Search Results (360)

Distention of the urinary bladder wall during filling stretches the urothelium and induces the release of chemical mediators, including adenosine 5′-triphosphate (ATP) and prostaglandins (PGs), that transmit signals between cells within the bladder wall. The urothelium also releases soluble nucleotidases (s-NTDs) that control the availability of ATP and its metabolites at receptor sites in umbrella cells and cells deeper in the bladder wall, as well as in the urine. This study investigated whether PGs regulate the intravesical breakdown of ATP by s-NTDs. Using a murine decentralized mucosa-only bladder model and an HPLC technology with fluorescence detection, we evaluated the decrease in ATP and increase in ADP, AMP, and adenosine (ADO) in intraluminal solutions (ILS) collected at the end of physiological bladder filling. PGD₂, PGE₂, and PGI₂, but not PGF_2α, inhibited the conversion of AMP (produced from ATP) to ADO, likely due to a suppressed intravesical release of s-AMPases. The effects of exogenous PGD₂, PGE₂, and PGI₂ were mediated by DP1/DP2, EP2, and IP prostanoid receptors, respectively. Activation of either DP1 or DP2 receptors by endogenous PGD₂ also led to AMP increase and ADO decrease in ILS-containing ATP substrate. Finally, PGs produced by either COX-1 or COX-2 inhibited the hydrolysis of AMP to ADO. Together, these observations suggest that (1) endogenous PGs (chiefly PGD₂, and to lesser degree PGE₂ and PGI₂) allow release of s-NTDs like s-ATPases and s-ADPases but impede the formation of ADO from intravesical ATP by inhibiting the release of s-NTDs/s-AMPases; (2) it is possible that high concentrations of PGD₂, PGE₂ and PGI₂, as anticipated in inflammation or bladder pain syndrome, delay the ADO production and prolong the action of excitatory purine mediators; and (3) either COX-1 and COX-2 are constitutively expressed in the mouse bladder mucosa or COX-2 is induced by distention of the urothelium during bladder filling. Full article

Phosphine (PH₃) is a fumigant often used to control insect pests, but its metabolic effects on insect physiology remain unclear. In this study, a comparative metabolomics analysis was performed to elucidate the physiological metabolic pathways affected by PH₃ exposure in Planococcus citri, and significant changes in the metabolic profiles induced by PH₃ treatment were identified. Principal component analysis and correlation analysis revealed different metabolic changes, and a total of 45 metabolites were identified and mapped to metabolic pathways using the KEGG database. PH₃ exposure inhibited energy metabolism by down-regulating riboflavin and flavin adenine dinucleotide, which are important cofactors in oxidative phosphorylation and reactive oxygen species generation. In addition, purine and pyrimidine metabolism, essential for nucleotide synthesis and cellular energy homeostasis, were also suppressed. Notably, lipid metabolism was significantly altered, and the juvenile hormone biosynthesis pathway was down-regulated. These results suggest that PH₃ inhibits electron transport chain activity, induces oxidative stress, and disrupts lipid homeostasis. This study enhances our understanding of the potential biomarkers of PH₃ exposure, the metabolic processes involved, and the resistance mechanisms that pests may develop in response to such exposure. Full article

Rhododendron tomentosum Harmaja is a marsh plant known for its high content of bioactive components, including essential oil, flavonoids, and phenolic acids. In the current work, the effects of cultivation mode (agar, liquid stationary, shake flask, and temporary immersion) and experiment duration (30, 60, and 90 days) on the growth and contents of non-volatile phenolics in Rhododendron tomentosum microshoots were investigated. Agar and liquid stationary cultures provided the highest dry biomass yield per liter, but their dry weight productivities per day were the lowest among the tested systems. Agitated and temporary immersion cultures, on the other hand, were the most productive in terms of fresh and dry biomass yield per day. LC-DAD-ESI-MS analysis of extracts from microshoots and wild-grown plants revealed similarities in phenolic composition: in both cases, the presence of catechin, chlorogenic acid, and flavonoids of flavonol type (mainly glycosides of quercetin and myricetin) was confirmed. The qualitative composition of the phenolic fraction was not affected by experiment duration and cultivation mode. As determined by HPLC analysis, shake flask and temporary immersion cultures were characterized by the highest phenolic contents: up to 37.5 and 26 mg/g dry weight, respectively. The maximum productivities of the above systems were equal to 18 and 13.5 mg/L/d, respectively. Full article

