Tryptophan Biosynthesis Research Articles

An ultra-high-performance liquid chromatography-quadrupole-orbitrap mass spectrometry based metabolomics investigation on pacific oysters (Crassostrea gigas) during depuration and anhydrous living-preservation

Depuration and anhydrous living-preservation are essential steps in the cold chain process for bivalves. However, the mechanisms by which these steps affect the quality of Pacific oysters (Crassostrea gigas) remain inadequately understood. In this study, the metabolic changes in Crassostrea gigas during these processes were investigated. Ultra-high-performance liquid chromatography-quadrupole-Orbitrap mass spectrometry (UHPLC-QE-Orbitrap/MS) was utilized, and multivariate statistical analysis was performed to extract and identify differential metabolites. A comprehensive analysis of the associated metabolic pathways was subsequently conducted, leading to the identification of differential metabolites, including amino acids, organic acids and fatty acids were identified. Among these, 10 key differential metabolites, primarily comprising tyrosine, glutamic acid, glutamine, citrate, succinic acid, arginine, malic acid, L-isoleucine, L-valine and fumaric acid were highlighted. Furthermore, alanine, aspartate and glutamate metabolism, valine, leucine and isoleucine biosynthesis, phenylalanine, tyrosine and tryptophan biosynthesis, tricarboxylic acid (TCA)cycle, nitrogen metabolism and pyruvate metabolism were delineated. These findings reveal the key metabolites and metabolic pathways responsible for quality changes in Pacific oysters during depuration and anhydrous living-preservation. This study provides a theoretical basis for the quality control of Pacific oysters in cold chain circulation, which will help promote the development of the Pacific oyster industry chain.

Metabolome-Wide Mendelian Randomization Assessing the Causal Relationship Between Blood Metabolites and Primary Ovarian Insufficiency

Background & aimsPrimary ovarian insufficiency (POI) is a significant clinical syndrome that leads to female infertility, and its incidence continues to increase. We used metabolome-specific Mendelian randomization (MR) to identify causally associated metabolites and explore the relationship between candidate metabolites and upstream genetic variations. MethodsThe primary MR analysis utilized the inverse variance weighted (IVW) method as the primary approach to assess the causal relationship between exposure and POI. Multiple sensitivity analyses included MR-Egger, weighted median, and weighted mode methods. ResultsAfter using genetic variants as probes, we identified 27 metabolites of 278 that are associated with the risk of POI, including dodecanedioate (OR 0.052, 95% CI 0.010 – 0.265; P < 0.001), adrenate (OR 0.113, 95% CI 0.016 – 0.822; P = 0.031), indolepropionate (OR 0.174, 95% CI 0.051 – 0.593; P = 0.005), homocitrulline (OR 0.194, 95% CI 0.051 – 0.741; P = 0.016), and 3-methylhistidine (OR 0.404, 95% CI 0.193 – 0.848; P = 0.017). Our study indicated the presence of heterogeneity; therefore, we employed the IVW random-effects model as the primary approach. KEGG pathway enrichment analysis identified six significant metabolic pathways, primarily including biosynthesis of unsaturated fatty acids, phenylalanine, tyrosine and tryptophan biosynthesis, aminoacyl-tRNA biosynthesis, linoleic acid metabolism, valine, leucine and isoleucine biosynthesis, ubiquinone and other terpenoid-quinone biosynthesis. ConclusionsBy integrating genomics and metabolomics, this study provides novel insights into the causal relationship linking circulating metabolites and the onset of POI.

Leflunomide-Induced Weight Loss: Involvement of DAHPS Activity and Synthesis of Aromatic Amino Acids.

Background/Objectives: Leflunomide, an isoxazole immunosuppressant, is widely used in the treatment of diseases such as rheumatoid arthritis (RA) and psoriatic arthritis (PsA) as well as lupus nephritis (LN). In recent years, clinical data have shown that some patients have obvious weight loss, liver injury, and other serious adverse reactions after taking leflunomide. However, the causes and mechanisms by which leflunomide reduces weight are unclear. Methods: Therefore, we used a mouse animal model to administer leflunomide, and we observed that the weight of mice in the leflunomide experimental group was significantly reduced (p < 0.01). In this animal experiment, a metabolomic method was used to analyze the livers of the mice in the experimental group and found that the main difference in terms of metabolic pathways was in the metabolism of aromatic amino acids, and it was confirmed that leflunomide can inhibit the limitations of phenylalanine, tyrosine, and tryptophan biosynthesis. Results: Our study revealed that leflunomide inhibited the activity of DAHPS in the gut microbiota, disrupting the metabolism of phenylalanine, tyrosine, and tryptophan, as well as the metabolism of carbohydrates and lipids. Leflunomide also increased endoplasmic reticulum stress by activating the PERK pathway, thereby promoting CHOP expression and increasing apoptosis-induced liver damage. Conclusions: These effects may be related to the observed weight loss induced by leflunomide.

