Cysteine Metabolism Research Articles

Low feed intake at weaning reduces intestinal glutathione levels and promotes cysteine oxidation to taurine in pigs

Abstract Weaning stress in pigs is associated with low feed intake and poor nutrient utilization. Cysteine is a sulfur amino acid with key roles in pig production, but how cysteine metabolism and requirements are affected by weaning stress should be better defined. The objective of this study was to determine the collective impact of weaning and feed restriction on tissue cysteine metabolism. Pigs were weaned at 21-d age without access to feed (W; 6.90 ± 0.81 kg; n = 9; reflecting acute nutritional stress) or were not weaned and remained with the sow (NW; 6.81 ± 0.65 kg; n = 8). At euthanasia (23-d age), blood, bile, and liver, jejunum, and ileum tissues were collected. Plasma, bile, and tissue amino acid and amino thiol concentrations were analyzed by HPLC. Activity of glutamate cysteine ligase (GCL) and glutathione synthetase (GSS), enzymes needed for glutathione (GSH) production, and cysteine dioxygenase 1 (CDO1) were determined with activity assays followed by HPLC analysis of reaction products. Plasma (271 versus 192 ± 19 µmol/L; P < 0.001) and liver (417 versus 298 ± 33 nmol/g; P < 0.05) Cys concentrations were increased in W compared to NW pigs. Despite greater plasma Cys, jejunum and ileum Cys content were not affected by weaning (P > 0.10), whereas γ-glutamylcysteine (γ-GlyCys), the immediate precursor of GSH, declined in both jejunum (14.3 versus 9.7 ± 1.4 nmol/g; P < 0.01) and ileum (11.2 versus 6.4 ± 0.8 nmol/g; P < 0.001) in W pigs. Glutathione content was lower in the jejunum (1379 versus 1720 ± 70 nmol/g; P < 0.05) and ileum (1497 versus 1740 ± 74 nmol/g; P < 0.05) in W pigs. In the jejunum, GCL activity tended to be greater (0.56 versus 0.39 ± 0.07 nmol γ-GluCys • mg-1 • min-1; P < 0.10), whereas GSS activity tended to be lower (1.11 versus 1.38 ± 0.10 nmol GSH • mg-1 • min-1; P < 0.10) in W compared to NW pigs. In the ileum, the activities of GCL and GSS were not affected by weaning (P > 0.10). Although liver CDO1 activity was not different between groups (P < 0.10), liver taurine was greater in W compared to NW pigs (5115 versus 2336 ± 912 nmol/g; P = 0.001). Bile concentrations of Cys (1203 versus 279 ± 103 µmol/L; P < 0.001) and cysteinylglycine (203 versus 117 ± 33 µmol/L; P < 0.10), the direct product of GSH degradation, were greater in W compared to NW pigs. Collectively, these results suggest that systemic Cys is not effectively utilized for gut GSH production in newly weaned pigs and is instead oxidized to taurine and eliminated in bile.

Integration of epigenomic and transcriptomic profiling uncovers EZH2 target genes linked to cysteine metabolism in hepatocellular carcinoma

Enhancer of zeste homolog 2 (EZH2), a key protein implicated in various cancers including hepatocellular carcinoma (HCC), is recognized for its association with epigenetic dysregulation and pathogenesis. Despite clinical explorations into EZH2-targeting therapies, the mechanisms underlying its role in gene suppression in HCC have remained largely unexplored. Here, we integrate epigenomic and transcriptomic analyses to uncover the transcriptional landscape modulated by selective EZH2 inhibition in HCC. By reanalyzing transcriptomic data of HCC patients, we demonstrate that EZH2 overexpression correlates with poor patient survival. Treatment with the EZH2 inhibitor tazemetostat restored expression of genes involved in cysteine-methionine metabolism and lipid homeostasis, while suppressing angiogenesis and oxidative stress-related genes. Mechanistically, we demonstrate EZH2-mediated H3K27me3 enrichment at cis-regulatory elements of transsulfuration pathway genes, which is reversed upon inhibition, leading to increased chromatin accessibility. Among 16 EZH2-targeted candidate genes, BHMT and CDO1 were notably correlated with poor HCC prognosis. Tazemetostat treatment of HCC cells increased BHMT and CDO1 expression while reducing levels of ferroptosis markers FSP1, NFS1, and SLC7A11. Functionally, EZH2 inhibition dose-dependently reduced cell viability and increased lipid peroxidation in HCC cells. Our findings reveal a novel epigenetic mechanism controlling lipid peroxidation and ferroptosis susceptibility in HCC, providing a rationale for exploring EZH2-targeted therapies in this malignancy.