Polystyrene nanoplastics (NPs) threaten agricultural ecosystems and the food chain; however, their hepatotoxicity in chickens, a key poultry species, remains unclear. This study investigated the effects of chronic NP exposure on hepatic metabolism to evaluate food safety risks in poultry products. Chickens were orally exposed to 100 nm polystyrene NPs via feed for 120 days. Histopathological evaluation, serum biochemical analysis revealed hepatotoxicity in NP-exposed poultry, characterized by histopathological liver injury, elevated lipid droplet accumulation, significantly increased alanine aminotransferase (ALT) activity, and elevated triglyceride (TG) levels (p < 0.05). Untargeted LC-MS/MS Metabolomics profiling identified 193 differentially abundant metabolites—predominantly organic acids and lipids—with L-leucine and NADH emerging as pivotal metabolic hubs. A KEGG pathway analysis demonstrated significant enrichment in purine metabolism and oxidative phosphorylation, while a gene set enrichment analysis (GSEA) confirmed the suppression of ABC transporters. Notably, the key biomarkers 9-cis-retinal and phenylalanyl phenylalanine were significantly altered, reflecting metabolic disturbances linked to NPs exposure. Overall, this study characterized exposure-associated metabolic signatures and established NP-induced hepatic injury phenotypes in poultry production systems. Full article

Deoxynivalenol (DON) is a common mycotoxin that causes immunosuppression in pigs. Its effects on cellular metabolism remain unclear. In this study, we investigate DON-induced metabolic alterations in porcine alveolar macrophage cell line 3D4/21 using non-targeted metabolomics. MTT assays showed DON reduced cell viability in a concentration- and time-dependent manner. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) revealed distinct metabolic profiles between control and DON-treated groups. Metabolomic analysis identified 127 differential metabolites (VIP > 1, p < 0.05), primarily in purine metabolism, glutathione metabolism, and arginine–proline metabolism. Integration with transcriptomic data confirmed that these pathways play key roles in DON-induced immunotoxicity. Specifically, changes in purine metabolism suggested disrupted nucleotide synthesis and energy balance, while glutathione depletion indicated weakened antioxidant defense. These findings provided a systems biology perspective on DON’s metabolic reprogramming of immune cells and identified potential therapeutic targets to reduce mycotoxin-related immunosuppression in swine. Full article

Background: Salmonella infections pose a serious threat to both animal and human health worldwide. Notably, there is an increasing trend in the resistance of Salmonella to fluoroquinolones, the first-line drugs for clinical treatment. Methods: Utilizing Salmonella Typhimurium CICC 10420 as the test strain, ciprofloxacin was used for in vitro induction to develop the drug-resistant strain H1. Changes in the minimum inhibitory concentrations (MICs) of various antimicrobial agents were determined using the broth microdilution method. Transcriptomic and metabolomic analyses were conducted to investigate alterations in gene and metabolite expression. A combined drug susceptibility test was performed to evaluate the potential of exogenous metabolites to restore antibiotic susceptibility. Results: The MICs of strain H1 for ofloxacin and enrofloxacin increased by 128- and 256-fold, respectively, and the strain also exhibited resistance to ceftriaxone, ampicillin, and tetracycline. A single-point mutation of Glu469Asp in the GyrB was detected in strain H1. Integrated multi-omics analysis showed significant differences in gene and metabolite expression across multiple pathways, including two-component systems, ABC transporters, pentose phosphate pathway, purine metabolism, glyoxylate and dicarboxylate metabolism, amino sugar and nucleotide sugar metabolism, pantothenate and coenzyme A biosynthesis, pyrimidine metabolism, arginine and proline biosynthesis, and glutathione metabolism. Notably, the addition of exogenous glutamine, in combination with tetracycline, significantly reduced the resistance of strain H1 to tetracycline. Conclusion: Ciprofloxacin-induced Salmonella resistance involves both target site mutations and extensive reprogramming of the metabolic network. Exogenous metabolite supplementation presents a promising strategy for reversing resistance and enhancing antibiotic efficacy. Full article

