Search Results (480)

The global seafood industry faces persistent challenges related to product quality, safety, and authenticity, driven by complex supply chains, increasing demand, and the perishable nature of aquatic products. Traditional analytical methods often fall short in providing rapid, comprehensive, and non-destructive insights into the intricate biochemical changes occurring in seafood. ¹H Nuclear Magnetic Resonance (¹H NMR) spectroscopy has emerged as a powerful and versatile tool for metabolomics, offering a holistic view of the low-molecular-mass compounds (metabolites) present in biological samples. The present study applied ¹H NMR for chemical fingerprint identification in mullets (Mugil liza) from Brazil. Dorsal muscle samples were taken from the fish during summer, autumn, and winter. The procedure involved freeze-drying the muscle tissue, thereafter extracting polar metabolites using designated solvents (methanol, water, and chloroform), and analyzing them using a 600 MHz spectrometer. As a result, 23 metabolites related to degradation biomarkers, essential metabolites, energy expenditure, and muscle structure were identified. The statistical analysis demonstrated a distinct separation between the geographical origins (RJ vs. SC), mostly influenced by variations in the concentrations of lactate, histidine, threonine, phenylalanine, and ornithine. Factors like fish size and seasonal variations did not markedly affect the overall metabolic profile, underscoring the reliability of these chemicals as stable origin indicators. The Principal Component Analysis identified two distinct groups of metabolites, establishing a profile for each geographical origin. The developed protocol can be applied to the processes of geographical identification. Thus, the ¹H NMR tool was efficient in determining metabolites that can be considered biomarkers in analyses for seafood traceability. Full article

This study compared intestinal polyamine metabolism and barrier function between Ningxiang (NX) and Duroc × Landrace × Yorkshire (DLY) piglets under baseline conditions and following ETEC challenge. Experiment 1 (baseline, n = 12/breed) assessed colonic barrier integrity, immune status, polyamines, and microbiota. Experiment 2 (ETEC challenge, n = 8/group/breed) evaluated responses to oral ETEC (10⁹ CFU) over 3 days. Under baseline conditions, NX piglets showed superior barrier integrity, higher goblet cell numbers and mucin 2 (MUC2) protein expression, and lower plasma levels of intestinal permeability markers—diamine oxidase (DAO), D-lactate (DLA), and endotoxin (ET)—compared with DLY piglets. NX piglets also exhibited reduced colonic pro-inflammatory cytokine levels (IL-6 and IL-1β) and higher expression of immune-related markers (CD3, CD68, and IgA) versus DLY piglets. In contrast, DLY piglets displayed more active microbial polyamine metabolism in the colon, with higher concentrations of putrescine, spermidine, and spermine, as well as increased ornithine decarboxylase (ODC) expression. 16S rRNA sequencing revealed greater microbial diversity and enrichment of taxa (Muribaculaceae_unclassified, Prevotella) in NX piglets, whereas DLY piglets showed enrichment of polyamine-associated genera (Collinsella, Veillonella). Following the ETEC challenge, DLY piglets displayed pronounced polyamine upregulation, including elevated polyamine levels and ODC1 expression. Conversely, NX piglets maintained more stable polyamine metabolism, higher expression of tight junction proteins (ZO-1 and occludin), lower plasma permeability markers, reduced pro-inflammatory cytokine expression (IL-6, IL-1β, IL-22), and increased anti-inflammatory IL-10 expression. Collectively, these findings demonstrate that NX piglets possess superior intestinal barrier integrity and immune maturity, while DLY piglets exhibit a more active but stress-responsive polyamine metabolic phenotype. The divergent metabolic and immune responses to ETEC challenge underscore the distinct strategies employed by these two breeds in maintaining gut homeostasis. These findings provide preliminary insights that may inform future breeding strategies aimed at enhancing intestinal health and disease resistance in pigs, pending validation in broader genetic backgrounds and mechanistic studies. Full article