Combined Effects of Magnetized Irrigation and Water Source on Italian Lettuce (Lactuca sativa L. var. ramosa Hort.) Growth and Gene Expression

Agricultural water scarcity has become a global issue. Optimizing irrigation water quality and effectively utilizing non-conventional water resources are essential strategies to alleviate pressure on agricultural water use and achieve sustainable development. This study employed Italian lettuce as the test crop to explore the effects of magnetization treatment (M) at a magnetic field strength of 0.2 T and various irrigation water sources (T) on its growth. The following six treatments were established: fresh water irrigation (M0T1), recycled water irrigation (M0T2), saline water irrigation (M0T3), magnetized fresh water irrigation (M1T1), magnetized recycled water irrigation (M1T2), and magnetized saline water irrigation (M1T3). The results showed that the magnetization treatment increased the electrical conductivity (EC), power of hydrogen (pH), and dissolved oxygen (DO) of the three water sources compared to the non-magnetized treatment. Furthermore, magnetized irrigation with fresh water, recycled water, and saline water increased the contents of nitrogen (N), potassium (K), calcium (Ca), and magnesium (Mg) in lettuce. It also led to increases in the contents of soluble proteins (by 9.27% to 22.25%), soluble sugars (by 13.45% to 20.50%), and vitamin C (VitC) (by 4.18% to 19.33%) in lettuce. Additionally, it enhanced the above-ground fresh weight of lettuce (by 9.36% to 8.81%) and water productivity (WPc) (by 5.85% to 10.40%), while reducing water consumption. Among these treatments, magnetized fresh water irrigation was the most effective in improving quality, fresh weight, and WPc, followed by magnetized recycled water. Gene expression analysis revealed that differentially expressed genes (DEGs) were primarily enriched in metabolic pathways such as the MAPK signaling pathway—plant, phytohormone signaling, and cysteine and methionine metabolism. In summary, magnetized irrigation significantly enhanced DO levels in irrigation water, along with the fresh weight, quality, and WPc of lettuce, demonstrating its effectiveness as an efficient method for agricultural irrigation.

Metabolomic profiling of human feces and plasma from extrauterine growth restriction infants.

Extrauterine growth restriction (EUGR) affects a substantial proportion of preterm infants and may influence both short-term complications and long-term sequelae. While many preterm infants with EUGR are secondary to small for gestational age (SGA) or very low birth weight (VLBW), a subset of EUGR infants do not exhibit these conditions. The purpose of this study is to investigate the metabolic profiles and biomarkers of EUGR infants in the absence of SGA and VLBW. A total of 100 feces (n = 50) and plasma samples (n = 50) were collected from participants categorized as either EUGR (EUGR group) or non-EUGR (NonEUGR group) in the absence of SGA and VLBW. Metabolites were characterized via UPLC-MS/MS using the Discovery HD4® platform. Data normalization, partial least squares discriminant analysis (PLSDA), and KEGG enrichment analysis of metabolite profiles were performed using the MetaboAnalyst 6.0. The clinical characteristics of preterm infants differed significantly between the EUGR and NonEUGR groups at discharge, including length of stay, weight Z-score, weight, height Z-score, height, head circumference, and fat-free mass. The PLSDA model exhibited clustering within groups and separation between groups. A total of 58 and 71 differential metabolites were identified in feces and plasma samples, respectively. They were involved in pathways such as caffeine, galactose, glutathione, cysteine, and methionine metabolisms. In the feces sample, 1-palmitoyl-galactosylglycerol exhibited a significant negative correlation with the growth characteristics of preterm infants, while 1-palmitoyl-2-palmitoleoyl-GPC displayed the opposite pattern. In plasma samples, androsterone glucuronide displayed a significant positive correlation with the growth characteristics of preterm infants, whereas 2-methoxyhydroquinone sulfate generated an opposite pattern. Moreover, 2-oleoylglycerol and sphinganine-1-phosphate exhibited the highest area under the curve in feces and plasma samples, respectively, according to diagnostic ROC curves. Preterm infants with EUGR, in the absence of SGA and VLBW, exhibit specific clinical characteristics and metabolomic profiles. Sphinganine-1-phosphate and 2-oleoylglycerol may hold promise as diagnostic markers for EUGR in the absence of SGA and VLBW. The objective of this study is to identify the differential metabolites in preterm infants with extrauterine growth restriction (EUGR) in the absence of small for gestational age (SGA) or very low birth weight (VLBW). Preterm infants with EUGR without SGA and VLBW exhibit specific clinical characteristics and metabolomic profiles. Sphinganine-1-phosphate and 2-oleoylglycerol emerged as potential diagnostic biomarkers for EUGR. This study enhances our understanding of the metabolomic profile in preterm infants with EUGR without SGA or VLBW. Our findings will offer valuable evidence for improving nutritional management and shedding light on the associated pathophysiological mechanisms of EUGR.

