Lactobacillus murinus alleviated lung inflammation induced by PAHs in mice.

OBJECTIVE: This study aimed to investigate the mechanism that Lactobacillus murinus (L. murinus) alleviated lung inflammation induced by polycyclic aromatic hydrocarbons (PAHs) exposure based on metabolomics. METHODS: Female mice were administrated with PAHs mix, L. murinus and indoleacrylic acid (IA) or indolealdehyde (IAId). Microbial diversity in feces was detected by 16 S rRNA gene sequencing. Non-targeted metabolomics analysis in urine samples and targeted analysis of tryptophan metabolites in serum by UPLC-Orbitrap-MS and short-chain fatty acids (SCFA) in feces by GC-MS were performed, respectively. Flow cytometry was used to determine T helper immune cell differentiation in gut and lung tissues. The levels of IgE, IL-4 and IL-17A in the bronchoalveolar lavage fluid (BALF) or serum were detected by ELISA. The expressions of aryl hydrocarbon receptor (Ahr), cytochrome P450 1A1 (Cyp1a1) and forkheadbox protein 3 (Foxp3) genes and the histone deacetylation activity were detected by qPCR and by ELISA in lung tissues, respectively. RESULTS: PAHs exposure induced lung inflammation and microbial composition shifts and tryptophan metabolism disturbance in mice. L. murinus alleviated PAHs-induced lung inflammation and inhibited T helper cell 17 (Th17) cell differentiation and promoted regulatory T cells (Treg) cell differentiation. L. murinus increased the levels of IA and IAId in the serum and regulated Th17/Treg imbalance by activating AhR. Additionally, L. murinus restored PAHs-induced decrease of butyric acid and valeric acid which can reduce the histone deacetylase (HDAC) level in the lung tissues, enhancing the expression of the Foxp3 gene and promoting Treg cell differentiation. CONCLUSION: our study illustrated that L. murinus alleviated PAHs-induced lung inflammation and regulated Th17/Treg cell differentiation by regulating host tryptophan metabolism and SCFA levels. The study provided new insights into the reciprocal influence between gut microbiota, host metabolism and the immune system, suggesting that L. murinus might have the potential as a novel therapeutic strategy for lung diseases caused by environmental pollution in the future.

Inducing somatic cells into pluripotent stem cells is an important platform to study the mechanism of early embryonic development.

The early embryonic development starts with the totipotent zygote upon fertilization of differentiated sperm and egg, which undergoes a range of reprogramming and transformation to acquire pluripotency. Induced pluripotent stem cells (iPSCs), a nonclonal technique to produce stem cells, are originated from differentiated somatic cells via accomplishment of cell reprogramming, which shares common reprogramming process with early embryonic development. iPSCs are attractive in recent years due to the potentially significant applications in disease modeling, potential value in genetic improvement of husbandry animal, regenerative medicine, and drug screening. This review focuses on introducing the research advance of both somatic cell reprogramming and early embryonic development, indicating that the mechanisms of iPSCs also shares common features with that of early embryonic development in several aspects, such as germ cell factors, DNA methylation, histone modification, and/or X chromosome inactivation. As iPSCs can successfully avoid ethical concerns that are naturally present in the embryos and/or embryonic stem cells, the practicality of somatic cell reprogramming (iPSCs) could provide an insightful platform to elucidate the mechanisms underlying the early embryonic development.

A purified membrane protein from Akkermansia muciniphila or the pasteurised bacterium blunts colitis associated tumourigenesis by modulation of CD8+ T cells in mice.