Objectives: Allogeneic stem cell transplantation (HSCT) is curative in acute myeloid leukemia (AML) but is limited by relapse and non-relapse mortality (NRM). Metabolomic prognostic value is unclear. We assessed whether plasma metabolite profiles at diagnosis, pre-transplant, and post-transplant are associated with overall survival (OS) and cause-specific mortality. Methods: We retrospectively analyzed plasma metabolites from 63 AML patients undergoing HSCT (263 samples). Results: Higher levels of valine (hazard ratio [HR] 24.454), citrulline (HR 20.478), 5-oxoproline (HR 11.766), and glutamine (HR 8.701) associated with higher NRM, while inosine diphosphate (HR 0.091) and pyridoxamine-5′-phosphate (HR 0.313) associated with lower NRM. For relapse-related mortality (RRM), higher levels of phenylalanine (HR 26.585), leucine/isoleucine (HR 10.755), indolepyruvate (HR 7.676), and creatinine (HR 13.874) were associated with higher RRM, while trans-4-hydroxy-L-proline (HR 0.101) was associated with lower RRM. Higher post-transplant ornithine (HR 0.063), 3-sulfocatechol (HR 0.590), and indole-3-acetate (HR 0.359) were associated with improved OS. Mixed-effects modelling identified lower dehydroascorbate and citrate in relapsed patients, with dehydroascorbate remaining significant after false discovery rate adjustment. Conclusions: Metabolomic profiling nominated candidate metabolites for validation in larger prospective studies and elucidated mechanistic pathways, potentially informing novel interventions or risk-adapted monitoring strategies in HSCT. Full article

Selenium (Se) influences plant growth, yet its molecular regulation of amino acid metabolism in oat seedlings remains unclear. Through transcriptomic and metabolomic analyses, this study identified three major affected pathways: tryptophan metabolism (16 differentially expressed genes [DEGs], 13 differentially expressed metabolites [DEMs]), glycine, serine, and threonine metabolism (19 DEGs, 10 DEMs), and arginine and proline metabolism (24 DEGs, 13 DEMs). The T0.02 treatment (0.02 g/kg Na₂SeO₃) precisely regulates metabolism by selectively upregulating dimethylglycine in the glycine, serine, and threonine pathway and activating key genes (PRODH2, amiE2, AMD2) in the arginine–proline pathway, thereby promoting the growth of oat seedlings. The T0.1 treatment (0.1 g/kg Na₂SeO₃), promoted the accumulation of glycerate and threonine by upregulating the expression of two key genes (HPR3, ItaE1) related to glycine, serine, and threonine metabolism. Simultaneously, it enhanced the accumulation of L-ornithine, putrescine, 4-guanidinobutyric acid, and γ-aminobutyric acid through the upregulation of four key genes (ARG, ODC1, amiE1, and ALDH3) associated with arginine and proline metabolism. Additionally, the upregulation of key genes (ALDH2, 5-HTP) involved in tryptophan metabolism facilitated the accumulation of 5-methoxyindoleacetic acid and serotonin. This study primarily reveals the accumulation patterns of amino acid metabolites in oat seedlings subjected to selenium treatment and identifies key genes and metabolic pathways involved in the molecular response process. Furthermore, the research preliminarily elucidates potential regulatory nodes through which selenium treatment enhances amino acid accumulation, providing significant insights for understanding the comprehensive effects of selenium treatment on the stress resistance mechanisms of oat seedlings. Full article

Background/Objectives: Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are effective treatments for obesity, but substantial weight regain is common after therapy is discontinued. This study investigated whether probiotic strains with anti-obesity effects could enhance GLP-1RA-induced weight loss and attenuate post-treatment weight rebound. Methods: Candidate lactic acid bacteria were screened for anti-obesity efficacy in a high-fat-diet (HFD)-induced obese mouse model, and the selected strain was further characterized using metabolomic profiling of culture supernatants. To examine its interaction with GLP-1RA therapy, obese mice received dulaglutide for 4 weeks and were monitored for 2 weeks after treatment withdrawal, while the probiotic was orally administered for a total of 6 weeks. Body weight, glycemic parameters, and muscle strength were assessed throughout the study. Results: Limosilactobacillus fermentum GB102 reduced body weight and improved glycemic control in HFD-fed mice. These metabolic benefits were associated with alterations in circulating metabolic hormones, including adipokines, along with attenuated inflammatory responses in adipose tissue. Metabolomic profiling revealed that GB102 produced high levels of succinic acid, a metabolite previously linked to thermogenic activation. This strain increased whole-body energy expenditure in HFD-fed mice, produced glutamine, and showed enhanced conversion of arginine into ornithine and citrulline. When combined with dulaglutide, GB102 enhanced weight loss, preserved muscle strength, and attenuated both weight regain and glycemic rebound following dulaglutide withdrawal. Conclusions: These findings suggest that energy-metabolism-enhancing probiotics such as GB102 may enhance the metabolic effects of GLP-1RA therapy and help attenuate weight regain after treatment discontinuation. Full article