Effects of Postharvest SO2 Treatment on Longan Aril Flavor and Glucosinolate Metabolites

SO2 fumigation treatment (commonly known as sulfur treatment, ST) is a key method in the postharvest preservation of imported and exported fresh longan fruits, effectively reducing pericarp browning and enhancing color. Nonetheless, distinctive aromas, often referred to as “sulfur flavor”, may develop in the aril during the extended preservation period. This study employed “Caopu” longan as the test material and patented SO2-releasing paper (ZL201610227848.7) as a treatment to perform a 35-day low-temperature (5 °C) storage of the fruit. The changes in glucosinolates (GSLs) and associated metabolites in the aril of treated fruit (ST) were examined utilizing ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) detection and widely targeted metabolomics technology. The findings indicated that following 35 days of storage, nearly all control (CK) fruit pericarp turned to brown, resulting in an edible fruit rate of 75.41% and a commercial fruit rate of 0%. In contrast, the treated (ST) fruit demonstrated an edible fruit rate and a commercial rate of 99.44%, while the pericarp color changed from dark yellow-brown to light earthy yellow. The sulfur-containing metabolites identified in longan fruit aril predominantly consist of amino acids and their derivatives (60.44%), followed by alkaloids (15.38%), nucleotides and their derivatives (1.10%), and other types (23.08%), which include GSLs. SO2 treatment significantly reduced the content of oxidized glutathione in fruit aril but increased the content of GSLs and related amino acids and their derivatives. Via screening, 19 differential sulfur-containing metabolites were obtained between ST and CK, including 11 GSLs. The identified differential metabolites of GSLs were all increased, primarily comprising aliphatic GSLs, such as 1-hydroxymethyl glucosinolate, 2-Propenyl glucosinolate (Sinigrin), and 4-Methylsulfinylbutyl glucosinolate (Glucoraphanin). Pathway analysis showed that these differential metabolites were mainly involved in coenzyme factor synthesis, cysteine and methionine metabolism, and amino acid synthesis, among other pathways. To the best of our knowledge, this is the first study to reveal the causes of the special flavor of longan aril after SO2 treatment, which is a great concern for longan consumers. Moreover, this study provides a scientific basis for exploring the reasons and mechanisms for the development of the sulfur flavor in the SO2-treated fruits during postharvest storage.

Metabolic Transcriptional Activation in Ulcerative Colitis Identified Through scRNA-seq Analysis

Background: Ulcerative colitis is a chronic inflammatory disease affecting the colon. During chronic inflammation of epithelial cells, lipid metabolism via pro-inflammatory eicosanoids is known to modify the immune response. Methods: Starting from the Mammalian Metabolic Database, the expression of metabolic enzymes was investigated in two independent cohorts from transcriptome datasets GSE38713 and GSE11223, which analyzed ulcerative colitis tissue samples from the digestive tract. Results: In the first cohort, 145 differentially expressed enzymes were identified as significantly regulated between ulcerative colitis tissues and normal controls. Overexpressed enzymes were selected to tune an Elastic Net model in the second cohort. Using the best parameters, the model achieved a prediction accuracy for ulcerative colitis with an area under the curve (AUC) of 0.79. Twenty-two metabolic enzymes were found to be commonly overexpressed in both independent cohorts, with decreasing Elastic Net predictive coefficients as follows: LIPG (3.98), PSAT1 (3.69), PGM3 (2.74), CD38 (2.28), BLVRA (1.99), CBR3 (1.94), NT5DC2 (1.76), PHGDH (1.71), GPX7 (1.58), CASP1 (1.56), ASRGL1 (1.4), SOD3 (1.25), CHST2 (0.965), CHST11 (0.95), KYNU (0.94), PLAG2G7 (0.92), SRM (0.87), PTGS2 (0.80), LPIN1 (0.47), ME1 (0.31), PTGDS (0.14), and ADA (0.13). Functional enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database highlighted the main implications of these enzymes in cysteine and methionine metabolism (adjusted p-value = 0.01), arachidonic acid and prostaglandin metabolism (adjusted p-value = 0.01), and carbon metabolism (adjusted p-value = 0.04). A metabolic score based on the transcriptional activation of the validated twenty-two enzymes was found to be significantly greater in Ulcerative colitis samples compared to healthy donor samples (p-value = 1.52 × 10−8). Conclusions: A metabolic expression score was established and reflects the implications of heterogeneous metabolic pathway deregulations in the digestive tract of patients with ulcerative colitis.

