine composed of a p19 α-chain, linked to a p40 ß-chain that is shared with IL-12. IL-23 is distinguished functionally from IL-12 by its ability to induce the production of IL-17, and differentiation of Th17 cells in mammals. Three isoforms of p40 (p40a, p40b and p40c) have been found in some 3R teleosts. Salmonids also possess three p40 isoforms (p40b1, p40b2 and p40c) although p40a is missing, and two copies (paralogues) of p40b are present that have presumably been retained following the 4R duplication in this fish lineage. Teleost p19 has been discovered recently in zebrafish, but to date there is limited information on expression and modulation of this molecule. In this report we have cloned two p19 paralogues (p19a and p19b) in salmonids, suggesting that a salmonid can possess six potential IL-23 isoforms. Whilst Atlantic salmon has two active p19 genes, the rainbow trout p19b gene may have been pseudogenized. The salmonid p19 translations share moderate identities (22.8-29.9%) to zebrafish and mammalian p19 molecules, but their identity was supported by structural features, a conserved 4 exon/3 intron gene organisation, and phylogenetic tree analysis. The active salmonid p19 genes are highly expressed in blood and gonad. Bacterial (Yersinia ruckeri) and viral infection in rainbow trout induces the expression of p19a, suggesting pathogen-specific induction of IL-23 isoforms. Trout p19a expression was also induced by PAMPs (poly IC and peptidoglycan) and the proinflammatory cytokine IL-1ß in primary head kidney macrophages. These data may indicate diverse functional roles of trout IL-23 isoforms in regulating the immune response in fish.

Effect on metabolic enzymes and thyroid receptors induced by BDE-47 by activation the pregnane X receptor in HepG2, a human hepatoma cell line.

2,2',4,4'-Tetra-bromodiphenyl ether (BDE-47), an important congener among polybrominated diphenyl ether (PBDE) compounds, has been predominantly in environmental samples and human tissue. Thyroid disruption is the most sensitive endpoint effect among a number of health effects of exposure to BDE-47 in animals and humans. However, the detailed underlying mechanisms in humans are not well understood. In the present study, human pregnane X receptor (hPXR)-overexpressing HepG2 cell model and a dual-luciferase reporter assay system were constructed to investigate the role of hPXR in BDE-47-induced alterations of expression of metabolic enzymes and TR in vitro. The results showed that hPXR was significantly activated by BDE-47, and expression levels of both mRNA and protein of the thyroid receptor (TR) isoforms TRα1 and TRß1 were decreased in hPXR-overexpressing HepG2 cells after BDE-47 treatment. However, the increased expression of hepatic microsomal phase I enzyme CYP3A4 and phase II enzymes, UGT1A3 and SULT2A1 were also found. Taken together, the results indicated that BDE-47 was a strong hPXR activator, activation of hPXR played an important role in BDE-47-induced down-regulation of TR, and up-regulations of CYP3A4, UGT1A3, and SULT2A1 participated in the process, which may provide more toxicological evidence on mechanisms of disruption of thyroid hormone induced by BDE-47.

Sequence and expression analysis of rainbow trout CXCR2, CXCR3a and CXCR3b aids interpretation of lineage-specific conversion, loss and expansion of these receptors during vertebrate evolution.

The chemokine receptors CXCR1-3 bind to 11 chemokines (CXCL1-11) that are clustered on the same chromosome in mammals but are largely missing in ray-finned fish. A second CXCR1/2, and a CXCR3a and CXCR3b gene have been cloned in rainbow trout. Analysis of CXCR1-R3 genes in lobe-finned fish, ray-finned fish and tetrapod genomes revealed that the teleostomian ancestor likely possessed loci containing both CXCR1 and CXCR2, and CXCR3a and CXCR3b. Based on this synteny analysis the first trout CXCR1/2 gene was renamed CXCR1, and the new gene CXCR2. The CXCR1/R2 locus was shown to have further expanded in ray-finned fish. In relation to CXCR3, mammals appear to have lost CXCR3b and birds both CXCR3a and CXCR3b during evolution. Trout CXCR1-R3 have distinct tissue expression patterns and are differentially modulated by PAMPs, proinflammatory cytokines and infections. They are highly expressed in macrophages and neutrophils, with CXCR1 and CXCR2 also expressed in B-cells.

[Accumulative levels of organochlorine pesticides of HCHs, DDTs in breast milk and risk factors analysis in Shenzhen].