Ornithine decarboxylase (ODC) functions as the rate-limiting enzyme in the polyamine (PA) biosynthetic pathway. It catalyzes the decarboxylation of L-ornithine to produce putrescine, thereby initiating the biosynthesis of polyamines. Polyamines are a class of widely distributed polycationic aliphatic compounds in living organisms, including putrescine, spermidine, and spermine. They serve not only as critical regulators of cell growth, proliferation, and differentiation, but also as important signaling molecules involved in plant responses to environmental stress and key precursors in the biosynthesis of diverse secondary metabolites. Focusing on recent advances in plant ODC research, this review summarizes the characteristics and evolutionary relationships of the ODC gene family, the biochemical properties and catalytic mechanism of the enzyme, and its multiple physiological roles in growth, development, secondary metabolism, and stress adaptation. Furthermore, we discuss the complex regulatory mechanisms governing ODC activity at both transcriptional and post-translational levels, with a critical gap in understanding the post-translational regulation of ODC in plants, particularly the mechanisms governing its degradation. Unlike in animals, where antizymes mediate ODC degradation, functional analogs of antizymes have not yet been identified in plants, leaving the degradation pathway largely unexplored. Finally, we review the applications of plant genetic modification targeting ODC in enhancing the production of valuable secondary metabolites in medicinal plants and improving stress tolerance in crops, along with perspectives on future research directions. This review illustrates the diversity of ODC functions and the complexity of its regulatory mechanisms in plant growth, development, stress responses, and secondary metabolism. It also provides a theoretical foundation and insights for exploring ODC as a target for plant genetic modification, which is promising for improving the economic traits and stress resistance of horticultural plants. Full article

Sepsis is a life-threatening syndrome characterized by dysregulated host responses to infection. In addition to early hyperinflammation, many patients develop profound immune suppression, and multiple targeted immunotherapies have failed to improve outcomes, highlighting the need for actionable biomarkers and new therapeutic strategies. Here, we integrated metabolomic and transcriptomic profiling of peripheral blood mononuclear cells (PBMCs) and splenocytes in rat models of polymicrobial sepsis to identify metabolites associated with immune dysfunction. Candidate findings were validated using in vivo supplementation studies and in vitro functional assays, and clinical relevance was assessed in PBMCs from patients with sepsis and healthy volunteers. Across omics datasets, intracellular aspartate (ASP) was consistently reduced in immune cells during sepsis and was associated with features of immune paralysis. Supplementation with L-ornithine L-aspartate (LOLA), an ASP source, improved survival in septic rats, enhanced bacterial clearance, and mitigated acute kidney injury. In vitro, pharmacologic or genetic disruption of ASP production impaired phagocytosis and cytokine responses, which were partially rescued by ASP supplementation. Consistently, patients with sepsis exhibited lower intracellular ASP levels in PBMCs than healthy volunteers. Together, these results support a critical role for ASP in maintaining immune competence during sepsis and suggest that intracellular ASP may serve as a biomarker of immune suppression and a potential therapeutic target. Full article

Small for gestational age (SGA) is often used as a proxy for fetal growth restriction (FGR), yet not all FGR fetuses are born SGA. SGA individuals, particularly those with catch-up growth, have increased cardiometabolic risk. We therefore studied infants and children from pregnancies at increased FGR risk, irrespective of birthweight. Two cohorts enriched for suboptimal fetal growth were recruited: an infant cohort (N = 80) to examine relationships between fetal weight trajectory and postnatal growth and a cohort of children aged 3–7 years (N = 80), 31 of whom provided blood samples for transcriptome and metabolome analyses. In infants, fetal weight trajectory correlated negatively with BMI change from birth to three months (R = −0.40, p = 0.004) and six months (R = −0.38, p = 0.012), as well as with skinfold, abdominal and arm circumferences. In children, supervised transcriptome analysis highlighted a pathway including ARG1. Unsupervised analysis had previously identified two SBP-differentiated groups; novel findings include LATS1, implicated in SBP GWAS, as the most significant gene, and GHRL, suggesting appetite-regulation mechanisms underlie SBP differences. Ornithine, a differentially expressed metabolite between fetal and childhood weight trajectory quartiles, together with ARG1, suggested involvement of the arginine-nitric oxide pathway. Early life indicators of cardiometabolic risk have been elucidated, highlighting pathways to inform future prevention. Full article