Fungal Methane Production Under High Hydrostatic Pressure in Deep Subseafloor Sediments

Fungi inhabiting deep subseafloor sediments have been shown to possess anaerobic methane (CH4) production capabilities under atmospheric conditions. However, their ability to produce CH4 under in situ conditions with high hydrostatic pressure (HHP) remains unclear. Here, Schizophyllum commune 20R-7-F01, isolated from ~2 km below the seafloor, was cultured in Seawater Medium (SM) in culture bottles fitted with sterile syringes for pressure equilibration. Subsequently, these culture bottles were transferred into 1 L stainless steel pressure vessels at 30 °C for 5 days to simulate in situ HHP and anaerobic environments. Our comprehensive analysis of bioactivity, biomass, and transcriptomics revealed that the S. commune not only survived but significantly enhanced CH4 production, reaching approximately 2.5 times higher levels under 35 MPa HHP compared to 0.1 MPa standard atmospheric pressure. Pathways associated with carbohydrate metabolism, methylation, hydrolase activity, cysteine and methionine metabolism, and oxidoreductase activity were notably activated under HHP. Specifically, key genes involved in fungal anaerobic CH4 synthesis, including methyltransferase mct1 and dehalogenase dh3, were upregulated 7.9- and 12.5-fold, respectively, under HHP. Enhanced CH4 production under HHP was primarily attributed to oxidative stress induced by pressure, supported by intracellular reactive oxygen species (ROS) levels and comparative treatments with cadmium chloride and hydrogen peroxide. These results may provide a strong theoretical basis and practical guidance for future studies on the contribution of fungi to global CH4 flux.

An integrated proteomics and metabolomics analysis of methylglyoxal-induced neurotoxicity in a human neuroblastoma cell line

This study aimed to highlight the molecular and biochemical changes induced by methylglyoxal (MGO) exposure in SH-SY5Y human neuroblastoma cells, and to explore how these changes contribute to its neurotoxicity, utilizing an integrated proteomics and metabolomics approach. Using label-free quantitative nanoLC-MS/MS proteomics and targeted LC-TQ-MS/MS-based metabolomics, the results revealed that MGO exposure, particularly at cytotoxic levels, significantly altered the proteome and metabolome of SH-SY5Y cells. Analysis of proteomics data showed significant alterations in cellular functions including protein synthesis, cellular structural integrity, mitochondrial function, and oxidative stress responses. Analysis of metabolomics and integration of metabolomics and proteomics data highlighted significant changes in key metabolic pathways including arginine biosynthesis, glutathione metabolism, cysteine and methionine metabolism, and the tricarboxylic acid cycle. These results suggest that MGO exposure induced both toxic effects and adaptive responses in cells. MGO exposure led to increased endoplasmic reticulum stress, disruptions in cellular adhesion and extracellular matrix integrity, mitochondrial dysfunction, and amino acid metabolism disruption, contributing to cellular toxicity. Conversely, cells exhibited adaptive responses by upregulating protein synthesis, activating the Nrf2 pathway, and reprogramming metabolism to counteract dicarbonyl stress and maintain energy levels. Furthermore, a set of key proteins and metabolites associated with these changes were shown to exhibit a significant concentration-dependent decrease or increase in their expression levels with increasing MGO concentrations, suggesting their potential as biomarkers for MGO exposure. Taken together, these findings provide insight into the molecular mechanisms underlying MGO-induced neurotoxicity and potential targets for therapeutic intervention.

Analyzing the temporal response mechanisms of the vascular bundles formation of grafted cucumber to different light intensity modes: A joint transcriptomic and metabolomic approach

In plant grafting, the reconnection of vascular bundles between the rootstock and scion not only establishes functional xylem and phloem connections, but also signifies the completion of graft healing. In our previous studies focused on early-stage morphology and physiology of grafted seedlings, we have demonstrated that utilizing light intensities of 50-100-150 μmol/(m2·s) during days 1-3, 4-6, and 7-9 optimizes cucumber/pumpkin graft healing. To further explore the underlying mechanisms, we investigate light intensity regimes: 50-100-100 μmol/(m2·s) and 50-100-150 μmol/(m2·s) during the same time frames (days 1-3, 4-6, and 7-9 after grafting), denoted as CK and T treatments. Initially, we observe histological characteristics of vascular bundle formation under these conditions, followed by the analyses of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), glutathione peroxidase (GSH-Px) enzyme activities, ascorbic acid (AsA) content in the antioxidant system, and the sequencing of transcriptome and metabolome. It is found that grafted seedlings under the T treatment achieve faster vascular bundle reconnection and shorter healing process compared to those under the CK treatment. Enzyme activities (POD, SOD, GSH-Px) increase over time under both light regimes, while CAT activity and AsA content decrease. Notably, by the 9th day, the T treatment (T9d) exhibits higher SOD, POD and CAT activities than the CK treatment (CK9d). Our findings indicate that increasing light intensity during the days 7-9 after grafting can mitigate oxidative damage at the grafting site and benefit vascular bundle reconnection. Transcriptome and metabolome analyses show the up-regulations of Cinnamaldehyde in the phenylpropanoid biosynthesis pathway, the PHGDH gene and L-Homocysteine in the cysteine and methionine metabolism pathway under T treatment in the days 7-9 after grafting. These enhance the antioxidant enzyme activities and reduce the oxidative damage to the grafting site. Additionally, GAE-related genes, and metabolites D-Xylose and Undecaprenyl phosphatealpha-L-Ara4FN in the amino sugar and nucleotide sugar metabolism pathways are also up-regulated under T treatment. The ethylene responsive factor (ERF) transcription factor CsaRAP2.3 positively regulates Undecaprenyl phosphatealpha-L-Ara4FN expression, promoting cell wall synthesis and therefore accelerating vascular bundle reconnection. In summary, during the vascular bundle formation period of cucumber graft healing, both light intensity modes coordinate regulation of phenylpropanoid biosynthesis, cysteine and methionine metabolism, amino sugar and nucleoside sugar metabolism, and ERF transcription factors, promoting graft healing from both stress resistance and cell wall synthesis. Furthermore, building upon the light intensity applied during the callus formation phase, increasing the light intensity during the vascular bundle formation period can significantly enhance cell wall synthesis, thus expediting the graft healing process. Nonetheless, the generalizability of these research findings to other grafting techniques and species requires further investigation.