Study on the mechanism of brain injury caused by acute diquat poisoning based on metabolomics

Brain injury following acute diquat poisoning has become increasingly common in moderate to severe cases, with unclear pathogenesis and high mortality. To investigate this, we conducted metabolomics on brain tissue from poisoned rats, combined with clinical biochemical and pathological analyses. In the high-dose group, 24 metabolites showed significant differences compared to the control group: 18 were upregulated, including cytosine, sedoheptulose-7-phosphate, indole, 3-dehydroshikimate, etc.; 6 were downregulated, including 6-phosphogluconic acid, 3-hydroxybenzoic acid, dAMP, etc. In the low-dose group, 10 metabolites showed significant differences: 4 were upregulated, including pentamidine, γ-tocotrienol, benzoylecgonine, etc.; and 6 were downregulated, including dAMP, glutathione, 3-hydroxybenzoic acid, etc. Enrichment analysis identified two key pathways—phenylalanine, tyrosine, and tryptophan biosynthesis, and the pentose phosphate pathway—as involved in brain injury. ROC analysis of six differential metabolites showed that sedoheptulose-7-phosphate, (2R)-2-hydroxy-3-(phosphonatooxy)propanoate, and 3-hydroxybenzoic acid had AUC values above 0.8. These findings suggest that these three metabolites demonstrate strong diagnostic potential for brain injury induced by diquat poisoning. Correlation analysis linked these biomarkers to clinical indicators such as neutrophil count and the eutrophil to lymphocyte ratio, supporting their relevance. This study provides insights into the mechanisms and biomarkers of diquat-induced brain injury, offering a foundation for future treatment and rapid detection.

Integrative network pharmacology and multi-omics to study the potential mechanism of Niuhuang Shangqing Pill on acute pharyngitis

Ethnopharmacological relevanceNiuhuang Shangqing Pill (NSP) is a renowned Chinese medicine prescription listed in the Chinese Pharmacopoeia (Edition, 2020; volume 1) and is utilized in clinical practice for treating headaches and acute pharyngitis (AP) associated with “Shanghuo". Despite its widespread use, the pharmacological mechanism and bioactive components underlying NSP in treating AP remain unclear. Aim of the studyThis study delved into evaluate the alleviation effect of NSP on AP and explore the mechanisms by analyzing multi-omics. Materials and methodsUHPLC-Q Exactive Orbitrap HRMS was employed for the chemical ingredients of NSP. Multiple compositions, targets and pathways involved in the treatment of AP with NSP were predicted by network pharmacology. Additionally, wistar rat model of AP induced by capsaicin was established to evaluate the anti-AP activity of NSP in vivo. The potential mechanism of NSP to improve AP was investigated by real-time PCR, pharyngeal transcriptome analysis, non-targeted metabolomics, immunofluorescence and Western blot. Results119 compounds were identified by UHPLC-Q Exactive Orbitrap HRMS. Both clinical data of Gene Expression Omnibus (GEO) and network pharmacology demonstrated that MAPK signaling pathway and TNF signaling pathway were the critical pathway for AP treatment. In rat model of AP induced by capsaicin, NSP demonstrated the ability to reduce the levels of IL-1β, TNF-α, IL-6, CGRP, SP, PGE2, COX-2 in serum. Moreover, Transcriptomics analysis comprehensively indicated that NSP regulated the MAPK signaling pathway, TNF signaling pathway, biosynthesis of phenylalanine, tyrosine and tryptophan, arachidonic acid metabolism in AP rats. Metabolomics analysis verified that NSP could rebalance arachidonic acid metabolism, biosynthesis of phenylalanine, tyrosine and tryptophan and regulate metabolic profiles. Multi-omics Correlation analysis exhibited that the relative expression of Tnfrsf1b was significantly negatively correlated with 12(S)-HPETE. Immunofluorescence, real-time PCR and Western blot of pharyngeal tissue revealed that NSP inhibited the TNF/p38-MAPK/NF-κB signaling pathway. Additionally, in vitro study on RAW264.7 cells confirmed that NSP counteract LPS-induced inflammatory by inhibiting the TNF/p38-MAPK/NF-κB signaling pathway. Overall, NSP effectively ameliorated capsaicin-induced AP by modulating the arachidonic acid metabolism and TNF/p38-MAPK/NF-κB signaling pathway. ConclusionNSP effectively ameliorated capsaicin-induced AP by modulating the arachidonic acid metabolism, biosynthesis of phenylalanine, tyrosine and tryptophan, as well as the TNF/p38-MAPK/NF-κB signaling pathway.

