An integrative cellular metabolomic study reveals downregulated tricarboxylic acid cycle and potential biomarkers induced by tetrabromobisphenol A in human lung A549 cells

Decoding gelsenicine-induced neurotoxicity in mice via metabolomics and network toxicology

BACKGROUND

Gelsenicine, the most toxic constituent of Gelsemium elegans Benth., is known for its diverse pharmacological activities alongside potent neurotoxicity, frequently leading to poisoning incidents following mistaken ingestion. However, its molecular mechanisms remain largely unexplored.

PURPOSE

This study aimed to elucidate the key mechanistic network underlying gelsenicine-induced neurotoxicity by employing a comprehensive strategy that integrated metabolomics, network toxicology, molecular docking, and experimental validation.

METHODS

Acute oral toxicity tests were conducted in C57BL/6J mice to assess toxic symptoms, determine the median lethal dose (LD50), and evaluate histopathological changes. Untargeted metabolomics was performed to identify differential metabolites and associated pathways in serum, hippocampus (HIP), and medulla oblongata (MO). Integration of network toxicology pinpointed core targets and pathways, which were further validated through molecular docking and RT-qPCR. A core "compound-target-metabolite-pathway" network involved in gelsenicine-induced neurotoxicity was established.

RESULTS

Gelsenicine exhibited an oral LD50 of approximately 1.82 mg/kg and induced neurotoxic damage in the HIP and MO. Two untargeted metabolomic approaches detected a broad range of metabolites, revealing that gelsenicine markedly altered the metabolic profiles of serum, HIP, and MO. Network toxicology analysis identified 187 key targets associated with gelsenicine neurotoxicity. Integrated analyses with the predicted targets of differential metabolites indicated that gelsenicine primarily interferes with the energy metabolism network centered on the malate-aspartate shuttle (MAS), affecting pathways such as carbon metabolism, amino acid metabolism, TCA cycle, and PPAR signaling pathway. Malate, glutamate, and aspartate were identified as core metabolites and potential biomarkers of gelsenicine poisoning. RT-qPCR validation revealed that gelsenicine interfered with the expression of core targets, including GLUD1, MDH, GOT and ME, all of which exhibited good binding energy with gelsenicine.

CONCLUSION

This study unveiled a novel mechanistic insight into gelsenicine-induced neurotoxicity, demonstrating its capacity to perturb multiple energy metabolism pathways associated with MAS. These findings could enhance the theoretical understanding of gelsenicine's neurotoxic effects and highlight potential applications in clinical diagnosis and forensic identification.

Comprehensive analysis of PEPC gene family in Populus trichocarpa: Characterization, evolutionary insights, and the role of PtPEPC4-PtLTPG14 interaction in carbon metabolism

The phosphoenolpyruvate carboxylase (PEPC) is a crucial enzyme involved in the primary carbon metabolism of plants, catalyzing the conversion of phosphoenolpyruvate (PEP) to oxaloacetate (OAA), a key intermediate in various biosynthetic pathways. In this study, we identified five Populus trichocarpa PEPCs, renamed PtPEPC1-PtPEPC5, which were classified into two subfamilies, PTPC and BTPC, based on phylogenetic analysis. Our analysis revealed significant segmental duplication events during the expansion of PtPEPCs, providing insights into the evolutionary history of these genes in poplar. The syntenic analysis of PEPCs between poplar and other species, such as Arabidopsis and willow, highlighted both the diversification and conservation of these genes across different plant species. Protein interaction networks, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis suggested that PtPEPCs may participate in various metabolic pathways related to carbon flow. Expression analysis under stress conditions, including treatments with abscisic acid (ABA), H2O2, and NaCl, indicated potential roles for PtPEPCs in stress responses. Notably, the interaction between PtPEPC4 and PtLTPG14 appeared to play a crucial role in carbon metabolism, laying the groundwork for comprehending the regulatory mechanisms that govern the distribution of carbon among carbohydrates, proteins, and lipids. This insight may have significant implications for the fields of plant breeding and biotechnology.

