1,3-Butadiene (BD) is an important industrial chemical that is classified as a human carcinogen. BD carcinogenicity has been attributed to its metabolism to several reactive epoxide metabolites and formation of the highly mutagenic 1,2:3,4-diepoxybutane (DEB) has been hypothesized to drive mutagenesis and carcinogenesis at exposures experienced in humans. We report herein the formation of DEB-specific N,N-(2,3-dihydroxy-1,4-butadiyl)valine (pyr-Val) in BD-exposed workers as a biomarker of DEB formation. pyr-Val was determined in BD monomer and polymer plant workers that had been previously analyzed for several other biomarkers of exposure and effect. pyr-Val was detected in 68 of 81 (84%) samples ranging from 0.08 to 0.86 pmol/g globin. Surprisingly, pyr-Val was observed in 19 of 23 administrative control subjects not known to be exposed to BD, suggesting exposure from environmental sources of BD. The mean ± SD amounts of pyr-Val were 0.11 ± 0.07, 0.16 ± 0.12, and 0.29 ± 0.20 pmol/g globin in the controls, monomer, and polymer workers, respectively, clearly demonstrating formation of DEB in humans. The amounts of pyr-Val found in this study suggest that humans are much less efficient in the formation of DEB than mice or rats at similar exposures. Formation of pyr-Val was more than 50-fold lower than has been associated with increased mutagenesis in rodents. The results further suggest that formation of DEB relative to other epoxides is significantly different in the highest exposed polymer workers compared with controls and BD monomer workers. Whether this is due to saturation of metabolic formation or increased GST-mediated detoxification could not be determined.
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http://dx.doi.org/10.1093/toxsci/kfr272 | DOI Listing |
Proc Natl Acad Sci U S A
February 2025
Swansea Lab for Animal Movement, Biosciences, College of Science, Swansea University, Swansea, Wales SA2 8PP, United Kingdom.
Large herbivores are in decline in much of the world, including sub-Saharan Africa, and true apex carnivores like the lion () decline in parallel with their prey. As a consequence, competitively subordinate carnivores like the African wild dog () are simultaneously experiencing a costly reduction in resources and a beneficial reduction in dominant competitors. The net effect is not intuitively obvious, but wild dogs' density, survival, and reproduction are all low in areas that are strongly affected by prey depletion.
View Article and Find Full Text PDFClin Cosmet Investig Dermatol
January 2025
Department of Dermatology, Candidate Branch of National Clinical Research Centre for Skin and Immune Diseases, First Affiliated Hospital of Gannan Medical University, Ganzhou, 341000, People's Republic of China.
Dystrophic epidermolysis bullosa (DEB) is a heterogeneous and rare genetic skin disease caused by mutations in the gene, which encodes Type VII collagen. The absence or dysfunction of Type VII collagen can cause the dense lower layer of the basal membrane zone of the skin to separate from the dermis, leading to blister formation and various complications. In different DEB subtypes, the severity of the phenotype is associated, to some extent, with the outcome of Type VII collagen caused by mutations in the gene, which may be reduced in expression, remarkably reduced, or completely absent.
View Article and Find Full Text PDFComput Biol Med
January 2025
National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India. Electronic address:
The biotransformation of drugs by enzymes from the human microbiome can produce active or inactive products, impacting the bioactivity and function of these drugs inside the human host. However, understanding the biotransformation reactions of drug molecules catalyzed by bacterial enzymes in human microbiota is still limited. Hence, to characterize drug utilization capabilities across all the microbial phyla inside the human gut, we have used a knowledge-based approach to develop HgutMgene-Miner software which predicts xenobiotic metabolizing enzymes (XMEs) through genome mining.
View Article and Find Full Text PDFSci Rep
January 2025
Institute of Molecular Biology and Pathology, National Research Council, 00185, Rome, Italy.
Mutations of the MECP2 gene lead to Rett syndrome (RTT), a rare developmental disease causing severe intellectual and physical disability. How the loss or defective function of MeCP2 mediates RTT is still poorly understood. MeCP2 is a global gene expression regulator, acting at transcriptional and post-transcriptional levels.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Soil and Crop Sciences, Colorado State University, Fort Collins, CO, USA.
Current estimates of wetland contributions to the global methane budget carry high uncertainty, particularly in accurately predicting emissions from high methane-emitting wetlands. Microorganisms drive methane cycling, but little is known about their conservation across wetlands. To address this, we integrate 16S rRNA amplicon datasets, metagenomes, metatranscriptomes, and annual methane flux data across 9 wetlands, creating the Multi-Omics for Understanding Climate Change (MUCC) v2.
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