Metabolomic study for the identification of symptomatic carotid plaque biomarkers

Carotid artery stenosis is mainly produced due to the progressive accumulation of atherosclerotic plaque in the vascular wall. The atherosclerotic plaque is characterized by the accumulation of lipids, low density proteins, expression of chemokines and adhesion molecules, and migration of monocytes and lymphocytes into the plaque. Its rupture can produce stroke, but embolic propensity depends principally on the composition and vulnerability of plaque rather than the severity of stenosis. It is important, then, to ascertain which patients with carotid artery stenosis have a greater risk of developing neurological symptomatology. Here, we present a metabolomic study by using nuclear magnetic resonance (NMR) spectroscopy in atheroma plaque and serum samples from patients with recently symptomatic and asymptomatic carotid stenosis to search for metabolites that could be used as biomarkers associated with plaque vulnerability and subsequent risk of rupture. Thirty-eight atheromatous plaque samples (24 asymptomatic patients and 14 symptomatic) and 70 serum samples (43 asymptomatic and 27 symptomatic) were studied by NMR spectroscopy. The data were analysed using multivariate statistics (PLS-DA) to determine a model to discriminate between symptomatic and asymptomatic samples (atheroma plaques and sera). The calculated PLS-DA models showed a 100 % sensitivity and a 96.6 % specificity for the cross validation to discriminate between symptomatic and asymptomatic plaques, and 88.37 % sensitivity and 77.78 % specificity when serum samples were analysed. According to the results of our multivariate and univariate analysis, the most discriminative metabolites for plaque vulnerability were threonine in serum samples, and glutamate in plaque samples. Also, an analysis of the main metabolic pathways involved in plaque vulnerability revealed that d-glutamine and d-glutamate metabolism, and phenylalanine, tyrosine, and tryptophan biosynthesis were the most affected pathways in plaque and serum, respectively.

Metabolomic Insights into COVID-19 Severity: A Scoping Review.

In 2019, SARS-CoV-2, the novel coronavirus, entered the world scene, presenting a global health crisis with a broad spectrum of clinical manifestations. Recognizing the significance of metabolomics as the omics closest to symptomatology, it has become a useful tool for predicting clinical outcomes. Several metabolomic studies have indicated variations in the metabolome corresponding to different disease severities, highlighting the potential of metabolomics to unravel crucial insights into the pathophysiology of SARS-CoV-2 infection. The PRISMA guidelines were followed for this scoping review. Three major scientific databases were searched: PubMed, the Directory of Open Access Journals (DOAJ), and BioMed Central, from 2020 to 2024. Initially, 2938 articles were identified and vetted with specific inclusion and exclusion criteria. Of these, 42 articles were retrieved for analysis and summary. Metabolites were identified that were repeatedly noted to change with COVID-19 and its severity. Phenylalanine, glucose, and glutamic acid increased with severity, while tryptophan, proline, and glutamine decreased, highlighting their association with COVID-19 severity. Additionally, pathway analysis revealed that phenylalanine, tyrosine and tryptophan biosynthesis, and arginine biosynthesis were the most significantly impacted pathways in COVID-19 severity. COVID-19 severity is intricately linked to significant metabolic alterations that span amino acid metabolism, energy production, immune response modulation, and redox balance.

Gut microbiota and metabolomics unveil the mechanisms of Lomatogonium rotatum in ameliorating visceral fat and serum lipids in high-fat diet-induced obese mice.