Triticale (Triticosecale Wittmack) is a versatile forage crop valued for its high yield, balanced nutrition, and environmental adaptability. However, the dough-stage triricale has higher dry matter and starch content but lower water-soluble carbohydrate levels than earlier stages, posing fermentation challenges that may impair silage quality. This study aimed to investigate the effects of lactic acid bacteria inoculation on the fermentation quality, bacterial community, and metabolome of whole-plant triticale silage at the dough stage. Fresh triticale was ensiled for 30 days without or with an inoculant containing Lactiplantibacillus plantarum and Streptococcus bovis. Fermentation quality, bacterial succession, and metabolic profiles were analyzed at multiple time points. Inoculation significantly improved fermentation quality, characterized by a rapid pH drop, increased lactic acid production, and better preservation of fiber components. Microbial analysis revealed that inoculation successfully established Lactobacillus as the dominant genus while suppressing spoilage bacteria like Enterobacter and Clostridium. Metabolomic analysis on day 30 identified numerous differential metabolites, indicating that inoculation primarily altered pathways related to amino acid and purine metabolism. In conclusion, inoculating dough-stage triticale with this LAB combination effectively directs the fermentation trajectory. It enhances silage quality not only by optimizing organic acid profiles and microbial succession but also by modulating key metabolic pathways, ultimately leading to improved nutrient preservation. Full article

In recent years, gut microbiota has emerged as a critical regulator of gastrointestinal health and disease, with its role in inflammatory bowel disease (IBD)—including Crohn’s disease and ulcerative colitis—being particularly significant. Among the many factors influencing the gut microbiota, dietary components such as fibers, fats, and polyphenols have received substantial attention. However, nitrogen-containing compounds, such as amino acids, nitrates, urea, and even nucleic acids, such as purines, remain underexplored despite their integral role in shaping microbial ecology, host metabolism, and immune responses. Some of these compounds are metabolized by gut bacteria into bioactive molecules such as short-chain fatty acids, ammonia, and nitric oxide, which exert diverse effects on mucosal integrity and inflammation. IBD pathophysiology is characterized by chronic inflammation, microbial dysbiosis, and compromised epithelial barriers. Nitrogen metabolism contributes significantly to these processes by influencing microbial composition, metabolite production, and host immune pathways. The breakdown of various nitrogen-containing compounds in the body leads to the production of byproducts, such as ammonia and hydrogen sulfide, which have been implicated in mucosal damage and immune dysregulation. At the same time, nitrogen-derived molecules, such as short-chain fatty acids and nitric oxide, exhibit protective effects, underscoring the dual role of dietary nitrogen in health and disease. This narrative review highlights the complex interactions between dietary nitrogen sources, gut microbiota, and IBD pathogenesis. We summarize the mechanisms by which nitrogen compounds influence microbial dynamics, identify their contributions to inflammation and barrier dysfunction, and explore their therapeutic potential. Multidisciplinary approaches integrating clinical, metabolomic, and microbiome research are essential to unravel the full scope of nitrogen’s role in gut health and identify novel therapeutic targets. Full article