Metabolic Reprogramming in Gut Microbiota Exposed to Polystyrene Microplastics

Background: Microplastics (MPs) are small plastic fragments with diameters less than 5 mm in size and are prevalent in everyday essentials and consumables. Large global plastic production has now led to a flooding of MPs in our natural environment. Due to their detrimental impacts on the planet's ecosystems and potentially our health, MPs have emerged as a significant public health concern. In this pilot study, we hypothesize that MPs exposure will negatively affect gut microbiota composition and function, in which metabolic reprogramming plays an important role. Methods: Using in vitro experiments, three bacterial strains (Escherichia coli MG1655, Nissle 1917, and Lactobacillus rhamnosus) were selected to investigate the impacts of MPs exposure. The bacterial strains were individually cultured in an anaerobic chamber and exposed to 1 µm polystyrene MPs at various concentrations (0, 10, 20, 50, 100, and 500 µg/mL) in the culture medium. Results: MPs exposure reduced the growth of all three bacterial strains in a dose-dependent manner. Liquid chromatography mass spectrometry (LC-MS)-based untargeted metabolomics revealed significant differences in multiple metabolic pathways, such as sulfur metabolism and amino sugar and nucleotide sugar metabolism. In addition, we extracted gut microbiota from C57BL/6 mice, and 16S rRNA sequencing results showed a significant upregulation of Lactobacillales and a significant reduction in Erysipelotrichales due to MPs exposure. Furthermore, targeted and untargeted metabolomics corroborated the in vitro results and revealed alterations in microbial tryptophan metabolism and energy producing pathways, such as glycolysis/gluconeogenesis and the pentose phosphate pathway. Conclusions: These findings provide evidence that MPs exposure causes comprehensive changes to healthy gut microbiota, which may also provide insights into the mechanistic effects of MPs exposure in humans.

Molecular mechanisms of tetrabromobisphenol A (TBBPA) toxicity: Insights from various biological systems

Tetrabromobisphenol A (TBBPA) is a ubiquitous brominated flame retardant extensively incorporated into a wide range of products. As its utilization has escalated, its environmental exposure risks have concomitantly increased. The molecular properties of TBBPA allow it to persist in the environment and within organisms. In this review, we comprehensively examine the toxicity of TBBPA across different organ systems and elucidate the underlying molecular mechanisms. We particularly emphasize TBBPA's impact on biological signaling pathways, protein functionality, cellular architecture, and epigenetic regulation, which collectively lead to disruptions in endocrine, hepatic, neurological, reproductive, and other biological systems. The analysis of these toxicological phenomena and their fundamental molecular mechanisms has substantially enhanced our understanding of TBBPA's hazardous characteristics. This review also examines potential avenues for future research, with a focus on uncovering novel molecular mechanisms and assessing the toxicological impacts of TBBPA exposure, particularly in relation to interactions with other environmental contaminants. We propose a greater focus on examining the toxic effects and molecular mechanisms of long-term TBBPA exposure at environmentally relevant concentrations to facilitate more accurate assessments of human health risks.

Unravelling the Significance of Seed Proteomics: Insights into Seed Development, Function, and Agricultural Applications

Seeds are essential for plant reproduction, ensuring species survival and dispersal while adapting to diverse environments throughout a plant's life. Proteomics has emerged as a powerful tool for deciphering the complexities of seed growth, germination, and stress responses. Advanced proteomic technologies enable the analysis of protein changes during germination, dormancy, and ageing, enhancing our understanding of seed lifespan and vitality. Recent studies have revealed detailed insights into metabolic processes and storage protein profiles across various plant species. This knowledge is crucial for improving seed storage, conserving quality, and maintaining viability. Additionally, it contributes to sustainable agriculture by identifying stress-responsive proteins and signalling pathways that can mitigate stress and enhance farming practices. This review highlights significant advancements in seed proteomics over the past decade, discussing critical discoveries related to storage proteins, protein interactions, and proteome modifications due to stress. It illustrates how these insights transform seed biology, boosting productivity, food security, and environmentally friendly practices. The review also identifies existing knowledge gaps and provides direction for future research, underscoring the need for continued interdisciplinary collaboration in this dynamic field.