Lomatogonium rotatum (LR) is a folk medicinal herb traditionally used as a lipid-lowering and anti-obesity agent; but its pharmacological mechanism is unclear. In this study, we assessed the alterations of LR on gut microbes and serum metabolites in obese mice and their associated mechanisms of modulation on visceral fat and serum lipid by integrating gut microbiota and metabolomics analyses. Mice were fed a high-fat diet (HFD) to generate obesity and were then given LR and Orlistat orally at different doses (0.18, 0.9, 1.8g/kg for LR and 0.048g/kg for Orlistat) for a duration of 9weeks. The impact of LR on weight loss was assessed through the examination of fat deposition, serum lipid indices, liver indices, and HE pathohistology. The effects of LR on gut microbiota and serum metabolites in obese mice were then investigated by 16S rRNA sequencing technology and untargeted metabolomics, and correlation analysis was performed. LR significantly reduced body weight, feed intake, Lee's index, visceral fat accumulation, serum TG, TC, AST and ALT, and elevated serum HDL levels in obese mice. In addition, 16S rRNA sequencing results indicated that the LR intervention remodeled microbial diversity and composition, increased the relative abundance of gut microbes Bacteroidetes and Porphyromonadaceae in HFD-induced obese mice, and decreased the Deferribacteres, Firmicutes and the Firmicutes/Bacteroidetes ratio. Correlation analyses showed that LR regulation of L-tyrosine and hesperetin metabolism, as well as alterations in the metabolic pathways of Phenylalanine, tyrosine and tryptophan biosynthesis, were associated with the changes in abundance of Bacteroidetes, Firmicutes, Porphyromonadaceae and Deferribacteres. Our study demonstrated that LR has lipid lowering and visceral fat reduction effects and its function may be closely related to the improvement of the gut microbiota and its associated metabolites.

Integrative Analysis of Transcriptome and Metabolome Reveals the Regulatory Network Governing Aroma Formation in Grape

The aroma metabolites in grape berries have received attention in recent years, but a global analysis of gene-regulated metabolites is still lacking. In this study, three grape cultivars, “Kyoho”, “Adenauer Rose”, and “Mei Xiangbao”, were used to determine the differential accumulation of metabolites and identify candidate genes related to grape berry aroma. A total of 27,228 genes were detected from the transcriptome, and 128 differentially accumulated metabolites (DAMs) were identified. Terpenoids and ester were the major substances in these three cultivars. KEGG enrichment showed that 12, 8, and 5 compounds were significantly enriched during the maturation process of these three grape cultivars, with most being terpenoids. A combined transcriptome and metabolome analysis found that the associated genes and metabolites were enriched in the following pathways: “Glycine, serine, and threonine metabolism”, “Cysteine and methionine metabolism”, “Tyrosine metabolism”, “Phenylalanine metabolism”, and “Phenylalanine, tyrosine, and tryptophan biosynthesis”. Seven structural genes (VvOMR1, VvGLYK, VvLPD2, VvAK2, VvSHM7, VvASP3, and VvASP1) and four transcription factors (VvERF053, VvERF4, VvMYB46, and VvMYB340) related to grape berry aroma accumulation were discovered. Our findings provide new insights into grape aroma formation and regulatory mechanism research, and the results will be beneficial for grape aroma breeding in the future.

Rewiring the nexus between urban traffic pollution-derived polycyclic aromatic hydrocarbon exposure and DNA injury via urinary metabolomics

Urban road traffic environmental stress impacts outdoor population health, with oxidative damage serving as an early indicator of xenobiotic exposure. Polycyclic aromatic hydrocarbons (PAHs) as priority carcinogens pose significant public health burden, yet knowledge remains limited regarding the endogenous metabolic alternations associated with oxidative DNA injury. This cross-sectional study focused on the cohort consisting of 109 sanitation workers (“traffic exposure group”) and 112 demographics-matched common residents (“controls”) in South China. The goal was to elucidate the occurrence of internal exposure to nine hydroxyl PAHs, and the interrelations with oxidative DNA damage (indicated by 8-hydroxy-2′-deoxyguanosine, 8-OHdG) by linear mixed-effect regression model. T-test and orthogonal partial least squares discriminant analysis were used to determine differential metabolites in non-targeted metabolomics. Results revealed outdoor workers suffered from the heavier PAH exposure burden and exhibited a stronger dose-dependent correlation with 8-OHdG, evidenced by the higher regression coefficient (0.244, 95% CI: 0.154–0.334) than controls (0.203, 95% CI: 0.079–0.328). In total 42 differential endogenous metabolites witnessed significant expression under traffic emission scenario, mainly implicated in phenylalanine, tyrosine and tryptophan biosynthesis. The down-expressed uric acid was the unique metabolite that inversely correlated with the increased intake of ∑8PAH especially in cases. Partially attributed to the traffic-derived PAHs, the dysregulated amino acid, nicotinamide, purine, and steroid hormones metabolic pathways encompassing 11 metabolites were determined as underlying biomarkers in mediating DNA damage. Notably, our findings proposed uric acid may act as a potential antioxidant, as evidenced by the negative correlation with 8-OHdG. The study illustrates outcomes of metabolomics can collaboratively indicate DNA oxidative damage caused by PAHs linked to urban traffic exposure, which holds significant implications for future toxicological research.