Coenzyme A biosynthesis in Bacillus subtilis: discovery of a novel precursor metabolite for salvage and its uptake system.

Vitamins are essential components of the diet of animals and humans. Vitamins are thus important targets for biotechnological production. While efficient fermentation processes have been developed for several vitamins, this is not the case for vitamin B5 (pantothenate), the precursor of coenzyme A. We have elucidated the complete pathway for coenzyme A biosynthesis in the biotechnological workhorse Bacillus subtilis. Moreover, a salvage pathway for coenzyme A synthesis was found in this study. Normally, this pathway depends on pantetheine; however, we observed activity of the salvage pathway on complex medium in mutants lacking the pantothenate biosynthesis pathway even in the absence of supplemented pantetheine. This required rewiring of metabolism by expressing a cystine transporter due to acquisition of mutations affecting the regulation of cysteine metabolism. This shows how the hidden "underground metabolism" can give rise to the rapid formation of novel metabolic pathways.

Ascorbic Acid Enhances the Inhibitory Effect of Theasaponins against Candida albicans

Candida albicans (C. albicans) is a main cause of hospital-acquired fungal infections. Combination therapy is promising as a novel anti-C. albicans strategy because of its better efficacy. Theasaponins are pentacyclic triterpenes in the Camellia genus with multiple biological activities. Our previous studies prove that theasaponins display inhibitory activity against C. albicans. Ascorbic acid (VC) is a vitamin found in many plants that shows potential in combination therapy. However, whether VC enhances the activity of theasaponins remains unclear. In this study, the checkerboard micro-dilution method was used to assess the effect of VC (0–80 mmol/L) on the anti-C. albicans effect of theasaponins (0–1000 μg/mL). Then, the effects of theasaponins (31.25 μg/mL), VC (80 mmol/L), and theasaponins (31.25 μg/mL) + VC (80 mmol/L) on C. albicans planktonic cells and different stages of biofilm formation were assessed. Transcriptomic analysis was conducted to investigate the molecular mechanisms. According to the results, VC enhanced the anti-planktonic and anti-biofilm effect of theasaponins against C. albicans. The minimum inhibitory concentration of theasaponins was significantly decreased and the fungicidal efficiency was increased with the addition of VC. VC remarkably aggravated the suppression of theasaponins with regard to various virulence factors of C. albicans, including adhesion, early biofilm formation, mature biofilm, cell surface hydrophobicity, and phospholipase activity. Compared with the theasaponins or VC groups, the level of intracellular reactive oxygen species was higher, while the levels of mitochondrial membrane potential and adenosine triphosphate were lower in the combination group, suggesting more severe oxidative stress, mitochondrial injury, and energy deficiency. Transcriptomic analysis revealed that the combination predominantly suppressed the pathways of glycolysis, glycerophospholipid metabolism, glutathione metabolism, and cysteine and methionine metabolism. This implied that energy deficiency and redox imbalance were associated with the anti-C. albicans activity of the combination. These results prove that VC enhances the inhibitory effect of theasaponins against C. albicans and that the combination has the potential to be used as a topical antifungal therapy or disinfectant.