Mechanisms associated with cuproptosis and implications for ovarian cancer

Ovarian cancer, a profoundly fatal gynecologic neoplasm, exerts a substantial economic strain on nations globally. The formidable challenge of its frequent relapse necessitates the exploration of novel cytotoxic agents, efficacious antineoplastic medications with minimal adverse effects, and strategies to surmount resistance to primary chemotherapeutic agents. These endeavors aim to supplement extant pharmacological interventions and elucidate molecular mechanisms underlying induced cytotoxicity, distinct from conventional therapeutic modalities. Recent scientific research has unveiled a novel form of cellular demise, known as copper-death, which is contingent upon the intracellular concentration of copper. Diverging from conventional mechanisms of cellular demise, copper-death exhibits a pronounced reliance on mitochondrial respiration, particularly the tricarboxylic acid (TCA) cycle. Tumor cells manifest distinctive metabolic profiles and elevated copper levels in comparison to their normal counterparts. The advent of copper-death presents alluring possibilities for targeted therapeutic interventions within the realm of cancer treatment. Hence, the primary objective of this review is to present an overview of the proteins and intricate mechanisms associated with copper-induced cell death, while providing a comprehensive summary of the knowledge acquired regarding potential therapeutic approaches for ovarian cancer. These findings will serve as valuable references to facilitate the advancement of customized therapeutic interventions for ovarian cancer.

Daily Vinegar Ingestion Improves Depression and Enhances Niacin Metabolism in Overweight Adults: A Randomized Controlled Trial

Depressive disorders are the most prevalent mental health conditions in the world. The commonly prescribed antidepressant medications can have serious side effects, and their efficacy varies widely. Thus, simple, effective adjunct therapies are needed. Vinegar, a fermented acetic acid solution, is emerging as a healthful dietary supplement linked to favorable outcomes for blood glucose management, heart disease risk, and adiposity reduction, and a recent report suggests vinegar may improve symptoms of depression. This randomized controlled study examined the 4-week change in scores for the Center for Epidemiological Studies Depression (CES-D) questionnaire and the Patient Health Questionnaire (PHQ-9) in healthy overweight adults ingesting 2.95 g acetic acid (4 tablespoons vinegar) vs. 0.025 g acetic acid (one vinegar pill) daily. A secondary objective explored possible underlying mechanisms using metabolomics analyses. At week 4, mean CES-D scores fell 26% and 5% for VIN and CON participants respectively, a non-significant difference between groups, and mean PHQ-9 scores fell 42% and 18% for VIN and CON participants (p = 0.036). Metabolomics analyses revealed increased nicotinamide concentrations and upregulation of the NAD+ salvage pathway for VIN participants compared to controls, metabolic alterations previously linked to improved mood. Thus, daily vinegar ingestion over four weeks improved self-reported depression symptomology in healthy overweight adults, and enhancements in niacin metabolism may factor into this improvement.

Gut microbiome remodeling and metabolomic profile improves in response to protein pacing with intermittent fasting versus continuous caloric restriction

The gut microbiome (GM) modulates body weight/composition and gastrointestinal functioning; therefore, approaches targeting resident gut microbes have attracted considerable interest. Intermittent fasting (IF) and protein pacing (P) regimens are effective in facilitating weight loss (WL) and enhancing body composition. However, the interrelationships between IF- and P-induced WL and the GM are unknown. The current randomized controlled study describes distinct fecal microbial and plasma metabolomic signatures between combined IF-P (n = 21) versus a heart-healthy, calorie-restricted (CR, n = 20) diet matched for overall energy intake in free-living human participants (women = 27; men = 14) with overweight/obesity for 8 weeks. Gut symptomatology improves and abundance of Christensenellaceae microbes and circulating cytokines and amino acid metabolites favoring fat oxidation increase with IF-P (p < 0.05), whereas metabolites associated with a longevity-related metabolic pathway increase with CR (p < 0.05). Differences indicate GM and metabolomic factors play a role in WL maintenance and body composition. This novel work provides insight into the GM and metabolomic profile of participants following an IF-P or CR diet and highlights important differences in microbial assembly associated with WL and body composition responsiveness. These data may inform future GM-focused precision nutrition recommendations using larger sample sizes of longer duration. Trial registration, March 6, 2020 (ClinicalTrials.gov as NCT04327141), based on a previous randomized intervention trial.