OBJECTIVE: Gut microbiota have been linked to inflammatory bowel disease (IBD) and colorectal cancer (CRC). Akkermansia muciniphila (A. muciniphila) is a gram-negative anaerobic bacterium that is selectively decreased in the faecal microbiota of patients with IBD, but its causative role and molecular mechanism in blunting colitis-associated colorectal cancer (CAC) remain inconclusive. This study investigates how A. muciniphila engages the immune response in CAC. DESIGN: Mice were given dextran sulfate sodium to induce colitis, followed by azoxymethane to establish CAC with or without pasteurised A. muciniphila or a specific outer membrane protein (Amuc_1100) treatment. Faeces from mice and patients with IBD or CRC were collected for 16S rRNA sequencing. The effects of A. muciniphila or Amuc_1100 on the immune response in acute colitis and CAC were investigated. RESULTS: A. muciniphila was significantly reduced in patients with IBD and mice with colitis or CAC. A. muciniphila or Amuc_1100 could improve colitis, with a reduction in infiltrating macrophages and CD8+ cytotoxic T lymphocytes (CTLs) in the colon. Their treatment also decreased CD16/32+ macrophages in the spleen and mesenteric lymph nodes (MLN) of colitis mice. Amuc_1100 elevated PD-1+ CTLs in the spleen. Moreover, A. muciniphila and Amuc_1100 blunted tumourigenesis by expanding CTLs in the colon and MLN. Remarkably, they activated CTLs in the MLN, as indicated by TNF-α induction and PD-1downregulation. Amuc_1100 could stimulate and activate CTLs from splenocytes in CT26 cell conditioned medium. CONCLUSIONS: These data indicate that pasteurised A. muciniphila or Amuc_1100 can blunt colitis and CAC through the modulation of CTLs.

Multiple omics analysis of the protective effects of SFN on estrogen-dependent breast cancer cells.

In recent years, sulforaphane (SFN) has been shown to have antitumor effects. To better understand the molecular basis of SFN intervention in estrogen-dependent breast cancer, integrated multi-omics data analysis was used to provide evidence and insights into molecular biology. MCF-7 breast cancer cells were treated with estradiol (E2) or/and SFN. Genome-wide DNA methylation analysis was performed by using microarray platforms. The protein profile was analyzed by TMT labeled HPLC-MS/MS. The metabolic profile was obtained by GC-MS and UPLC-MS methods. Multivariate statistics analyses, such as PCA and hierarchical clustering, were performed. The Gene Ontology (GO) and KEGG analysis were used to perform enrichment analysis of biological processes and pathways. A set of differentially methylated genes and differentially expressed proteins and metabolites were found, which indicated that SFN may reverse the adverse effects induced by E2. Integrated analysis revealed cancer genes that responded to estrogen and other pathways frequently associated with cancer. Co-pathway analysis revealed that the reversal effects of SFN were associated with purine metabolism and glutathione metabolism. The integrated omics analysis outlined a promising blueprint of the relationship of biological molecules in different dimensions, which will be beneficial for understanding the mechanism of anti-breast cancer effects and for new targets of medicines.

A preliminary study on the homology analysis of clinical Stenotrophomonas maltophilia isolates based on fatty acid profiles.

In order to investigate molecular typing and fatty acid methyl esters (FAMEs) typing of clinical Stenotrophomonas maltophilia (S.maltophilia) isolates based on Random Amplification Polymorphic DNA (RAPD) and Gas Chromatography-Mass Spectrometer (GC-MS) methods, we collected 35 drug-resistant S. maltophilia isolates from March to December 2017 in a comprehensive hospital. The VITEK 2 Compact System was used to determine bacterial antibiotic susceptibility. The analysis of molecular typing was performed by RAPD. GC-MS was used to obtain FAMEs profiles. In total, all 35 isolates were multidrug-resistant S.maltophilia. Their resistance rates to CAZ and LEV were 21.4% and 21.1%, and to SXT up to 13.5%. S. maltophilia isolates were typed to six main clones by RAPD methods and four main clones by FAMEs fingerprint, respectively. The concordance rate of these two methods was 69.0%. Clonal typing provides evidence that multidrug-resistant isolates are prevalent among wards in the hospital. FAMEs profiles may be an easy and sensitive method for bacteria classification. The effectiveness and feasibility of different typing methods should be comprehensively considered.

The Preliminary Study on the Association Between PAHs and Air Pollutants and Microbiota Diversity.