Streptococcus agalactiae (SA) is a severe prevalent pathogen, resulting in high morbidity and mortality in the global tilapia industry. With increasing bacterial resistance to antibiotics, alternative strategies are urgently needed. This study aims to investigate the antibacterial activity and the underlying mechanisms of the natural product xanthohumol (XN) against SA infection in tilapia (Oreochromis niloticus). The results showed that XN could significantly reduce the bacterial loads of SA in different tissues (liver, spleen and brain) after treatment with different tested concentrations of XN (12.5, 25.0 and 50.0 mg/kg). Moreover, XN could improve the survival rate of SA-infected tilapia. 16S rRNA gene sequencing demonstrated that the alpha-diversity index (Chao1 and Shannon_e) was significantly increased in the XN-treated group (MX group) compared to the SA-infected group (CG group) (p < 0.05), and the Simpson diversity index significantly decreased. The Bray–Curtis similarity analysis of non-metric multidimensional scaling (NMDS) and principal coordinate analysis (PCA) showed that there were significant differences in microbial composition among groups. At the phylum level, the relative abundance of the phyla Actinobacteria, Proteobacteria and Bacteroidetes decreased in the MX group compared to the CG group, while the relative abundance of the phyla Fusobacteria, Firmicutes and Verrucomicrobia increased. Differences were also observed at the genus level; the relative abundance of Mycobacterium decreased in the MX group, but the abundance of Cetobacterium and Clostridium_sensu_stricto_1 increased. Metabolomics analysis revealed that XN changed the metabolic profile of the liver and significantly enriched aspartate metabolism, glycine and serine metabolism, phosphatidylcholine biosynthesis, arginine and proline metabolism, glutamate metabolism, urea cycle, purine metabolism, methionine metabolism, betaine metabolism, and carnitine synthesis. Correlation analysis indicated an association between the intestinal microbiota and metabolites. In conclusion, XN may be a potential drug for the prevention and treatment of SA infection in tilapia, and its mechanism of action may be related to the regulation of the intestinal microbiota and liver metabolism. Full article

Objectives: To explore the metabolic changes in zebrafish larvae after infection with Mycobacterium marinum, this study adopted a widely targeted metabolomic approach to analyze the changes in the overall metabolic profiles of zebrafish larvae infected for 5 days. Methods: Data were collected by liquid chromatography–tandem mass spectrometry (LC-MS/MS). Mass spectrometry data were processed using Analyst 1.6.3 and MultiQuant 3.0.3 software, and multivariate statistical analysis was carried out. The KEGG database, HMDB database, and CHEBI database were used to screen and identify differential metabolites, and metabolic pathway enrichment analysis was performed through KEGG pathways. Results: A total of 329 metabolites were detected, among which 61 differential metabolites were screened. Specifically, 41 metabolites, such as kynurenine, isoallolithocholic acid, 2′-deoxyguanosine, indole-3-carboxaldehyde, and L-lactic acid, were downregulated, while 20 metabolites, such as L-palmitoylcarnitine, myristoyl-L-carnitine, dodecanoylcarnitine, 2-isopropyl-malic acid, and 2-methylsuccinic acid, were upregulated. KEGG metabolic pathway enrichment analysis indicated that these differential metabolites were mainly involved in metabolic pathways such as pyrimidine metabolism, nucleotide metabolism, the pentose phosphate pathway, and purine metabolism. Conclusions: This study demonstrated that significant changes occurred in multiple metabolites and metabolic pathways in zebrafish larvae after infection with M. marinum. The research results have improved the understanding of zebrafish as a model organism in the field of Mycobacterium research and laid a solid foundation for subsequent metabolomic-related research using zebrafish. Full article