Copper-mediated novel cell death pathway in tumor cells and implications for innovative cancer therapies

Previous investigations have unraveled an array of cellular demise modalities, encompassing apoptosis, necrosis, pyroptosis, iron death, and several others. These diverse pathways of cell death have been harnessed as therapeutic strategies for eradicating tumor cells. Recent scientific inquiries have unveiled a novel mode of cell death, namely copper death, which is contingent upon intracellular copper levels. Diverging from conventional cell death mechanisms, copper death exhibits a heightened reliance on mitochondrial respiration, specifically the tricarboxylic acid (TCA) cycle. Tumor cells exhibit distinctive metabolic profiles and an elevated copper content compared to their normal counterparts. The emergence of copper death presents a tantalizing prospect for targeted therapies in the realm of cancer treatment. Thus, the primary objective of this review is to introduce the proteins and intricate mechanisms underlying copper death, while comprehensively summarizing the extensive body of knowledge concerning its ramifications across diverse tumor types. The insights garnered from this comprehensive synthesis will serve as an invaluable reference for driving the development of tailor-made therapeutic interventions for tumors.

A Review on Tetrabromobisphenol A: Human Biomonitoring, Toxicity, Detection and Treatment in the Environment

Tetrabromobisphenol A (TBBPA) is a known endocrine disruptor employed in a range of consumer products and has been predominantly found in different environments through industrial processes and in human samples. In this review, we aimed to summarize published scientific evidence on human biomonitoring, toxic effects and mode of action of TBBPA in humans. Interestingly, an overview of various pretreatment methods, emerging detection methods, and treatment methods was elucidated. Studies on exposure routes in humans, a combination of detection methods, adsorbent-based treatments and degradation of TBBPA are in the preliminary phase and have several limitations. Therefore, in-depth studies on these subjects should be considered to enhance the accurate body load of non-invasive matrix, external exposure levels, optimal design of combined detection techniques, and degrading technology of TBBPA. Overall, this review will improve the scientific comprehension of TBBPA in humans as well as the environment, and the breakthrough for treating waste products containing TBBPA.

Exploratory analysis of one versus two-day intermittent fasting protocols on the gut microbiome and plasma metabolome in adults with overweight/obesity

Nutritional interventions are a promising therapeutic option for addressing obesity and cardiometabolic dysfunction. One such option, intermittent fasting (IF), has emerged as a viable alternative to daily caloric restriction and may beneficially modulate body weight regulation and alter the gut microbiome (GM) and plasma metabolome. This secondary analysis of a larger, registered trial (ClinicalTrials.gov ID: NCT04327141) examined the effect of a four-week intervention comparing one vs. two-consecutive days of IF in combination with protein pacing (IF-P; 4-5 meals/day, >30% protein/day) on the GM, the plasma metabolome, and associated clinical outcomes in overweight and obese adults. Participants (n = 20) were randomly assigned to either a diet consisting of one fasting day (total of 36 h) and six low-calorie P days per week (IF1-P, n = 10) or two fasting days (60 h total) and five low-calorie P days per week (IF2-P, n = 10). The fecal microbiome, clinical outcomes, and plasma metabolome were analyzed at baseline (week 0) and after four weeks. There were no significant time or interaction effects for alpha diversity; however, baseline alpha diversity was negatively correlated with percent body fat change after the four-week intervention (p = 0.030). In addition, beta-diversity for both IF groups was altered significantly by time (p = 0.001), with no significant differences between groups. The IF1-P group had a significant increase in abundance of Ruminococcaceae Incertae Sedis and Eubacterium fissicatena group (q ≤ 0.007), while the IF2-P group had a significant increase in abundance of Ruminococcaceae Incertae Sedis and a decrease in Eubacterium ventriosum group (q ≤ 0.005). The plasma metabolite profile of IF2-P participants displayed significant increases in serine, trimethylamine oxide (TMAO), levulinic acid, 3-aminobutyric acid, citrate, isocitrate, and glucuronic acid (q ≤ 0.049) compared to IF1-P. Fecal short-chain fatty acid concentrations did not differ significantly by time or between groups (p ≥ 0.126). Interestingly, gastrointestinal symptoms were significantly reduced for the IF2-P group but not for the IF1-P group. Our results demonstrate that short-term IF modestly influenced the GM community structure and the plasma metabolome, suggesting these protocols could be viable for certain nutritional intervention strategies.