N-Acetyl-L-glutamate kinase (NAGK) catalyzes the first committed step in arginine biosynthesis in organisms that perform the cyclic pathway of ornithine synthesis. In cyanobacteria and most Archaeplastida, the activity of NAGK is controlled by the PII signal transduction protein. During evolution, representatives of the class Mamiellophyceae, Ostreococcus and Bathycoccus lost the gene encoding PII, while Micromonas retained this gene. Here, we perform coupled enzyme and pull-down assays and show that M. commoda NAGK is activated by N-acetyl-L-glutamate and inhibited by arginine but is not controlled by PII proteins. This loss may have been compensated for by the enzyme’s low sensitivity to arginine. In contrast, M. commoda PII relieved Chlamydomonas reinhardtii NAGK from feedback inhibition by arginine. These observations suggest that M. commoda NAGK possesses a unique feature: it has lost the ability to interact with PII protein. The findings are discussed in the context of the relationship between NAGK control and the PII role in Mamiellophyceae. Full article

A 78-year-old woman with a history of rheumatoid arthritis (treated with methotrexate) developed disturbed consciousness, emesis, and intestinal perforation. Initial labs revealed hyperammonemia (189 μg/dL) and hypertonic dehydration. Despite ammonia normalization, her neurological status improved only slightly, necessitating additional tests. Cerebrospinal fluid analysis showed no pleocytosis but positive oligoclonal bands and markedly elevated myelin basic protein (>500 pg/mL). Serum autoimmune markers were negative, including anti-aquaporin-4 (AQP4), anti-myelin oligodendrocyte glycoprotein (MOG), and anti-glial fibrillary acidic protein (GFAP) antibodies. MRI revealed T2/DWI-hyperintense lesions in the left parietal lobe and cerebellum. Crucially, extensive T2/DWI-hyperintense lesions with diffusion restriction spanned the white matter from the medulla oblongata to the lumbar spinal cord. Axial spinal DWI demonstrated diffuse hyperintensity throughout the entire white matter, accompanied by gray matter atrophy. Subsequent metabolic screening revealed low folate and hypocupremia (34 μg/dL) as well as urinary orotic acid and low serum citrulline, suggesting late-onset ornithine transcarbamylase (OTC) deficiency. Given the clinical context, this was interpreted as a metabolic breakdown rather than an established genetic diagnosis. This case is characterized by a long, diffusion-restricted lesion from the brainstem to the spinal cord that does not correspond to vascular territories. She experienced sudden death. We hypothesize that an underlying metabolic disorder, nutritional deficiencies and drug-induced neurotoxicity contributed to lesion formation. Full article

Nitrite is a common toxic substance in aquaculture, and microplastics are environmental pollutants capable of adsorbing small molecules/particles. Shrimp rely mainly on the hepatopancreas to accomplish detoxification metabolism. In this study, we investigated the individual and combined effects of nitrite and microplastics on the physiological function of the P. vannamei hepatopancreas. The results demonstrated that both nitrite and microplastics induced morphological damage, with the combined stress exacerbating tissue damage. Oxidative stress biochemical indicators were disrupted, and most enzyme activities and gene expression levels were upregulated to varying degrees in each experimental group. The expression levels of immune genes (cytC, CASP-3, Crus, ALF, and proPO), detoxification metabolism genes (CYP450, EH1, SULT, and UGT), and oxidative-stress-related genes (ROMO1, SOD, GPx, and Trx) exhibited different fluctuations. Nitrite and microplastic stress resulted in altered hepatopancreatic function, mainly involving amino acid biosynthesis and metabolism, ABC transporters, oxidative phosphorylation, and the mTOR pathway. We identified 17 metabolic biomarkers, including 6 lipids (Oleic acid, Prostaglandin G2, Linoleic acid, Palmitic acid, Docosahexaenoic acid, Docosapentaenoic acid), 6 amino acids (L-Leucine, Agmatine, L-Arginine, L-Tyrosine, Ornithine, N-Acetylornithine), and 5 carbohydrates (Glyceric acid, Citric acid, D-Mannose, Sorbitol, Fumaric acid). These findings suggest that nitrite and microplastic stresses cause hepatopancreatic tissue damage and induce oxidative stress, physiological and metabolic dysfunction in the shrimp P. vannamei, thereby impacting its normal physiological functions. Full article