OBJECTIVE: To first investigate the accumulative levels of DDTs and HCHs in human breast milk of primipara in Shenzhen area, analyze influencing factors and assess exposure risk of infant in Shenzhen. METHODS: From April in 2011 to April in 2012, 85 primiparas who have lived in Shenzhen over 3 years after parturition 4 - 6 weeks were recruited, and their breast milk were collected and questionnaires were filled out simultaneously. The samples were extracted five times with hexane, cleaned up by gel permeation chromatograph (GPC) and SPE, and quantified by gas chromatography-election capture detection (GC-ECD). Correlations between DDTs, HCHs and maternal age, weight, dietary, living time as well as infant birth weight and length were also analyzed with the SPSS 13.0 statistical software respectively. RESULTS: Among the several groups of DDTs and HCHs metabolites, p,p'-DDE were detected in total 85 samples and beta-HCH were detected in 58 samples, which accounted for 68.2% of the breast milk. The median levels of sigmaHCHs and sigma DDTs were 2.980 ng/g whole weight (80.200 ng/g fat) and 9.610 ng/g whole weight (268.390 ng/g fat). Both levels of sigmaHCHs and sigmaDDTs in the human milk had a positive association with maternal age among the demographic characteristics of primiparas. Furthermore, levels of sigma HCHs were positively correlated with freshwater fish consumption. However, sigma DDTs levels which were calculated in fat had a positive association only with the amount of poultry meat intake. CONCLUSION: Beta-HCH and p,p'-DDE were detected in human breast milk, and correlated with age and dietary intake. The average estimated daily intakes of HCHs and DDTs by infants are 0.468, 1.842 microg/(kg x BW x d) respectively, lower than acceptable daily intakes (ADI) proposed by the Ministry of Health of China and (the WHO/FAO) Joint Meeting of Pesticide Residues (JMPR). The average levels of HCHs, DDTs in the breast milk in Shenzhen general population are lower than those of Chinese average level.

[Association of hOGG1 genotype with life style and oxidative DNA damage in five ethnic populations in China].

OBJECTIVE: To assess the natural variation of hOGG1 gene and the gene-environmental interactions. METHODS: The hOGG1 codon 326 polymorphism and urinary 8-OHdG levels were investigated in a large sample of healthy individuals (n = 953) from five ethnic populations in China by using PCR-RFLP and HPLC-ECD. Life style parameters were obtained through a questionnaire survey. RESULTS: The allelic frequencies of hOGG1 gene in whole subjects were 0.16 (Ser/Ser), 0.49 (Ser/Cys) and 0.35 (Cys/Cys). The frequency of Ser326Cys was significantly different among the five ethnic populations (P = 0.002). No association was found between the hOGG1 gene polymorphism and other life style parameters except for the association between Ser326Cys and smoking (P = 0.027). A significant increase of urinary 8-OHdG level was observed in Cys326Cys allelic healthy subjects (P = 0.033). CONCLUSION: There are natural variations of hOGG1 gene in different ethnic populations in China. Smoking is related to the frequencies of Cys/Cys polymorphism, and the repairing of oxidative DNA damage is lower in individuals with the hOGG1 Cys326Cys genotype.

[Effects of 2,2',4,4'-tetrabrominated diphenyl ethers on the TRalpha1 and TRbeta1 expression in liver in C57BL/6 mice].

OBJECTIVE: To study the effect of 2,2',4,4'-tetrabrominated diphenyl ethers (BDE-47) on the expression change of TRalpha1, TRbeta1 at both mRNA and protein levels. METHODS: C57BL/6 mice were divided randomly into 4 groups and administrated with corn oil, 0.5, 5 and 50 mg/kg/BW BDE-47 for 4 days through intraperitoneal injection respectively. GAPDH selected as internal standard, real time quantitative RT-PCR and Western blot were employed to detect the mRNA levels and protein of TRalpha1 and TRbeta1 in livers. RESULTS: Compared with the control group, the mRNA levels of TRalpha1 and TRbeta1 were up-regulated in the medium and high BDE-47 dose groups (P < 0.05). The protein level of TRalpha1 significantly up-regulated while TRbeta1 was significantly down-regulated. CONCLUSION: BDE-47 could change the expression of TRalpha1 and TRbeta1 in the mRNA and protein levels in liver.