An integrated metabolomics and proteomics analysis reveals copper‑zinc alloy surface contact-mediated metabolic disruption, lipid peroxidation, and osmotic imbalance of Cryptocaryon irritans tomonts

Cryptocaryon irritans cause massive losses in the mariculture industry and are among the most threatening pathogens affecting teleost species. Copper‑zinc alloy (CZA) surface contact effectively kills C. irritans within minutes. Thus, this study employed integrated metabolomics and proteomics analysis to investigate the killing mechanism of CZA against C. irritans. Moreover, malondialdehyde contents, CuZn-SOD, and ATPase activities were evaluated. Proteomics analysis identified 142 differentially expressed proteins (DEPs), including 91 (59 upregulated, 32 downregulated), 92 (42 upregulated, 50 downregulated), and 43 (17 upregulated, 26 downregulated) DEPs at 0.5 h, 1 h, and 0.5 h vs 1 h of contact treatment with the CZA surface, respectively. Similarly, the metabolomic analysis identified 377 differentially expressed metabolites (DEMs). There were 237 (94 upregulated, 143 downregulated), 264 (112 upregulated, 152 downregulated), and 193 (101 upregulated, 92 downregulated) DEMs at 0.5 h, 1 h, and 0.5 h vs 1 h of contact treatment with the CZA surface, respectively. KEGG-based integrative analyses revealed that CZA exposure significantly enriched proteins and metabolites involved in oxidative phosphorylation, purine, pyrimidine, cysteine, and methionine metabolism. Notably, CZA exposure inhibited the TCA cycle, disrupting energy metabolism, as evidenced by downregulation of key TCA proteins, including citrate synthase and malate dehydrogenase, and metabolites like succinic and malic acids at both 0.5 h and 1 h of CZA treatment. Prolonged CZA exposure also affected protein metabolism, with significant downregulation of ribosomal protein S3a (RPS3a) and proteasome activity. Additionally, CZA surface contact downregulated key proteins involved in pyrimidine (DHFR-TS), purine (RRM1), and cysteine and methionine metabolism (AHCY), leading to disturbances in the methionine cycle, suppression of glutathione metabolism, and alterations in cellular redox status. Quantitative polymerase chain reaction (qPCR) analysis confirmed the upregulation of citrate synthase, proteasome subunit alpha type, and adenosylhomocysteinase with prolonged CZA exposure. Additionally, extended CZA exposure significantly decreased the MDA content due to the increased CuZn-SOD activity. Moreover, CZA exposure reduced Ca2+/Mg2+-ATPase and Na+/K+-ATPase activities. Altogether, CZA surface contact caused metabolic disruption, lipid peroxidation, and osmotic imbalance of C. irritans tomonts, highlighting the broad molecular impact of CZA on cellular processes.

Quercetin supplementation improved the growth and health of juvenile Chinese mitten crabs (Eriocheir sinensis) fed low-fishmeal diets

The substitution of fishmeal with plant proteins can induce oxidative stress in aquatic animals and impair their growth and health. Quercetin is a potent natural antioxidant, but its specific effects on the growth and health of Chinese mitten crabs, as well as the underlying molecular mechanisms, remain unclear. This study aimed to investigate the impact of quercetin on the growth, physiological and biochemical parameters, gut microbiota, and transcriptome of juvenile Chinese mitten crabs (Eriocheir sinensis). Crabs (0.53 ± 0.01 g) were randomly divided into seven groups. One group was fed a diet containing normal fishmeal (35 % fishmeal), whereas the other six groups were fed diets containing low levels of fishmeal (15 % fishmeal) supplemented with different levels of quercetin (0, 250, 500, 1000, 2000, or 4000 mg/kg). Each group had four replicate tanks with 40 crabs per 300 L tank, and the experiment lasted for 56 days. The growth performance of the 35 % fishmeal group was significantly greater than that of the 15 % fishmeal group without quercetin. However, quercetin significantly increased the weight gain rate and specific growth rate of juvenile crabs, especially in the 1000 mg/kg quercetin group, where these rates exceeded those of the normal fishmeal group. The antioxidant capacity and immunity of the 35 % fishmeal group were significantly greater than those of the 15 % fishmeal group. However, quercetin supplementation promoted the antioxidant capacity and immunity of the crabs. Quercetin supplementation at 4000 mg/kg changed the gut microbiota structure by decreasing beneficial bacteria and increasing pathogenic bacteria. Quercetin supplementation enhanced the growth performance and antioxidant capacity of Chinese mitten crabs by increasing glutamate metabolism, pantothenic acid and Coenzyme A biosynthesis, sphingolipid metabolism, arachidonic acid metabolism, and cysteine and methionine metabolism. This study revealedthat dietary supplementation with quercetin can promote Chinese mitten crab growth, antioxidant capacity, and nonspecific immunity; improve gut morphology; and promote gut microbiota homeostasis. The optimal dietary concentration of 688–695 mg/kg is recommended on the basis of weight gain and specific growth rate analyses.

The Effect of Drugs on the Intestinal Microbiota in Crohn's Disease.

