Search Results (75)

To enhance the signal intensity of kynurenines, which are present at trace concentrations in biological fluids, a novel analytical approach was developed, combining pressure-assisted electrokinetic injection (PAEKI) with a mixed micelle system based on sodium dodecyl sulfate (SDS) and Brij-35. The method was applied to key compounds of the kynurenine pathway, including L-tryptophan, kynurenine, 3-hydroxykynurenine, and kynurenic acid, as well as to the aromatic amino acids (AAs) L-tyrosine and L-phenylalanine. PAEKI was performed by electrokinetic injection for 2 min at −6.5 kV (reversed polarity) and 0.5 psi (3.45 kPa) using a fused silica capillary (50 cm in length, 50 µm inner diameter). The background electrolyte (BGE) consisted of 20 mM Na₂B₄O₇ (pH 9.2), 2 mM Brij-35, 20 mM SDS, and 20% (v/v) methanol (MeOH). The limit of detection (LOD) using a diode array detector (DAD) was 1.2 ng/mL for kynurenine and ranged from 1.5 to 3.0 ng/mL for the other analytes. The application of PAEKI in conjunction with micellar electrokinetic capillary chromatography (MEKC) and solid-phase extraction (SPE) of artificial urine samples resulted in a 146-fold increase in signal intensity for kynurenines compared to that observed using the hydrodynamic injection (HDI) mode. The developed method demonstrates strong potential for determining kynurenine pathway metabolites in complex biological matrices. Full article

Background/Objectives: Lactobacillus strains are widely used as probiotics in the functional food industry and show potential for treating inflammatory bowel disease (IBD). However, the strain specificity and limited stress resistance of Lactobacillus restricts its therapeutic effectiveness. The aim of this study was to investigate the effects of dietary supplementation with microencapsulated Lactobacillus plantarum 17-1 on the intestinal immune responses, gut microbiota composition, and metabolic characteristics in colitis mice. Methods: Mice were pre-fed a diet containing microencapsulated Lactobacillus plantarum 17-1 for 3 weeks and then treated with 2.5% dextran sulfate sodium (DSS) in drinking water for 8 days to induce colitis. Results: The results showed that microencapsulated Lactobacillus plantarum 17-1 effectively alleviated clinical symptoms and histopathological features of colitis mice and suppressed the up-regulation of pro-inflammatory cytokines IL-6 and IL-17 in the colon of colitis mice. Additionally, Lactobacillus plantarum 17-1 significantly increased the relative abundance of several beneficial bacterial taxa, including Ruminococcaceae_UCG_014, Bacteroides, Prevotellaceae_UCG_001, Lactococcus, Weissella, Pediococcus, and so on. Moreover, it regulated the levels of multiple inflammation-related metabolites involved in linolenic acid metabolism, arachidonic acid metabolism, primary bile acid biosynthesis, and tyrosine metabolism. Conclusions: These results suggest that dietary supplementation with microencapsulated Lactobacillus plantarum 17-1 reduced colitis inflammation in mice by modulating the intestinal microbiota composition and metabolic characteristics, which may serve as a potential therapeutic strategy for IBD. Full article

Throughout their life cycle, plants persistent through environmental adversities that activate sophisticated stress-signaling networks, with protein kinases serving as pivotal regulators of these responses. The sucrose non-fermenting-1-related protein kinase 2 (SnRK2), a plant-specific serine/threonine kinase, orchestrates stress adaptation by phosphorylating downstream targets to modulate gene expression and physiological adjustments. While SnRK2 substrates have been extensively identified, the existing literature lacks a systematic classification of these components and their functional implications. This review synthesizes recent advances in characterizing SnRK2-phosphorylated substrates in Arabidopsis thaliana, providing a mechanistic framework for their roles in stress signaling and developmental regulation. Furthermore, we explore the understudied paradigm of SnRK2 undergoing multilayered post-translational modifications (PTMs), including phosphorylation, ubiquitination, SUMOylation, S-nitrosylation, sulfation (S-sulfination and tyrosine sulfation), and N-glycosylation. These PTMs collectively fine-tune SnRK2 stability, activity, and subcellular dynamics, revealing an intricate feedback system that balances kinase activation and attenuation. By integrating substrate networks with regulatory modifications, this work highlights SnRK2’s dual role as both a phosphorylation executor and a PTM-regulated scaffold, offering new perspectives for engineering stress-resilient crops through targeted manipulation of SnRK2 signaling modules. Full article