Investigating the mechanisms of resveratrol in the treatment of gouty arthritis through the integration of network pharmacology and metabolics.

This study integrates network pharmacology and metabolomics techniques to explore the potential regulatory mechanisms of Res on gouty arthritis (GA). Network pharmacology was used to predict the mechanism of Res in regulating GA, and methods such as HE staining, ELISA, immunohistochemistry, Real-time PCR, Western blot, and molecular docking were used to verify the role of NF-κB, MAPK, and JAK/STAT inflammatory signaling pathways in the MSU-induced GA rat model. In addition, non-targeted metabolomics techniques were combined to further investigate the mechanism of Res in treating GA. The results of network pharmacology showed that Res may exert its therapeutic effects through the NF-κB signaling pathway. Animal experiments demonstrated that in the MSU-induced GA rat model, pathological damage, serum biochemical indicators, and levels of inflammatory factors were significantly increased, and the NF-κB signaling pathway was activated. The intervention of Res significantly reduced pathological damage, serum biochemical indicators, levels of inflammatory factors, and the activation of NF-κB, MAPK, and JAK/STAT signaling pathways in the model rats. Metabolomics results showed that Res could improve the metabolic trajectory deviations in serum and joint fluid of GA model rats. Through related metabolic pathway analysis, the most affected metabolic pathways were found to be Sphingolipid metabolism, Glycerophospholipid metabolism, Phenylalanine, tyrosine and tryptophan biosynthesis, Pantothenate and CoA, Citrate cycle (TCA cycle), and Arachidonic acid metabolism. Resveratrol can regulate the biosynthetic pathways of arachidonic acid, phenylalanine, tyrosine, and tryptophan, pantothenic acid and CoA biosynthesis pathways, TCA cycle, and other metabolic pathways, thereby regulating the NF-κB, MAPK, and JAK/STAT3 signaling pathways, and inhibiting the acute inflammatory response during GA attacks, showing characteristics of multi-pathway and multi-target action.

Wheat bran oil ameliorates high-fat diet-induced obesity in rats with alterations in gut microbiota and liver metabolite profile

BackgroundObesity is one of the public health issues that seriously threatens human health. This study aimed to investigate the effects of wheat bran oil (WBO) on body weight and fat/lipid accumulation in high-fat diet (HFD)-induced obese rats and further explore the possible mechanisms by microbiome and metabolome analyses.MethodsFifty Sprague-Dawley (SD) rats were fed either a normal chow diet (B group, n = 10) or HFD (n = 40) for 14 weeks to establish an obesity model. The HFD-induced obese rats were further divided into four groups and given WBO at 0 mL/kg (M group), 1.25 mL/kg (WBO-L group), 2.5 mL/kg (WBO-M group), and 5 mL/kg (WBO-H group) by oral gavage for 9 weeks. The body weight of rats was weighed weekly. The gut microbiota structure was analyzed using 16 S rDNA high-throughput sequencing. The liver metabolite profile was determined using UHPLC-QE-MS non-target metabolomics technology.ResultsIn this study, WBO treatment reduced body weight gain, fat and lipid accumulation, and ameliorated hepatic steatosis and inflammation. WBO treatment increased the relative abundance of Romboutsia and Allobaculum and decreased that of Candidatus_Saccharimonas, Alloprevotella, Rikenellaceae_RC9_gut_group, Alistipes, Parabacteroides, UCG-005, Helicobacter, Colidextribacter, and Parasutterella compared with the M group. A total of 22 liver metabolites were significantly altered by WBO treatment, which were mainly involved in taurine and hypotaurine metabolism, nicotinate and nicotunamide metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, phenylalanine metabolism, and ether lipid metabolism.ConclusionsWBO alleviated body weight gain and fat/lipid accumulation in HFD-induced obese rats, which may be related to altered gut microbiota and liver metabolites.