We took advantage of a single-center cross-sectional study to investigate the effect of different drugs on intestinal microbiota and function in Crohn's disease. We studied the difference in fecal microbiota of Crohn's disease patients treated with mesalazine, azathioprine, and infliximab, as well as untreated patients, by metagenome and screened for differential microbiota. Further, we investigated functional differences in intestinal microbiota among the four groups. Through metagenomic sequencing, we found that there was no difference between the four groups in ACE and Chao1 indices, but IFX and mesalazine improved species diversity and homogeneity compared to the untreated group, as evidenced by statistically significant differences in the Shannon index, Simpson index, and pielou_evenness. In addition, beta diversity suggested a difference between groups, but the difference was not significant. Non-parametric tests revealed differences between the four groups at the phylum level, class level, and genus level. Further analysis by LEfSe analysis revealed that the level of short-chain fatty acid-producing microbiota was increased in the treated groups, while there was no difference between the treated groups when compared to each other. Finally, the KEGG database and EggNOG database revealed that there were functional differences in intestinal microbiota among the four groups, including microbial metabolism pathway, cysteine and methionine metabolism pathway, cytoskeleton, etc. Conclusions: Mesalazine, azathioprine, and infliximab can all affect the intestinal microbiota and function in patients with Crohn's disease, and the drugs may alleviate intestinal inflammation in patients with Crohn's disease by modulating the intestinal microbiota.

Lycium barbarum arabinogalactan inhibits Escherichia coli and improves Lactobacillus plantarum growth in a defined microbial model of human gut microbiome

Arabinogalactan from Lycium barbarum (LBP-3) is the major biological activity component and contributes to maintaining intestinal immune homeostasis by targeting gut microbiota and their metabolites. However, it is still a big challenge to know the specific ecological microbe-metabolite interaction regulated by LBP-3 due to the host complex diet webs and lots of unidentified intestinal bacteria. Therefore, the present study constructed a defined microbial consortium, composing of symbiotic Bacteroides caccae, Phocaeicola vulgatus, B. thetaiotaomicron, B. uniformis, B. ovatus, Lactobacillus plantarum and Escherichia coli in vitro, to investigate the impact of LBP-3 on the interactions of species and their metabolites. The utilization of LBP-3 by the defined microbial consortium of 7 intestinal species was 22.5%. Full-length 16S rRNA analysis demonstrated that LBP-3 significantly modulated the composition of synthetic bacterial community, especially inhibiting the level of opportunistic pathogenic E. coli and improving the relative abundance of probiotic L. plantarum and all Bacteroidetes species except B. ovatus. LBP-3 remarkedly influenced 27 differential metabolites, mainly belong to amino acids, peptides and analogues (37.04%) and carboxylic acid and derivatives (7.41%). Moreover, targeted metabolomics revealed that the levels of acetate, propionate, tryptophan and 5-methylthioadenosine were improved by LBP-3. In addition, LBP-3 modulated the pathways of tryptophan metabolism, cysteine and methionine metabolism, and biosynthesis of siderophore group nonribosomal peptides. Notably, some amino acids (e.g., proline and glutamate) and their related metabolic pathways (e.g., arginine and proline metabolism) altered by LBP-3 were significantly correlated with the levels of species, such as B. uniformis, P. vulgatus, and B. thetaiotaomicron.

Endocytic pathways and metabolic fate of colloidal bismuth subcitrate in human renal cells

Bismuth compounds, particularly colloidal bismuth subcitrate (CBS), have been widely used in the treatment of gastrointestinal diseases. However, overdose of CBS has been linked to cases of acute renal failure, primarily due to the intracellular accumulation of bismuth in the kidney. To date, the detailed mechanisms of CBS internalization and its metabolic fate remain unclear. In this study, CBS was characterized as a type of nano-object using transmission electron microscopy and dynamic light scattering. Renal cells internalized CBS primarily via clathrin-mediated endocytosis in an active transport manner. Gene knockdown techniques revealed that CBS binds to the transferrin receptor likely through complexing with transferrin before cellular uptake. Once internalized, CBS was sorted into early endosomes, late endosomes, and lysosomes, mediated by microtubules and the Golgi apparatus. Additionally, differentially expressed genes analysis revealed that CBS endocytosis stimulated oxidative stress, significantly affecting the metabolism of glutathione and cysteine within cells. This led to the formation of black bismuth sulfide particles as a result of CBS conjugating with intracellular glutathione. These findings provide crucial insights into the cellular mechanisms underlying excessive CBS exposure, which is essential for understanding and potentially mitigating the risks associated with the use of bismuth compounds in medical treatments.

Revealing the mechanism of Gualou-Xiebai against myocardial ischemia based on network pharmacology and energy metabolism strategies.

