Inhibition of the hepatic vitamin B12-dependent methionine-salvage pathway by trichloroethylene metabolites accounts for the formic aciduria in the rat
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PROVIDER: PRJNA505919 | ENA |
REPOSITORIES: ENA
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Project description:The industrial solvent trichloroethylene (TCE) produces a marked formic aciduria in male and female F344 rats and in male C57Bl mice following single or multiple dosing. The two major metabolites of TCE formed by cytochromes P450 metabolism also produce formic aciduria. The quantity of formic acid excreted was about 2-fold higher following trichloroacetic acid (TCA) compared to trichloroethanol (TCE-OH) or TCE, at similar doses of 16mg/kg/day for 3 days. Prior treatment of male F344 rats with 1-aminobenzotriazole a cytochrome P450 inhibitor, followed by TCE, completely prevented the formic aciduria but had no effect on formic acid excretion produced by TCA, suggesting TCA is the proximate metabolite producing this response. Metabolism of formic acid is largely controlled by the vitamin B12 –dependent methionine salvage pathway. Transcriptomic analysis on the liver of rats dosed with 16mg/kg/day TCE for three days when compared to control liver showed nine differentially expressed genes, of particular interest was the down regulation of LMBRD1 involved in the conversion of vitamin B12 into one of two molecules, methylcobalamin (CH3Cbl) or S-adenosylcobalamin (AdoCbl). Administration of CH3Cbl or hydroxocobalamin for 3 days to rats given a single dose of TCE, lead to a reduction in formic acid in their urine. Similarly, rats given TCE followed by L-methionine for 3 days excreted less formic acid in their urine. These findings suggest an effect on the vitamin B12 –dependent methionine salvage pathway. This was supported by the finding that hepatic methionine synthase, which converts homocysteine to methionine, was inhibited following three large daily dose of TCE. We propose that TCE metabolites interact with the vitamin B12 -dependent methionine salvage pathway leading to tetrahydrofolate deficiency and increased excretion of formic acid in rat urine.
2020-11-20 | GSE122664 | GEO
Project description:Maintenance of NAD+ levels by mitochondrial complex I, the NAD+ salvage pathway, and other routes is an important factor in of neurodegenerative disease and cancer. Both the production of NAD+ and the metabolic enzymes that require it as a redox cofactor or substrate differ widely in abundance across cell types and conditions. Disruption in the NAD+ supply thus exerts different effects depending on the cellular NAD+ requirements existing in the cell. Pharmacological depletion of NAD+ is actively being pursued in cancer and other diseases but these effects are not fully understood. Here, we combine quantitative proteomics and metabolomics to understand the consequences of disrupting cellular NAD+ levels and find that inhibiting the NAD+ salvage pathway depletes serine biosynthesis from glucose by impeding the NAD+-dependent protein 3-phosphoglycerate dehydrogenase (PHGDH). Importantly, breast cancers that depend on PHGDH are exquisitely sensitive to blocking the NAD+ salvage pathway. PHGDH, and the rate-limiting enzyme of NAD+ salvage are also correlated in public tumor proteome and transcript datasets. These findings are immediately translatable to the pharmacological inhibition of NAMPT in PHGDH-dependent cancers.
2018-08-14 | PXD007790 | Pride
Project description:To examine changes, if any, in the expression of mRNAs in the liver tissue of mice, we have employed whole genome microarray expression profiling as a discovery platform to identify genes responsive to Trichloroethylene (TCE) treatment. In our results, the expression levels of 431 mRNAs were changed after TCE exposure, of which 291 were up-regulated and 140 were down-regulated. Using qPCR, we validated six of the mRNA expression changed genes, viz., Jun, Cdkn1a, Rad51b, Uhrf1, Svil and Ihh.
2014-11-14 | GSE58819 | GEO
Project description:To know if Trichloroethylene (TCE) can induce miRNA expression changes in mouse liver, we use microarray to screen for differentially expressed miRNAs in the liver of mice exposed to TCE at a dose of 1000 mg/kg b.w. for 5days . In our results, nine miRNAs were selected by volcano plot filtering (fold change ≥ 2 and P-value ≤ 0.05), out of which eight were up-regulated and one was down-regulated. The differential expression of miR-182-5p, miR-34a-5p and miR-451a were validated by qPCR.