The purpose of this study was to investigate the association among polycyclic aromatic hydrocarbons (PAHs) exposure and air pollutants and the diversity of microbiota. Daily average concentrations of six common air pollutants were obtained from China National Environmental Monitoring Centre. The PAHs exposure levels were evaluated by external and internal exposure detection methods, including monitoring atmospheric PAHs and urinary hydroxyl-polycyclic aromatic hydrocarbon (OH-PAH) metabolite levels. We analyzed the diversity of environmental and commensal bacterial communities with 16S rRNA gene sequencing and performed functional enrichment with Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Correlation analysis and logistic regression modeling were conducted to evaluate the relationship of PAHs levels with air pollutants and microbial diversity. Correlation analysis found that the concentrations of atmospheric PAHs were significantly positively correlated with those of PM10, NO2, and SO2. There also was a positive correlation between the abundance of the genus Micrococcus (Actinobacteria) and high molecular weight PAHs, and Bacillus, such as genera and low molecular weight PAHs in the atmosphere. Logistic regression showed that the level of urinary 1-OHPyrene was associated with childhood asthma after sex and age adjustment. The level of urinary 1-OHPyrene was significantly positively correlated with that of PM2.5 and PM10. In addition, the level of 1-OHPyrene was positively correlated with oral Prevotella-7 abundance. Functional enrichment analysis demonstrated that PAHs exposure may disturb signaling pathways by the imbalance of commensal microbiota, such as purine metabolism, pyrimidine metabolites, lipid metabolism, and one carbon pool by folate, which may contribute to public health issues. Our results confirmed that atmospheric PAHs and urinary 1-OHPyrene were correlated with part of six common air pollutants and indicated that PAHs pollution may alter both environmental and commensal microbiota communities associated with health-related problems. The potential health and environmental impacts of PAHs should be further explored.

Estrogen down regulates COMT transcription via promoter DNA methylation in human breast cancer cells.

Catechol-O-methyltransferase (COMT) acts as a 'gate-keeper' to prevent DNA damage during estrogen metabolism. Both experimental and epidemiological studies suggest the role of COMT in pathogenesis of human breast cancer (BCa). It was previously reported that inhibition of COMT enzyme activity in estradiol-treated human breast epithelial carcinoma-derived MCF-7 cells caused increased oxidative DNA damage and formation of mutagenic depurinating adducts. To improve our understanding of factors influencing estrogen metabolism in BCa, it requires a mechanistic study illustrating the regulation of this 'gate-keeper'. We investigated the epigenetic mechanisms underlying decreased COMT transcription in MCF-7 cells exposed to 17ß-estradiol (E2) and the phytoestrogen, genistein (GEN). CpG site-specific methylation at promoters for both soluble (S) and membrane-bound (MB) COMT transcripts were assessed. Both E2 and GEN induced CpG site-specific methylation within the distal promoter of MB-COMT. In addition, ChIP analysis showed that there was increased binding of DNMT3B, MBD2 and HDAC1 within this promoter. These epigenetic changes were associated with decreased COMT transcript levels. Interestingly, sulforaphane, an antioxidant commonly found in cruciferous vegetables, was able to reverse the estrogen-induced epigenetic changes and gene silencing of COMT. Our data provide a new insight in epigenetically targeting COMT transcription. Since reactive estrogen metabolites may contribute to breast cancer, our findings may help in developing prevention and/or intervention strategies for human BCa.

Improving the selectivity of magnetic graphene oxide through amino modification.

Fabricating efficient materials for environmental purposes is a priority and the subject of much attention nowadays. The objectives of this study are to adopt an amino modification approach to improve the selective removal capacity of magnetic graphene oxide (MGO) for Cu(II) ions, and explore how it performs in single and binary systems by taking Cd(II) as a comparison. After grafting the amino groups, the final material exhibited promoted capacities for Cu(II) and Cd(II), and a more apparent selective adsorption process can be observed. The maximum equilibrium adsorbances of amino modified MGO were 578.1 mg g-1 for Cu(II) and 184.7 mg g-1 for Cd(II) under our experimental conditions, compared with 319.1 mg g-1 and 161.2 mg g-1 of MGO for Cu(II) and Cd(II), respectively. Characterization results and experiment data confirmed that the introduction of N species contributed to the enhancement. This may pave the way for better understanding of the underlying mechanism, and provide inspiration for synthesizing new adsorbents.