Phytosulfokine (PSK) is a tyrosine-sulfated pentapeptide found throughout the plant kingdom, playing key roles in plant growth, development, and responses to biotic and abiotic stresses. However, there is still a lack of a comprehensive analysis of the CsPSK gene family in Camellia sinensis. In this study, we conducted a genome-wide identification and characterized 14 CsPSK genes in tea plants, which are unevenly distributed across seven chromosomes. CsPSK genes encode proteins ranging from 75 to 124 amino acids in length, all belonging to the PSK-α type and containing conserved PSK domains. A synteny analysis revealed that the expansion of the CsPSK gene family is primarily attributed to whole-genome duplication, with homology to Arabidopsis thaliana PSK genes. A promoter region analysis identified cis-regulatory elements related to hormone and stress responses. An expression profile analysis showed that CsPSK genes are highly expressed in roots, stems, flowers, and leaves, and are induced by both biotic and abiotic stresses. Furthermore, an RT-qPCR assay demonstrated that the expression levels of CsPSK8, CsPSK9, and CsPSK10 are significantly upregulated following Discula theae-sinensis infection. These findings establish a basis for further research into the role of the CsPSK gene family in tea plant disease resistance and underlying molecular mechanisms, offering valuable perspectives for developing novel antimicrobial peptides. Full article

Background/Objectives: Prenatal depression (PND) poses a significant threat to the health of both the mother and the developing fetus. Despite its increasing prevalence, the pathophysiology of PND is not yet fully elucidated. Methods: In this study, we aimed to investigate the fecal metabolites and gut microbiota in PND patients compared to healthy controls and to explore potential correlations between these factors. Results: Through untargeted metabolomics analysis, we identified 75 significantly altered metabolites in PND patients, of which 27 were structurally annotated and implicated key pathways, such as linoleic acid metabolism and phenylalanine, tyrosine, and tryptophan biosynthesis. Notably, two Clostridia-associated enterobacteria, unclassified_c_Clostridia and unclassified_f_Lachnospiraceae, which were enriched in the PND group, were significantly positively correlated with tyrosine and negatively correlated with multiple sulfated neurosteroids. Conclusions: Our findings underscore a robust association between gut microbiota dysbiosis and metabolic disturbances in PND, with specific alterations noted in tyrosine metabolism, sulfated neurosteroid homeostasis, and linoleic acid pathways. These dysregulated metabolites—tyrosine, sulfated neurosteroids, and linoleic acid—may serve as potential diagnostic biomarkers and therapeutic targets. Moreover, their interplay provides new insights into the pathophysiological mechanisms of PND, particularly highlighting the role of gut-brain axis signaling in neuroendocrine dysregulation and inflammatory responses. However, further large-scale studies and animal models are required to validate these findings and explore detailed mechanistic pathways. Full article

Background: This study aims to explore metabolic biomarkers and pathways in breast cancer prognosis. Methods: We performed a global post-radiotherapy (RT) urinary metabolomic analysis of 120 breast cancer patients: 60 progression-free (PF) patients as the reference and 60 with progressive disease (PD: recurrence, second primary, metastasis, or death). UPLC-MS/MS (Metabolon Inc.) identified 1742 biochemicals (1258 known and 484 unknown structures). Following normalization to osmolality, log transformation, and imputation of missing values, a Welch’s two-sample t-test was used to identify biochemicals and metabolic pathways that differed between PF and PD groups. Data analysis and visualization were performed with MetaboAnalyst. Results: Metabolic biomarkers and pathways that significantly differed between the PD and PF groups were the following: amino acid metabolism, including phenylalanine, tyrosine, and tryptophan biosynthesis (impact value (IV) = 1.00; p = 0.0007); histidine metabolism (IV = 0.60; p < 0.0001); and arginine and proline metabolism (IV = 0.70; p = 0.0035). Metabolites of carbohydrate metabolism, including glucose (p = 0.0197), sedoheptulose (p = 0.0115), and carboxymethyl lysine (p = 0.0098), were elevated in patients with PD. Gamma-glutamyl amino acids, myo-inositol, and oxidative stress biomarkers, including 7-Hydroxyindole Sulfate and sulfate, were elevated in patients who died (p ≤ 0.05). Conclusions: Amino acid metabolism emerged as a key pathway in breast cancer progression, while carbohydrate and oxidative stress metabolites also showed potential utility as biomarkers for breast cancer progression. These findings demonstrate applications of metabolomics in identifying metabolic biomarkers and pathways as potential targets for predicting breast cancer progression. Full article