2016-11-22 | GSE85904 | GEO
Project description:RNAPol2 accounts for tumor cells liability to JQ1
| PRJNA306755 | ENA
Project description:Trichloroethylene (TCE) is a widely used industrial chemical, and a common environmental contaminant. It is a well-known carcinogen in rodents and a probable carcinogen in humans. Studies utilizing panels of mouse inbred strains afford a unique opportunity to understand both metabolic and genetic basis for differences in responses to TCE. We tested the hypothesis that individual and liver-specific toxic effects of TCE are genetically controlled and that the mechanisms of toxicity and susceptibility can be uncovered by exploring responses to TCE using a diverse panel of inbred mouse strains. TCE (2100 mg/kg) or corn oil vehicle were administered by gavage to 6-8 wk old male mice of 15 mouse strains. Serum and liver were collected at 2, 8, and 24 hr post dosing and were analyzed for TCE metabolites, hepatocellular injury and gene expression of liver. TCE metabolism, as evident from the levels of individual oxidative and conjugative metabolites, varied considerably between strains. TCE treatment-specific effect on the liver transcriptome was strongly dependent on the individual’s genetic background. PPAR-mediated molecular networks, consisting of the metabolism genes known to be induced by TCE, represent some of the most pronounced molecular effects of TCE treatment in mouse liver that are dependent on the individual’s genetic background. Conversely, cell death, liver necrosis, and immune mediated response pathways which are affected by TCE treatment in liver are largely genetic background-independent. These studies provide better understanding of the mechanisms of TCE-induced toxicity anchored on metabolism and genotype-phenotype correlations that may define susceptibility or resistance. 16 mouse strains were studied, vehicle control and mice treated by gavage with 2100 mg/kg Trichloroethylene and sacrificed 24 hrs after dosing
2011-02-01 | E-GEOD-24278 | biostudies-arrayexpress
Project description:To examine changes, if any, in the expression of mRNAs in the liver tissue of mice, we have employed whole genome microarray expression profiling as a discovery platform to identify genes responsive to Trichloroethylene (TCE) treatment. In our results, the expression levels of 431 mRNAs were changed after TCE exposure, of which 291 were up-regulated and 140 were down-regulated. Using qPCR, we validated six of the mRNA expression changed genes, viz., Jun, Cdkn1a, Rad51b, Uhrf1, Svil and Ihh. Six B6C3F1 male mice were oral administrated with either corn oil or TCE (dissolved in corn oil, 1000mg/kg b.w per day) for 5 days. The expression changes of mRNAs in TCE exposured mouse liver were screened by whole genome microarray expression profiling and were validated by qPCR.
2014-11-14 | E-GEOD-58819 | biostudies-arrayexpress
Project description:To investigate the GLUT3 salvage-induced transcriptome changes, we performed RNA-seq on the SLC2A3 overexpressed and the empty control OCI-AML3 cell lines treated with 250 µM of vitamin C.
2023-04-25 | GSE216576 | GEO
Project description:Argininosuccinate lyase (ASL) is a key enzyme integral to the hepatic urea cycle which is required for ammonia detoxification, and the citrulline-nitric oxide (NO) cycle for NO production. ASL deficient patients present with argininosuccinic aciduria (ASA), an inherited metabolic disease with hyperammonaemia and a chronic systemic phenotype with neurocognitive impairment and chronic liver disease. ASL deficiency as an inherited model of systemic NO deficiency, shows enhanced nitrosative and oxidative stress. Here, we describe the dysregulation of glutathione biosynthesis and upstream cysteine utilization in ASL-deficient patients and mice using targeted metabolomics and in vivo positron emission tomography (PET) imaging using (S)-4-(3-18F-fluoropropyl)-L-glutamate ([18F]FSPG). Upregulation of cysteine metabolism contrasted with glutathione depletion and down-regulated antioxidant pathways. hASL mRNA encapsulated in lipid nanoparticles corrected and rescued the neonatal and adult Asl-deficient mouse phenotypes, respectively, enhancing ureagenesis and glutathione metabolism and ameliorating chronic liver disease. We further present [18F]FSPG PET as a novel non-invasive diagnostic tool to assess liver disease and therapeutic efficacy in ASA. These findings support clinical translation of mRNA therapy for ASA.
2023-01-31 | GSE222874 | GEO
Project description:To test whether a genomic classifier (GC) predicts development of metastatic disease in patients treated with salvage radiation therapy (SRT) after radical prostatectomy (RP).
2017-04-04 | GSE79915 | GEO