The investigation of the role of oral-originated Prevotella-induced inflammation in childhood asthma.

Background and objectives: The oral and gut microbiota play significant roles in childhood asthma pathogenesis. However, the communication dynamics and pathogenic mechanisms by which oral microbiota influence gut microbiota and disease development remain incompletely understood. This study investigated potential mechanisms by which oral-originated gut microbiota, specifically Prevotella genus, may contribute to childhood asthma etiology. Methods: Oral swab and fecal samples from 30 asthmatic children and 30 healthy controls were collected. Microbiome composition was characterized using 16S rRNA gene sequencing and metagenomics. Genetic distances identified potential oral-originated bacteria in asthmatic children. Functional validation assessed pro-inflammatory properties of in silico predicted microbial mimicry peptides from enriched asthma-associated species. Fecal metabolome profiling combined with metagenomic correlations explored links between gut microbiota and metabolism. HBE cells treated with Prevotella bivia culture supernatant were analyzed for lipid pathway impacts using UPLC-MS/MS. Results: Children with asthma exhibited distinct oral and gut microbiota structures. Prevotella bivia, P. disiens, P. oris and Bacteroides fragilis were enriched orally and intestinally in asthmatics, while Streptococcus thermophilus decreased. P. bivia, P. disiens and P. oris in asthmatic gut likely originated orally. Microbial peptides induced inflammatory cytokines from immune cells. Aberrant lipid pathways characterized asthmatic children. P. bivia increased pro-inflammatory and decreased anti-inflammatory lipid metabolites in HBE cells. Conclusion: This study provides evidence of Prevotella transfer from oral to gut microbiota in childhood asthma. Prevotella's microbial mimicry peptides and effects on lipid metabolism contribute to disease pathogenesis by eliciting immune responses. Findings offer mechanistic insights into oral-gut connections in childhood asthma etiology.

Effects of sulforaphane on breast cancer based on metabolome and microbiome.

Sulforaphane (SFN) is a promising phytochemical with a wide range of antitumor activities. A comprehensive understanding of the effects of SFN on breast cancer based on the metabolome and microbiome is limited. Thus, we treated MCF-7 cell-transplanted nude mice with 50 mg/kg SFN. SFN inhibits breast cancer cell proliferation. SFN increased the levels of sulfate-related metabolites and glutathione-related metabolites and decreased tryptophan metabolites and methyl-purine metabolites in urinary metabolic profile. SFN indirectly affected the activation of aryl hydrocarbon receptor by tryptophan metabolism. The ratio of SAM to methionine was decreased by SFN while the global DNA methylation was downregulated in tumor tissue. SFN decreased the sulfate-reducing bacterium Desulfovibrio, which is related to reduced methylation capacity, and increased the genus Lactobacillus related to tryptophan metabolites with antitumor activities. In conclusion, we provide a perspective on the metabolome and microbiome to elucidate the antitumor activities of SFN.

Aerobic exercise inhibits renal EMT by promoting irisin expression in SHR.

To determine the effect of aerobic exercise in different intensities on renal injury and epithelial-mesenchymal transformation (EMT) in the kidney of spontaneously hypertensive rats (SHR) and explore possible mechanisms, we subjected SHR to different levels of 14-week aerobic treadmill training. We tested the effects of aerobic exercise on irisin level, renal function, and EMT modulators in the kidney. We also treated angiotensin II-induced HK-2 cells with irisin and tested the changes in EMT levels. The data showed low and moderate aerobic exercise improved renal function and inhibited EMT through promoting irisin expression in SHR. However, high-intensity exercise training had no effect on renal injury and EMT in SHR but did significantly activate STAT3 phosphorylation in the kidney. These results clarify the mechanisms of exercise in improving hypertension-related renal injury and suggest that irisin might be a therapeutic target for patients with kidney injury.