Metabolic biomarkers of neonatal sepsis: identification using metabolomics combined with machine learning.

Sepsis is a common disease associated with neonatal and infant mortality, and for diagnosis, blood culture is currently the gold standard method, but it has a low positivity rate and requires more than 2days to develop. Meanwhile, unfortunately, the specific biomarkers for the early and timely diagnosis of sepsis in infants and for the determination of the severity of this disease are lacking in clinical practice. Samples from 18 sepsis infants with comorbidities, 25 sepsis infants without comorbidities, and 25 infants with noninfectious diseases were evaluated using a serum metabolomics approach based on liquid chromatography‒mass spectrometry (LC‒MS) technology. Differentially abundant metabolites were screened via multivariate statistical analysis. In addition, least absolute shrinkage and selection operator (LASSO) and support vector machine recursive feature elimination (SVM-RFE) analyses were conducted to identify the key metabolites in infants with sepsis and without infections. The random forest algorithm was applied to determine key differentially abundant metabolites between sepsis infants with and without comorbidities. Receiver operating characteristic (ROC) curves were generated for biomarker value testing. Finally, a metabolic pathway analysis was conducted to explore the metabolic and signaling pathways associated with the identified differentially abundant metabolites. A total of 189 metabolites exhibited significant differences between infectious infants and noninfectious infants, while 137 distinct metabolites exhibited differences between septic infants with and without comorbidities. After screening for the key differentially abundant metabolites using LASSO and SVM-RFE analyses, hexylamine, psychosine sulfate, LysoPC (18:1 (9Z)/0:0), 2,4,6-tribromophenol, and 25-cinnamoyl-vulgaroside were retained for the diagnosis of infant sepsis. ROC curve analysis revealed that the area under the curve (AUC) was 0.9200 for hexylamine, 0.9749 for psychosine sulfate, 0.9684 for LysoPC (18:1 (9Z)/0:0), 0.7405 for 2,4,6-tribromophenol, 0.8893 for 25-cinnamoyl-vulgaroside, and 1.000 for the combination of all metabolites. When the septic infants with comorbidities were compared to those without comorbidities, four endogenous metabolites with the greatest importance were identified using the random forest algorithm, namely, 12-oxo-20-trihydroxy-leukotriene B4, dihydrovaltrate, PA (8:0/12:0), and 2-heptanethiol. The ROC curve analysis of these four key differentially abundant metabolites revealed that the AUC was 1 for all four metabolites. Pathway analysis indicated that phenylalanine, tyrosine, and tryptophan biosynthesis, phenylalanine metabolism, and porphyrin metabolism play important roles in infant sepsis. Serum metabolite profiles were identified, and machine learning was applied to identify the key differentially abundant metabolites in septic infants with comorbidities, septic infants without comorbidities, and infants without infectious diseases. The findings obtained are expected to facilitate the early diagnosis of sepsis in infants and determine the severity of the disease.

Co-selective effect of dissolved organic matter and chlorine on the bacterial community and their antibiotic resistance in biofilm of drinking water distribution pipes

The proliferation of pathogenic bacteria and antibiotic resistance genes (ARGs) in the biofilm of drinking water distribution pipes poses a serious threat to human health. This work adopted 15 polyethylene (PE) pipes to study the co-selective effect of dissolved organic matter (DOM) and chlorine on the bacterial community and their antibiotic resistance in biofilm. The results indicated that ozone and granular activated carbon (O3-GAC) filtration effectively removed lignins and proteins from DOM, and chlorine disinfection eliminated carbohydrate and unsaturated hydrocarbons, which both contributed to the inhibition of bacterial growth and biofilm formation. After O3-GAC and disinfection treatment, Porphyrobacter, unclassified_d_bacteria, and Sphingopyxis dominated in the biofilm bacterial community. Correspondingly, the bacterial metabolism pathways, including the phosphotransferase system, phenylalanine, tyrosine and tryptophan biosynthesis, ABC transporters, and starch and sucrose metabolism, were downregulated significantly (p < 0.05), compared to the sand filtration treatment. Under such a situation, extracellular polymeric substances (EPS) secretion was inhibited in biofilm after O3-GAC and disinfection treatment, postponing the interaction between EPS protein and pipe surface, preventing bacteria, especially pathogens, from adhering to the pipe surface to form biofilm, and restraining the spread of ARGs. This study revealed the effects of various water filtration and disinfection processes on bacterial growth, metabolism, and biofilm formation on a molecular level, and validated that the O3-GAC filtration followed by chlorine disinfection is an effective and promising pathway to control the microbial risk of drinking water.