The protective effects of the milk fat globule membrane (MFGM) in alleviating inflammation have been reported. However, limited attention has been paid to the key fraction of milk fat globule membrane protein (MFGMP). This study investigated the protective effects of camel MFGMP against dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in mice. The results revealed that administering 50 mg/kg MFGMP significantly alleviated colonic inflammation, as evidenced by a marked decrease in IL-6, IL-1β, and TNF-α levels, along with pathological damage in DSS-induced mice with UC. MFGMP supplementation partially regulated gut microbiota dysbiosis in mice with UC by increasing α-diversity and the relative abundance of beneficial gut bacteria, such as Lactobacillus, while decreasing the abundance of Akkermansia. Additionally, MFGMP treatment exhibited significant regulatory effects on metabolites, particularly amino acid metabolism, in the feces. Specifically, this treatment restored L-valine to normal physiological levels and increased the concentrations of L-leucine, L-lysine, and L-tyrosine to nearly twice their baseline levels, whereas the concentration of L-tryptophan increased threefold. These upregulated amino acids were negatively correlated with pro-inflammatory cytokines and positively correlated with the anti-inflammatory cytokine IL-10, as indicated by Spearman’s correlation analysis. Furthermore, the significant reduction in the mRNA expression levels of WNT-1, β-catenin, and Cyclin D1 suggests that MFGMP exerts a positive effect on UC via the Wnt/β-catenin pathway. These findings indicate that MFGMP exerts a protective effect against UC by modulating intestinal microbiota and amino acid metabolism in mice, with potential implications for treating intestinal inflammatory diseases. Full article

Casparian strip integrity factors (CIFs), which are tyrosine-sulfated small peptides, are crucial genes involved in the formation and regulation of the Casparian strip and play an important role in the regulation of plant stress response. In order to explore the evolution, characteristics, role, and function of CIFs in response to continuous cropping obstacles (CCOs), the bioinformatics and gene expression analysis of CIF genes in Pogostemon cablin was carried out by determining the phylogenetic relationship, chromosome location, gene structure, and RT–qPCR results. Results showed that a total of 12 PatCIF family genes were identified on 12 different chromosomes. Promoter prediction analysis revealed 16 different cis-regulatory elements. A systematic evolutionary study of 33 species indicates CIF family genes originated from Spermatophyta. Collinearity analysis revealed P. cablin shared 19 syntenic genes with Solanum lycopersicum and only 8 with Oryza sativa. Transcriptome analysis indicated that the expression of PatCIF1–4 and PatGSO1b/1c/1f genes decreased under p-hydroxybenzoic acid treatment, and further RT–qPCR validation of four PatCIF genes was consistent with the results. AlphaFold prediction showed a protein interaction region between PatCIF1–4 mature peptide and PatGSO1b/1c/1f via the LRR domain, which provides a key binding surface for mature PatCIFs. This study offers a theoretical basis to investigate the roles of PatCIFs and PatGSO1s in CCOs and their protein interactions in P. cablin. Full article

Para-cresol (p-cresol), and its primary human metabolite p-cresol sulfate (pCS), are among the most studied gut-derived metabolites relevant to autism spectrum disorder (ASD). P-cresol is produced by bacterial modification of phenylalanine or tyrosine and is one of many potentially deleterious metabolites produced by the gut microbiota. Seventeen studies have observed p-cresol and/or p-cresol sulfate as being higher in the urine of children with autism spectrum disorder (ASD) vs. controls. P-cresol has harmful effects on the body, including within the gut, brain, kidneys, liver, immune system, and mitochondria. Some of these effects may contribute to autism and comorbid symptoms. In the gut, p-cresol acts as an antibiotic, altering the gut microbiome to favor the bacteria that produce it. In the mitochondria, p-cresol disrupts ATP production and increases oxidative stress, which is also common in autism. In the brain, p-cresol impairs neuronal development. P-cresol inactivates dopamine beta-hydroxylase, which converts dopamine to noradrenaline. P-cresol sulfate impairs kidney function and is linked to chronic kidney disease (CKD), which is more common in ASD adults. P-cresol also interferes with immune function. Three animal studies have demonstrated that p-cresol causes autism-related symptoms in mice, and that mice can be recovered by the administration of fecal microbiota transplant from healthy mice. Similarly, it was found that microbiota transplant therapy treatment in children with ASD significantly reduced p-cresol sulfate levels to normal and led to significant improvements in gastrointestinal (GI) and ASD symptoms. In summary, p-cresol and pCS likely contribute to ASD core symptoms in a substantial subset of children with ASD. Full article