[Aerobic exercise improves renal fibrosis in spontaneously hypertensive rats].

Objective: To study the effects of aerobic exercise training on renal fibrosis in spontaneously hypertensive rats (SHR), and to explore the protective effect of exercise on renal damage in hypertensive rats. Methods: Eight-week-old male SHR and Wistar Kyoto rats of the same age (WKY) were randomly divided into 4 groups (n=6): sedentary WKY control group (WKY-S), sedentary SHR control group (SHR-S), low-intensity exercise group (SHR-L) and medium-intensity exercise group (SHR-M). SHR-L group and SHR-M group were set at a slope of 0° at 14 m/min (35% of the maximum aerobic speed) and 20 m/min (50% of the maximum aerobic speed), running on a sports treadmill for 14 weeks, 5 times a week, and 60 min each time. WKY-S and SHR-S groups were kept quietly. Blood pressure was measured 72 hours after exercise training. And the serum levels of creatinine (Scr) and BUN were detected. The morphology of renal tissue was observed by hematoxylin and eosin (HE) staining. The collagen deposition of renal tissue was observed by Masson staining, and the renal collagen volume fraction (CVF) was calculated. Results: Compared with WKY-S group, blood pressure, serum Scr and BUN, kidney CVF levels and AngⅡ, AT1R, TGF-ß, α-SMA, CTGF expressions in SHR-S group were increased significantly (P＜0.05). Compared with SHR-S group, blood pressure, serum Scr and BUN, kidney CVF level and AngⅡ, AT1R, TGF-ß, α-SMA, CTGF expressions in SHR-L and SHR-M groups were decreased significantly (P＜0.05) and the decreasing trend was more obvious in SHR-M group (P＜0.05). Conclusion: Aerobic exercise can improve renal fibrosis and renal function in spontaneously hypertensive rats by inhibiting the AngⅡ-AT1R-TGF-ß pathway.

Arabidopsis Circadian Clock Repress Phytochrome a Signaling.

The plants' internal circadian clock can strongly influence phytochrome signaling in response to the changes in the external light environment. Phytochrome A (phyA) is the photoreceptor that mediates various far-red (FR) light responses. phyA signaling is modulated by FHY3 and FAR1, which directly activate the transcription of FHY1 and FHL, whose products are essential for light-induced phyA nuclear accumulation and subsequent light responses. However, the mechanisms by which the clock regulates phyA signaling are poorly understood. Here, we discovered that FHY1 expression is diurnally regulated, peaking in the middle of the day. Two Arabidopsis core clock components, CIRCADIAN CLOCK ASSOCIATED1 (CCA1) and TIMING OF CAB EXPRESSION1 (TOC1), repress FHY3/FAR1-mediated FHY1/FHL activation. Consistently, the specific expression pattern of FHY1 under diurnal conditions is altered in cca1-1, toc1-101, CCA1, and TOC1 overexpression plants. Furthermore, far-red induced gene expression and particularly nuclear accumulation of phyA are compromised in TOC1 and CCA1 overexpression seedlings. Our results therefore revealed a previously unidentified FHY1 expression pattern in diurnal cycles, which is negatively regulated by CCA1 and TOC1.

Aerobic Exercise Training Improves Renal Injury in Spontaneously Hypertensive Rats by Increasing Renalase Expression in Medulla.

We aimed to examine the effects of aerobic exercise training on renal function in spontaneously hypertensive rats (SHR) and elucidate their possible mechanisms. Adult male SHR and age-matched Wistar-Kyoto rats (WKY) were divided into four groups: WKY sedentary group, SHR sedentary group, low-intensity training group, and medium-intensity training group. Using molecular and biochemical approaches, we investigated the effects of 14-week training on renalase (RNLS) protein levels, renal function, and apoptosis and oxidative stress modulators in kidney tissues. In vitro, angiotensin II (Ang II)-induced human kidney proximal epithelial cells (HK-2) were treated with RNLS, and changes in apoptosis and oxidative stress levels were observed. Our results show that moderate training improved renal function decline in SHR. In addition, aerobic exercise therapy significantly increased levels of RNLS in the renal medulla of SHR. We observed in vitro that RNLS significantly inhibited the increase of Ang II-inducedapoptosis and oxidative stress levels in HK-2. In conclusion, aerobic exercise training effectively improved renal function in SHR by promoting RNLS expression in the renal medulla. These results explain the possible mechanism in which exercise improves renal injury in hypertensive patients and suggest RNLS as a novel therapy for kidney injury patients.

