Prenatal exposure to perfluorooctanesulfonate (PFOS) increases fetus' metabolic risk; however, the investigation of the underlying mechanism is limited. In this study, pregnant mice in the gestational days (GD, 4.5-17.5) were exposed to PFOS (0.3 and 3 μg/g of body weight). At GD 17.5, PFOS perturbed maternal lipid metabolism and upregulated metabolism-regulating hepatokines (Angptl4, Angptl8, and Selenop). Mass-spectrometry imaging and whole-genome bisulfite sequencing revealed, respectively, selective PFOS localization and deregulation of gene methylation in fetal livers, involved in inflammation, glucose, and fatty acid metabolism. PCR and Western blot analysis of lipid-laden fetal livers showed activation of AMPK signaling, accompanied by significant increases in the expression of glucose transporters (Glut2/4), hexose-phosphate sensors (Retsat and ChREBP), and the key glycolytic enzyme, pyruvate kinase (Pk) for glucose catabolism. Additionally, PFOS modulated the expression levels of PPARα and PPARγ downstream target genes, which simultaneously stimulated fatty acid oxidation (Cyp4a14, Acot, and Acox) and lipogenesis (Srebp1c, Acaca, and Fasn). Using human normal hepatocyte (MIHA) cells, the underlying mechanism of PFOS-elicited nuclear translocation of ChREBP, associated with a fatty acid synthesizing pathway, was revealed. Our finding implies that in utero PFOS exposure altered the epigenetic landscape associated with dysregulation of fetal liver metabolism, predisposing postnatal susceptibility to metabolic challenges.

Ecology studies showed that esophageal and gastric cancers are directly correlated with the consumption of processed foods. The carcinogenicity of traditional Chinese fermented foods such as douchi (fermented black beans or fermented black soybeans) is due to the presence of carcinogenic N-nitroso compounds, which are derived from biogenic amines. Among the various biogenic amines that can act as precursors of N-nitroso compounds, histamine and tyramine are considered to be the most toxic and are of public health concern when present in food. We have examined some douchi products on the market, and significant amounts of histamine and tyramine were found. The use of fermentation starters generated by subculturing fermented products with unknown microbiota would induce the risk of biogenic amines. As the microbiota used in fermentation is a crucial factor in determining the biogenic amines of fermented food, it is hypothesized that the possible harmful effects of douchi can be minimized through the use of fermentation starters composed of probiotic bacteria. This is the first study to investigate the potential of using probiotic bacteria in manufacturing douchi. Lactobacillus rhamnosus GG (LGG), Lactobacillus casei Shirota (LcS) and Escherichia coli Nissle 1917 (EcN) were used to ferment black beans in this study, and no tyramine was detected in black bean samples incubated with these three strains anaerobically at 37°C or 20°C. The starter culture strains, temperature and presence of oxygen during the incubation period were found to be critical to the generation of biogenic amines. The findings of this study can provide evidence-based insights and warrant further investigations on the potential of reducing the harmful compounds in food fermented with probiotic bacteria as well as the sensory evaluation of douchi fermented with probiotic bacteria.

Understanding the spatiotemporal regulation of specialized metabolism in plants is critical for advancing both basic plant biology and biotechnological applications. PRODUCTION OF ANTHOCYANIN PIGMENT 1 (PAP1) is a well-known transcription factor that plays a key regulatory role in the biosynthesis pathway of plant flavonoids. Similar to other secondary metabolites, flavonoid biosynthesis displays cell heterogeneity. However, the cell-specific regulation network of the flavonoid biosynthetic pathway remains unclear. In this study, we utilized single-cell RNA sequencing (scRNA-seq) and time-series metabolite profiling to investigate the regulation of flavonoid biosynthesis and phytohormone homeostasis in Arabidopsis thaliana by PAP1. By comparing single-cell transcriptomes of the pap1-D mutant and wild-type plant leaves, we constructed a cell-type-specific atlas of gene expression and high-resolution dynamics of metabolites across developmental stages. Our findings reveal that PAP1 overexpression induces distinct spatiotemporal regulation of phenylpropanoid pathway genes in different cell types and widespread upregulation of glycosylation processes. Metabolomic profiling validated these transcriptional patterns and showed significant changes of metabolites in phenylalanine metabolic processes as pap1-D leaf matures. Additionally, PAP1 overexpression leads to significant changes in phytohormone levels, particularly jasmonate and salicylate, indicating complex crosstalk between flavonoid biosynthesis and hormone homeostasis. This integrated multi-omics approach provides unprecedented insights into the cell-specific regulatory networks controlling specialized metabolism and establishes a valuable framework for optimizing metabolic engineering strategies to enhance the production of bioactive plant compounds.