Trichosanthes kirilowii-Allium macrostemon (Chinese name Gualou and Xiebai, GLXB), a classical herb pair, has significant clinical efficacy in the treatment of myocardial ischemia (MI). In this study, network pharmacology combined with RNA-seq strategy was employed to predict the targets and pathways of GLXB for MI. GLXB significantly modulated signaling pathways related to the pathology of MI, such as anti-inflammatory and anti-apoptotic signaling pathways such as WNT, PI3K/AKT, and AMPK. GSEA showed that GLXB administration downregulated these key pathways. In addition, Metabolomic analysis demonstrated that GLXB treatment reversed metabolic disorder. Integrative analysis demonstrated three key metabolites (pyruvate, lactate, and palmitate) and three differential genes (Pck1, Cdo1, and Cth) that affected glycolysis or gluconeogenesis and cysteine and methionine metabolism. The results of molecular docking showed that chrysin-7-O-glucuronide and diosmetin-7-O-rutinoside may be the crucial components that exert myocardial protective activity. Western blot showed that GLXB administration reversed the expression levels of Pck1, Cdo1, Cth, Alb, Bcl2, and Ccnd1. This study has elucidated that GLXB could alleviate MI in rats by modulating WNT and PI3K/AKT signaling pathways, thereby reducing inflammation and apoptosis as well as improving energy metabolism.

Dissection of genetic architecture for desirable traits in sugarcane by integrated transcriptomics and metabolomics

Sugarcane is an important sugar and energy crop. Breeding varieties with high yield and sugar, strong stress tolerance, as well as beneficial for mechanized harvesting are the goal of sugarcane breeder. In the present study, transcriptomics and metabolomics were conducted to explore the molecular basis for outstanding performance of five elite varieties GT42, GT44, LC05-136, YZ08-1609, and YZ05-51, along with the cross-parent CP72-1210 compared to ROC22. Transcriptomics revealed a total of 18,353 differentially expressed genes (DEGs) and several regulatory pathways, including carbon fixation, starch and sucrose metabolism, phenylpropanoids biosynthesis, flavonoid biosynthesis, cysteine and methionine metabolism, as well as zeatin biosynthesis. Expression patterns of genes involved in these pathways confirmed their role in determining the agronomic traits. Besides, metabolomics disclosed 175 differentially accumulated metabolites (DAMs), including specific metabolites of amino acids and secondary metabolites. Furthermore, conjoint analysis of transcriptomics and metabolomics highlighted the manipulation of 113 genes led to changed levels of 20 metabolites associated with carbon fixation, sucrose accumulation, phytohormone response and secondary metabolism. Finally, we depicted here a blueprint outlining the genetic basis underlying the desirable traits in sugarcane. This study will accelerate the dissection of the molecular basis for sugarcane traits and provide targets for molecular breeding.

Analysis of genetic requirements and nutrient availability for Staphylococcus aureus growth in cystic fibrosis sputum.

Staphylococcus aureus is a major cause of lung infections in people with cystic fibrosis (CF). This work identifies genes required for S. aureus growth in this niche, which represent potential targets for anti-Staphylococcal treatments. We show that genes involved in surviving metal starvation are required for growth in CF sputum. We also found that the primary regulator of cysteine metabolism, CymR, plays a critical role in preventing cysteine intoxication during growth in CF sputum. To support these models, we analyzed sputum from 11 individuals with CF to determine concentrations of calprotectin, nutrient metals, and low-molecular-weight thiols, which have not previously been quantified together in the same samples.

Global and Targeted Metabolomics for Revealing Metabolomic Alteration in Niemann-Pick Disease Type C Model Cells.

Niemann-Pick disease type C (NPC) is an inherited disorder characterized by a functional deficiency of cholesterol transport proteins. However, the molecular mechanisms and pathophysiology of the disease remain unknown. In this study, we identified several metabolite characteristics of NPC that may fluctuate in a cellular model of the disease, using both global and targeted metabolomic analyses by liquid chromatography/tandem mass spectrometry (LC-MS/MS). Three cell lines, HepG2 cells (wild-type[WT]) and two NPC model HepG2 cell lines in which NPC1 was genetically ablated (knockout [KO]1 and KO2), were used for metabolomic analysis. Data were subjected to enrichment analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The enrichment analysis of global metabolomics revealed that 8 pathways in KO1 and 16 pathways in KO2 cells were notably altered. In targeted metabolomics for 15 metabolites, 4 metabolites in KO1 and 10 metabolites in KO2 exhibited statistically significant quantitative changes in KO1 or KO2 relative to WT. Most of the altered metabolites were related to creatinine synthesis and cysteine metabolism pathways. In the future, our objective will be to elucidate the relationship between these metabolic alterations and pathophysiology.