In Australian Cattle Dogs (AUCDs), cystinuria was reported to be an autosomal dominant trait caused by a 6 bp deletion in the SLC3A1 gene (type II-A). Here we report an androgen association in this breed. A family of 11 adult AUCDs (five intact and one neutered male and five females) was genotyped for the SLC3A1 c.1095_1100del variant, and urine was examined for concentrations of cystine, ornithine, lysine, and arginine (COLA). Among this family, three males and five females tested heterozygous for the mutation, while all other AUCDs were homozygous for the wild-type allele. The two heterozygous intact males had severe COLA-uria, which decreased markedly after castration. Neither the third heterozygous male with a history of cystine calculi but already castrated nor the five heterozygous females exhibited increased COLA-uria. Heterozygosity for the 6 bp deletion in the SLC3A1 gene was associated with cystinuria in intact male AUCDs, but not in females. Castration of the heterozygous males reduced the cystinuria. Either the type II-A cystinuria in the AUCDs is an androgen-associated dominant trait, or this family also has another type III (androgen-dependent) cystinuria. Larger surveys are needed to further define the type(s) of cystinuria and effects of castration in AUCDs. Full article

We present a computational study that precedes the potential interactions between SARS-CoV-2 helicase (NSP13) and selected host proteins implicated in chaperone-assisted folding and polyamine metabolism. Using structure-based modelling and protein–protein docking (BioLuminate v4.6), followed by all-atom molecular dynamics (MD) simulations (GROMACS v2018.6), and comparative MM-GBSA scoring (HawkDock v2), we evaluated the stability and interface properties of NSP13 complexes with cytosolic heat shock proteins; heat shock protein 40 (HSP40), heat shock protein 70 (HSP70), heat shock protein 90 (HSP90) and the polyamine biosynthesis enzyme ornithine decarboxylase (ODC). Docking, MD, and interface analyses indicate distinct complex behaviours: HSP70-NSP13 complexes sampled compact conformations, HSP90-NSP13 ensembles displayed greater conformational heterogeneity but more favourable comparative MM-GBSA estimates, and ODC-NSP13 interfaces were comparatively well packed. Per-residue contact mapping identified a small set of recurrent NSP13 residues, Lys22 and Asn51, as putative interaction hotspots. The reported findings herein generate testable hypotheses about NSP13 recruitment of host chaperones and modulation of polyamine metabolism that may inform downstream experimental studies. Full article

This study investigated the mechanism by which combined vacuum packaging and 0.5% (w/v) ascorbic acid treatment (VP-AsA) preserves fresh-cut potatoes at 4 °C, integrating physiological and transcriptomic analyses. Transcriptome sequencing revealed 2246 differentially expressed genes (DEGs) in the VP-AsA group. Notably, key genes involved in glutathione metabolism and NADPH regeneration—encoding glutathione reductase (GR), glutathione S-transferase (GST), isocitrate dehydrogenase (IDH), glucose-6-phosphate dehydrogenase (G6PDH), and ornithine decarboxylase (ODC)—were significantly up-regulated. This transcriptional reprogramming, which was associated with increased glutathione (GSH) content, provides a molecular basis for the enhanced antioxidant capacity observed in the treated samples, including elevated superoxide dismutase (SOD) activity, DPPH/ABTS radical scavenging capacity, and ferric reducing antioxidant power (FRAP). Concurrently, VP-AsA treatment reduced water migration, inhibited polyphenol oxidase (PPO) and peroxidase (POD) activities, and maintained key textural properties (hardness, fracturability, springiness, chewiness) during the first 9 days of storage. These results suggest that VP-AsA treatment preserves quality at least in part by transcriptionally activating glutathione-mediated antioxidant pathways, providing insights for fresh-cut fruits and vegetables quality control. Full article

Amino acid (AA) metabolism and the adaptation of muscles to increased physical performance are interdependent. This field study examined changes in plasma amino acid (PAA) concentrations and two metabolites (ammonia and urea) before and after cross-country (CC) competitions throughout an entire eventing season and their associations with performance outcomes in eventing horses. Twenty horses from nine different Warmblood breeds were evaluated between two and seven times across 14 international eventing competitions over a 23-week period. A total of 55 rides were sampled. Blood samples were collected at four time points: before the start (TP0), 10 min after completion of the CC ride (TP1), 30 min post-CC (TP2), and the next morning (TP3). A mixed ANOVA revealed significant effects (p < 0.05) of calendar week on PAA concentrations for asparagine, ornithine, and proline. Correlations between CC scores and PAA concentrations were observed for 4 of the 25 measured parameters. TP0 leucine concentrations and TP2 histidine concentrations correlated negatively with CC penalty score, whereas TP1 proline concentrations and TP3 alanine concentrations correlated positively with CC penalty score. These results indicate that higher plasma leucine concentrations may contribute to improved performance in eventing horses. Additionally, alanine and proline show potential as performance-related diagnostic biomarkers. Full article