Effects of Increasing Oral Deoxynivalenol Gavage on Growth Performance, Blood Biochemistry, Metabolism, Histology, and Microbiome in Rats.

Mycotoxin-contaminated feed or food can affect physiological responses and cause illnesses in humans and animals. In this study, we evaluated the effects of deoxynivalenol (DON) toxicity on the growth performance, blood biochemistry, histology, microbiome, and metabolism of rats fed with different toxin concentrations. After 1 week of acclimatization, seven-week-old male rats received 0.9% saline as a control, 0.02 mg/kg DON as T1, and 0.2 mg/kg DON as T2 via oral gavage for 4 weeks. The final body weight of the T2 group was significantly lower than that of the control and T1; however, the average daily gain, feed intake, and feed conversion ratio did not differ. Fibrosis and apoptosis were observed in various tissues as DON concentration increased. Creatinine and alkaline phosphatase levels were significantly lower in the DON-treated group than in the control. Firmicutes and Desulfobacterota phyla dominated the cecum, whereas those in the feces were Proteobacteria and Bacteroidetes. Metabolomic profiling showed phenylalanine, tyrosine, and tryptophan biosynthesis as the most prominent pathways. Overall, our results suggest that low-dose and short-term DON exposure can trigger several adverse effects in rats. Dietary toxicants in rats may explain the physiological effects associated with the metabolism commonly reported in animals.

Nitidine Chloride Alleviates Hypoxic Stress via PINK1-Parkin-Mediated Mitophagy in the Mammary Epithelial Cells of Milk Buffalo.

Hypoxia in the mammary gland epithelial cells of milk buffalo (BMECs) can affect milk yield and composition, and it can even cause metabolic diseases. Nitidine chloride (NC) is a natural alkaloid with antioxidant properties that can scavenge excessive reactive oxygen species (ROS). However, the effect of NC on the hypoxic injury of BMECs and its molecular mechanisms are still unknown. Here, an immunofluorescence assay, transmission electron microscopy (TEM), and flow cytometry, combined with untargeted metabolomics, were used to investigate the protective effect of NC on hypoxic stress injury in BMECs. It was found that NC can significantly reduce cell activity (p < 0.05) and inhibit cellular oxidative stress (p < 0.05) and cell apoptosis (p < 0.05). A significant decrease in mitophagy mediated by the PINK1-Parkin pathway was observed after NC pretreatment (p < 0.05). In addition, a metabolic pathway enrichment analysis demonstrated that the mechanisms of NC against hypoxic stress may be related to the downregulation of pathways involving aminoacyl tRNA biosynthesis; arginine and proline metabolism; glycine, serine, and threonine metabolism; phenylalanine, tyrosine, and tryptophan biosynthesis; and phenylalanine metabolism. Thus, NC has a protective effect on hypoxic mitochondria, and it can regulate amino acid metabolism in response to hypoxic stress. The present study provides a reference for the application of nitidine chloride to regulate the mammary lactation function of milk buffalo.

Perfluorooctane sulfonate (PFOS) and benzo[a]pyrene (BaP) synergistically induce neurotoxicity in C6 rat glioma cells via the activation of neurotransmitter and Cyp1a1-mediated steroid hormone synthesis pathways

Humans are often exposed to complex mixtures of multiple pollutants rather than a single pollutant. However, the combined toxic effects and the molecular mechanism of PFOS and BaP remain poorly understood. In this study, two typical environmental pollutants, perfluorooctane sulfonate acid (PFOS) and benzo [a]pyrene (BaP), were selected to investigate their combined neurotoxic effects on rat C6 glioma cells at environmentally relevant concentrations. The results showed that coexposure to low-dose PFOS and BaP induced greater toxicity (synergistic effect) than did single exposure. PFOS-BaP coexposure had stronger toxic effects on inducing oxidative stress and promoting early apoptosis. Targeted metabolomics confirmed that increased levels of the neurotransmitters 5-hydroxytryptophan, dopamine, tryptophan and serotonin disturb the phenylalanine, tyrosine and tryptophan biosynthesis pathways. Mechanistically, exposure to a low-dose PFOS-BaP binary mixture induces steroid hormone synthesis disorder through the activation of Cyp1a1 and Hsd17b8 (steroid hormone synthesis genes) and Dhcr24 and Dhcr7 (cholesterol synthesis genes). These findings are useful for comprehensively and systematically elucidating the biological safety of PFOS-BaP and its potential threats to human health.