Surf4 facilitates reprogramming by activating the cellular response to endoplasmic reticulum stress.

OBJECTIVES: Maternal factors that are enriched in oocytes have attracted great interest as possible key factors in somatic cell reprogramming. We found that surfeit locus protein 4 (Surf4), a maternal factor, can facilitate the generation of induced pluripotent stem cells (iPSCs) previously, but the mechanism remains elusive. MATERIALS AND METHODS: In this study, we investigated the function and mechanism of Surf4 in somatic cell reprogramming using a secondary reprogramming system. Alkaline phosphatase (AP) staining, qPCR and immunofluorescence (IF) staining of expression of related markers were used to evaluate efficiency of iPSCs derived from mouse embryonic fibroblasts. Embryoid body and teratoma formation assays were performed to evaluate the differentiation ability of the iPSC lines. RNA-seq, qPCR and western blot analysis were applied to validate the downstream targets of Surf4. RESULTS: Surf4 can significantly facilitate the generation of iPSCs in a proliferation-independent manner. When co-expressed with Oct4, Sox2, Klf4 and c-Myc (OSKM), Surf4 can activate the response to endoplasmic reticulum (ER) stress at the early stage of reprogramming. We further demonstrated that Hspa5, a major ER chaperone, and the active spliced form of Xbp1 (sXbp1), a major mediator of ER stress, can mimic the effects of Surf4 on somatic cell reprogramming. Concordantly, blocking the unfolded protein response compromises the effect of Surf4 on reprogramming. CONCLUSIONS: Surf4 promotes somatic cell reprogramming by activating the response to ER stress.

Unique Patterns of H3K4me3 and H3K27me3 in 2-Cell-like Embryonic Stem Cells.

A small subgroup of embryonic stem cells (ESCs) exhibit molecular features similar to those of two-cell embryos (2C). However, it remains elusive whether 2C-like cells and 2C embryos share similar epigenetic features. Here, we map the genome-wide profiles of histone H3K4me3 and H3K27me3 in 2C-like cells. We found that the majority of genes in 2C-like cells inherit their histone status from ESCs. Among the genes showing a switch in their histone methylation status during 2C-like transitions, only a small number acquire 2C-embryo epigenetic signatures. In contrast, broad H3K4me3 domains display extensive loss in 2C-like cells. Most of the differentially expressed genes display decreased H3K4me3 and H3K27me3 levels in 2C-like cells, whereas de novo H3K4me3 deposition is closely linked with the expression levels of upregulated 2C-specific genes. Taken together, our study reveals the unique epigenetic profiles of 2C-like cells, facilitating the further exploration of totipotency in the future.

Effects of caffeic acid on epigenetics in the brain of rats with chronic unpredictable mild stress.