Hyperuricemia (HUA) is a metabolic disorder characterized by abnormal purine metabolism and/or reduced uric acid (UA) excretion. Chicory (Cichorium intybus L.), recognized in Traditional Chinese Medicine, is noted for its anti-HUA effects, particularly in enhancing intestinal UA excretion, though the underlying mechanisms remain unclear. Studies indicate that disruptions in gut microbiota and its metabolites are associated with HUA, and chicory has been demonstrated to ameliorate gut microbiota dysbiosis. Among gut microbiota-derived metabolites, butyrate, a short-chain fatty acid, plays a crucial role in gut functions and is linked to HUA. Therefore, butyrate may be pivotal in elucidating the mechanism by which chicory promotes intestinal UA excretion. This study aims to investigate whether chicory facilitates intestinal UA excretion through gut microbiota-derived butyrate and to elucidate the underlying mechanism. We employed an integrated methodology combining network biology with the NHANES database analysis to explore the pathological relationship between butyrate and HUA. Our findings were subsequently validated through animal experiments. We administered chicory to rats with HUA to ascertain whether butyrate serves as the key gut microbiota metabolite through which chicory promotes intestinal UA excretion. Furthermore, we utilized western blotting to assess the expression of core targets within the PPARγ-ABCG2 pathway associated with butyrate under conditions where animals received butyrate supplements and PPARγ agonists separately. The network biology indicates that butyrate is a crucial short-chain fatty acid influencing HUA. Analyses of NHANES data and animal experiments further confirm a significant negative correlation between butyrate and serum uric acid (SUA) levels. HUA rats exhibited intestinal barrier damage, impaired intestinal UA excretion, reduced butyrate levels, and decreased expression of PPARγ and ABCG2 proteins. Intervention with chicory in HUA rats repaired intestinal barrier damage, enhanced intestinal UA excretion, and increased both butyrate levels and the expression of PPARγ and ABCG2 proteins. Similarly, interventions with butyrate supplements or PPARγ agonists in HUA rats effectively promoted intestinal UA excretion and increased the expression of PPARγ and ABCG2 proteins. This study demonstrates that butyrate is a key metabolite produced by gut microbiota, through which chicory regulates gut microbiota to enhance intestinal UA excretion. The underlying mechanism involves the activation of the PPARγ-ABCG2 pathway, which is facilitated by elevated butyrate levels in the intestine. Full article

Background: Several recent studies have documented an increased cardiovascular risk in patients with primary hyperparathyroidism (PHPT), thereby stimulating interest in the association with uric acid (UA), a metabolite linked to cardiovascular disease and chronic kidney disease (CKD) progression, whose role in these conditions is still the subject of study. The aim of this review is to summarize the underlying pathophysiological mechanisms of the PHPT-UA relation and discuss their potential clinical implications. Methods: We conducted a comprehensive literature review, with a focus on the physiological and clinical aspects of the relationship between PHPT and UA. Results: The evidence in the literature supports the association between PHPT and elevated UA levels, although the underlying mechanisms still need to be elucidated. Key mechanisms seem to involve tubular and intestinal transporters, particularly the ABCG2 transporter, as well as indirect effects mediated by hypercalcemia and inflammatory processes. Conclusions: The association between PHPT and UA, though recognized for years, highlights the existence of linked pathophysiological mechanisms between mineral and purine metabolism. However, the current knowledge does not clarify whether uric acid plays an active role in the development of complications related to hyperparathyroidism or if it just represents an indirect marker of metabolic dysfunction. In the absence of specific guidelines, measuring UA levels to screen for hyperuricemia, especially in patients with additional risk factors, should be considered to prevent related complications. Future studies could clarify the role of UA in PHPT, improving our understanding of the disease and potentially leading to new therapeutic strategies to prevent cardiovascular, renal and joint manifestations. Full article