Manipulating the nucleolar serine-rich protein Srp40p in Saccharomyces cerevisiae may improve isobutanol production.

Isobutanol represents a promising second-generation biofuel. Saccharomyces cerevisiae can produce minor quantities of isobutanol as a byproduct. Increasing yeast tolerance to isobutanol is a crucial step toward achieving higher production levels. Previously, we discovered that expression of the srp40 gene could increase S. cerevisiae isobutanol tolerance. In this study, we explored the impact of overexpressing srp40 on isobutanol production. We used the CEN/ARS plasmid YCplac22-srp40 to overexpress srp40 in S. cerevisiae strain W303-1A. The resulting strain was named W303-1A-srp40. We subsequently performed metabolic engineering of isobutanol synthesis by overexpressing ILV2, ILV3 and ARO10 in W303-1A-srp40. The resulting strain was named 303V2V3A10-22-srp40. Our findings revealed that, compared with the control strain, the 303V2V3A10-22-srp40 strain amplified isobutanol production by 50%. A transcriptome analysis revealed that upregulated genes associated with aminoacyl-tRNA biosynthesis or downregulated genes associated with phenylalanine, tyrosine, and tryptophan biosynthesis might yield increased isobutanol production in 303V2V3A10-22-srp40. Moreover, the decreases in the biosynthesis of amino acids and oxidative phosphorylation might play pivotal roles in the increased isobutanol tolerance of strain W303-1A-srp40. In summary, the overexpression of srp40 could increase isobutanol production and tolerance in S. cerevisiae. This study offers novel insights regarding strategies for increasing isobutanol production.

Enhancing biocontrol efficacy of Cryptococcus laurentii induced by carboxymethyl cellulose: Metabolic pathways and enzyme activities insights

The synergistic biocontrol effects of Cryptococcus laurentii cultured with carboxymethyl cellulose (CMC) were studied to control Penicillium italicum in postharvest grapefruit. The results showed that C. laurentii was cultured in 0.5 % (w/v) CMC (CMC-C. laurentii) significantly inhibited elongation of germ tubes, decreased germination of conidia in P. italicum, and reduced disease in grapefruit. Besides, CMC significantly increased ATP synthase and population proliferation of C. laurentii. Moreover, metabolomics analysis revealed 24 significantly differentially metabolites in CMC-C. laurentii including the citrate cycle, metabolism of glyoxylic acid, dicarboxylic acid, phenylalanine, tyrosine, and tryptophan and amino acid biosynthesis. These results demonstrate that CMC could significantly enhance the ATP synthase by promoting the citrate cycle, providing energy for strain growth, and thereby increasing the biocontrol effectiveness of C. laurentii. Furthermore, adding CMC enhanced the activities of strain extracellular hydrolases and antioxidases, which increased the resistance to stress, thus improving the antagonistic effect of C. laurentii.

Metabolomic profiling of COVID-19 using serum and urine samples in intensive care and medical ward cohorts

The COVID-19 pandemic remains a significant global health threat, with uncertainties persisting regarding the factors determining whether individuals experience mild symptoms, severe conditions, or succumb to the disease. This study presents an NMR metabolomics-based approach, analysing 80 serum and urine samples from COVID-19 patients (34 intensive care patients and 46 hospitalized patients) and 32 from healthy controls. Our research identifies discriminant metabolites and clinical variables relevant to COVID-19 diagnosis and severity. These discriminant metabolites play a role in specific pathways, mainly “Phenylalanine, tyrosine and tryptophan biosynthesis”, “Phenylalanine metabolism”, “Glycerolipid metabolism” and “Arginine and proline metabolism”. We propose a three-metabolite diagnostic panel—comprising isoleucine, TMAO, and glucose—that effectively discriminates COVID-19 patients from healthy individuals, achieving high efficiency. Furthermore, we found an optimal biomarker panel capable of efficiently classify disease severity considering both clinical characteristics (obesity/overweight, dyslipidemia, and lymphocyte count) together with metabolites content (ethanol, TMAO, tyrosine and betaine).