The present study hypothesized that caffeic acid (3,4­dihydroxycinnamic acid; CaA) may exert antidepressant­like effects in rats with chronic unpredictable mild stress via epigenetic mechanisms, such as DNA methylation and hydroxymethylation. The chronic unpredictable mild stress (CUMS) model was used to analyze the effects of CaA on behavioral phenotypes, and to evaluate the distribution of 5­methylcytosine (5mC) and 5­hydroxymethylcytosine (5hmC) in the hippocampus and prefrontal cortex using immunohistochemistry and immunofluorescence. mRNA levels of the genes encoding brain­derived neurotropic factor (BDNF) and catechol­O­methyltransferase (COMT), and key enzymes regulating DNA methylation [DNA methyltransferase (DNMT)1 and DNMT3A] and hydroxymethylation [Ten­eleven translocation (TET)1­3] were examined using quantitative (q)PCR. Furthermore, enrichment of 5mC and 5hmC at the promotor regions of the Bdnf and Comt genes was quantified using chromatin immunoprecipitation­qPCR. Behavioral data showed that CaA exerted a slight antidepressant­like effect. Bdnf and Comt genes showed differential expression patterns due to CUMS. CaA intervention induced different Dnmt1/Dnmt3a and Tet1/Tet2 mRNA levels in the hippocampus and prefrontal cortex, respectively. CaA regulated the ratio of 5mC/5hmC at the promotor region of the Bdnf and Comt genes and therefore influenced gene expression, which may be a valuable therapeutic option for major depressive disorder (MDD). In conclusion, there were epigenetic changes in the hippocampus and prefrontal cortex in CUMS rats, and CaA may function as a modulator of DNA methylation to regulate gene transcription, thus providing a mechanistic basis for the use of this phytochemical agent in the treatment of MDD.

Comparative effects of mercury chloride and methylmercury exposure on early neurodevelopment in zebrafish larvae.

Mercury (Hg) is a ubiquitous environmental toxicant with important public health implications. Hg causes neurotoxicity through astrocytes, Ca2+, neurotransmitters, mitochondrial damage, elevations of reactive oxygen species and post-translational modifications. However, the similarities and differences between the neurotoxic mechanisms caused by different chemical forms of Hg remain unclear. Zebrafish embryos were exposed to methylmercury (MeHgCl) or mercury chloride (HgCl2) (0, 4, 40, 400 nM) up for 96 h. HgCl2 exposure could significantly decrease survival rate, body length and eye size, delay the hatching period, induce tail bending and reduce the locomotor activity, and these effects were aggravated in the MeHgCl group. The compounds could increase the number of apoptotic cells in the brain and downregulate the expression of Shha, Ngn1 and Nrd, which contribute to early nervous development. The underlying mechanisms were investigated by metabolomics data. Galactose metabolism, tyrosine metabolism and starch and sucrose metabolism pathways were disturbed after HgCl2 or MeHgCl exposure. In addition, the levels of three neurotransmitters including tyrosine, dopamine and tryptophan were reduced after HgCl2 or MeHgCl exposure. Oxidative stress is related to metabolite changes, such as changes in the putrescine, niacinamide and uric acid contents in the HgCl2 group, and squalene in the MeHgCl group. These data indicated that downregulation of these genes and abnormal metabolic profile and pathways contribute to the neurotoxicity of HgCl2 and MeHgCl.

Sulforaphane-induced metabolomic responses with epigenetic changes in estrogen receptor positive breast cancer cells.

Estrogen is a risk factor for breast cancer. The isothiocyanate sulforaphane (SFN), found in cruciferous vegetables, has been identified as an effective chemopreventive agent, and may prevent or treat breast cancer by reversing estrogen-induced metabolic changes. Here, we investigated metabolic changes in estrogen receptor-positive breast cancer (MCF-7) cells treated with estradiol (E2) and/or SFN to identify key metabolite panels that might provide new insights into the underlying mechanisms of the antitumor effects of SFN. Gas chromatography-mass spectrometry and ultra performance liquid chromatography-mass spectrometry (UPLC-Orbitrap- MS) were used to obtain the metabolic profiles of MCF-7 cells. The data were analyzed using Student's t-test and multivariate statistics, including principal component analysis and partial least squares discriminant analysis. Hydroxymethylation was detected by UPLC-Orbitrap- MS and verified by immunofluorescence assay. We report that significant changes in metabolites induced by E2 and SFN were associated with differences in glycolysis and energy metabolism, and also amino acid, purine, and folic acid metabolism. E2 may alter methylation and hydroxymethylation status via the folic acid pathway. We also identified biomarkers that may be of use in interpretation of the metabolic pathways evoked by the effects of E2 and SFN on breast cancer cells. The identified biomarkers associated with metabolic pathways provide new insight into the chemopreventive mechanisms of SFN.