Introduction: Multiple factors can contribute to sub-fecundity, including genetics, lifestyle, and environmental contaminants. PFASs are characterized as “forever chemicals” due to their ubiquitous contamination and their persistence in the environment, wildlife, and humans. Numerous studies have demonstrated that PFAS exposure adversely affects multiple bodily functions, including liver metabolism and gonadal function. It is unclear, however, how the disruption of hepatic fatty acid metabolism affects testicular function.Methods: In this study, male mice were administered 0.3 and 3 μg/g body weight of PFOS for 21 days.Results: Our data showed that PFOS exposure caused hepatic steatosis, as evidenced by significant increases in triglyceride levels, expression of ATP-citrate lyase, and fatty acid synthase, as well as fasting insulin levels. PFOS perturbed the expression levels of hepatokines, of which fibroblast growth factor-21 (Fgf-21), leukocyte cell-derived chemotaxin-2 (Lect-2), and retinol-binding protein-4 (Rbp-4) were significantly reduced, whereas angiopoietin-like 4 (Angptl4) was noticeably increased. While Rbp-4 and Fgf-21 are known to contribute to spermatogenesis and testosterone synthesis. In PFOS-exposed groups, testicular ATP, and testosterone decreased significantly with a significant increase in the expression of peroxisome proliferator-activated receptor-coactivator 1α. Mass spectrophotometry imaging revealed the localization of PFOS in testes, along with significant increases in fatty acid metabolites. These included arachidonic acid, dihomo-α-linolenic acid, dihomo-γ-linolenic acid, oxidized ceramide, diacylglycerol, phosphatidylcholine, and phosphatidylethanolamine, which are associated with inflammation and post-testicular causes of infertility.Discussion: This study revealed potential links between PFOS-elicited changes in hepatic metabolism and their impacts on testicular biology. This study provides insights into alternative targets elicited by PFOS that can be used to develop diagnostic and therapeutic strategies for improving testicular dysfunction.

High-resolution mass spectrometry imaging (MSI) plays a vital role in lipidomics, yet challenges persist in analyzing lipids at the single-cell level due to limitations in spatial resolution and lipid coverage. While existing strategies based on a single matrix application step for dual-polarity provide high lipid coverage from the same sample and enable easy sample preparation, matrix depletion limits their spatial resolution to 10 μm, preventing their application to single-cell imaging. Here, we present a single-cell/subcellular resolution strategy for dual-polarity matrix-assisted laser desorption and ionization mass spectrometry imaging (MALDI-MSI) that eliminates the need for matrix reapplication. This approach achieves 5 μm spatial resolution while maintaining lipid coverage comparable to multistep single-cell imaging methods. This is enabled by a fine-tuned matrix deposition technique that fully utilizes the high sensitivity of N-(1-naphthyl)-ethylenediamine dihydrochloride (NEDC) in dual polarities and optimized acquisition conditions, allowing single-deposition workflows without the need for washing, repreparation, or image recalibration. This single-cell resolution MALDI-MSI strategy successfully imaged a broader range of lipid species with distinctive spatial detail in mouse kidney tissue and lung carcinoma cells (A549). Using spatial probabilistic latent semantic analysis (PLSA), we identified three distinct lipid distribution patterns within a single-cell population in both polarities, and histogram analysis revealed substantial cell-to-cell lipidomic heterogeneity. This strategy overcomes limitations of traditional dual-polarity MSI and provides a powerful tool for advancing cellular lipidomics, elucidating disease mechanisms, and investigating environmental toxicology.