Rumen microbiota and metabolites play important roles in energy metabolism and immune regulation in the host. However, the underlying mechanisms of their interaction with the host to regulate yak plateau adaptation remain unknown. In this study, the effects of altitude on the rumen microbiome, metabolome, and fermentation parameters of yaks were analyzed. The fiber content of pasture grasses increased with altitude, while crude protein content was significantly higher at an altitude of 2800 m (T2800) compared to an altitude of 4500 m (T4500) (p < 0.05). The acetic acid, propionic acid, and volatile fatty acids of yaks in the T4500 group were significantly higher than in the T2800 group (p < 0.05). Simpson’s index of rumen microorganisms in the T4500 group of yaks was significantly higher than in T2800 and T3500 yaks. The relative abundance of Rikenellaceae_RC9_gut_group and Succiniclasticum was significantly higher in T4500 than in T2800, while Prevotella and Streptococcus were more abundant in T2800 than in T4500. Rumen metabolomics analyses revealed that yak rumen metabolites at different altitudes were influenced by forage and altitude, mainly affecting energy metabolism and fatty acid biosynthesis (such as purine and glycerophospholipid metabolism). In summary, altitude may influence rumen microbes and metabolites through pasture nutrient composition. Full article

Latilactobacillus sakei (L. sakei) and Staphylococcus carnosus (S. carnosus) are common starters for fermented sausages. However, the mechanism underlying the effects of these two microorganisms on co-cultivation in sausages remains unclear. This study compared the changes in metabolomics following fermentation by L. sakei and S. carnosus individually and in combination. After two days of fermentation, the pH values of the LS (Latilactobacillus Single), SC (Staphylococcus Single), and LSSC (Latilactobacillus-Staphylococcus Combined) groups were 4.59, 5.19, and 4.86. By comparing the common differential metabolites among the three groups, it was found that the content of N2-acetyl-L-ornithine decreased after single fermentation with L. sakei, while the content of N2-acetyl-L-ornithine increased after single fermentation with S. carnosus and combined fermentation with L. sakei. Additionally, KEGG pathway analysis identified eight key metabolic pathways, including purine metabolism, starch and sucrose metabolism. In addition, it was found that L. sakei produced D-Galactose during fermentation, which could be utilized by S. carnosus. The co-fermentation of L. sakei and S. carnosus promoted the production of D-sorbitol. Our results suggest that the metabolic interactions between L. sakei and S. carnosus increase the number of functional metabolites in co-fermented sausages. These findings provide valuable insights and new research directions for the study of LAB and CNS interactions, as well as for the development of fermentation agents. Full article

Low-temperature stress serves as a critical abiotic stressor that severely restricts fish survival, biogeographic distribution, and aquaculture productivity. Pelteobagrus vachelli, an economically significant freshwater fish species, displays marked sensitivity to low-temperature stress; however, its molecular adaptive mechanisms remain poorly characterized. In this study, we systematically investigated hepatic and intestinal cold stress responses in P. vachelli through a 7-day acute low-temperature exposure trial (6 °C and 11 °C), integrating histopathological examination, physiological–biochemical assays, metabolomics, and 16S rRNA sequencing. Histopathological observations revealed pronounced hepatic vacuolar degeneration, nuclear dissolution, and enhanced inflammatory cell infiltration under low-temperature conditions. Concurrently, immune-related enzymatic activities—including aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (APK)—were significantly elevated. Furthermore, substantial perturbations in antioxidant defense systems were detected, as indicated by altered superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities, alongside malondialdehyde (MDA) accumulation. Metabolomic profiling identified 539 differentially abundant metabolites, with pathway enrichment analysis highlighting marked alterations in FoxO signaling, amino acid metabolism, glycerophospholipid metabolism, ABC transporter, and Purine metabolism. Gut microbiome sequencing demonstrated cold-induced structural dysbiosis within the intestinal microbiota. Correlation analyses revealed robust linkages between hepatic injury biomarkers/metabolites and specific intestinal microbial taxa. Collectively, this study delineates the interplay between hepatic metabolic reprogramming and gut microbiota dysbiosis during cold adaptation in P. vachelli, establishing a theoretical framework for developing gut–liver axis-targeted strategies to augment cold tolerance in aquatic species. Full article