The plant peptide-containing sulfated tyrosine (PSY) family plays critical roles in plant cell proliferation and stress responses. However, the functional characterization of the PSY peptide family in wheat remains unclear. This study systematically identified a total of 29 TaPSY genes at the genome-wide level, classifying them into six subgroups based on PSY-like motifs. These peptides contain a highly conserved active peptide domain, closely resembling the Arabidopsis AtPSY1 motif. All TaPSY homologs are predicted to have a sulfated tyrosine catalyzed by plant tyrosylprotein sulfotransferase (TPST). The TaPSY genes displayed distinct expression patterns across various tissues, with most genes showing higher expression levels in roots and stems. Synthetic sulfated TaPSY peptides enhanced root growth in both wild-type Arabidopsis and the tpst-1 mutant plants. In wheat, exogenous application of TaPSY peptides also promoted root growth, with the synthetic TaPSY5 peptide affecting reactive oxygen species levels in wheat taproots to stimulate primary root growth. Furthermore, transgenic Arabidopsis plants overexpressing TaPSY10 exhibited longer primary roots and increased lateral root numbers. These findings provide insights into the physiological roles of TaPSY peptides in regulating wheat root growth. Full article

Thrombin, a key enzyme in the regulation of hemostasis, has been implicated in cancer progression. This study explored the effect of recombinant tyrosine-sulfated haemathrin on cancer cell behavior and signaling pathways compared to wild-type (WT) haemathrin 2. The recombinant proteins, tyrosine-sulfated haemathrin 2 (haemathrin 2S), and WT haemathrin 2 were produced in Escherichia coli and subsequently purified and applied to SKOV3 and MDA-MB-231 cells with and without thrombin stimulation. Cell migration and invasion were assessed using wound healing and Transwell assays, respectively. Haemathrin 2S treatment significantly diminished cell migration and invasion promoted by thrombin in both SKOV3 and MDA-MB-231 cells (p < 0.05). Additionally, haemathrin 2S effectively inhibited thrombin-induced phosphorylation of serine/threonine kinase (Akt) in both cell lines (p < 0.05), while WT haemathrin 2 had this effect only in MDA-MB-231 cells. Furthermore, haemathrin 2S significantly reduced thrombin-activated phosphorylation of extracellular signal-regulated kinases (ERK) and p38 in both cell lines (p < 0.05) and reversed E/N-cadherin expression in thrombin-treated MDA-MB-231 cells (p < 0.05), which were not observed with WT haemathrin 2. Overall, haemathrin 2S was more effective than WT haemathrin 2 in reducing cancer cell migration and invasion, indicating that targeting thrombin with sulfated haemathrin is a promising strategy for cancer therapy. However, further in vivo studies are needed to confirm these results. Full article

The chemokine receptors CCR1 and CCR5 display overlapping expression patterns and ligand dependency. Here we find that ligand activation of CCR5, not CCR1, is dependent on N-terminal receptor O-glycosylation. Release from O-glycosylation dependency is obtained by increasing CCR5 N-terminus acidity to the level of CCR1. Ligand activation of CCR5, not CCR1, drastically improves in the absence of glycosaminoglycans (GAGs). Ligand activity at both CCR1 and CCR5 is boosted by positively charged/basic peptides shown to interact with acidic chemokine receptor N-termini. We propose that receptors with an inherent low N-terminus acidity rely on post-translational modifications (PTMs) to efficiently compete with acidic entities in the local environment for ligand capture. Although crucial for initial ligand binding, strong electrostatic interactions between the ligand and the receptor N-terminus may counteract following insertion of the ligand into the receptor binding pocket and activation, a process that seems to be aided in the presence of basic peptides. Basic peptides bind to the naked CCR1 N-terminus, not the CCR5 N-terminus, explaining the loss of boosting of ligand-induced signaling via CCR5 in cells incapable of glycosylation. Full article

Fucosylated chondroitin sulfate (FCS) was prepared from Bohadschia ocellata using protease hydrolysis. The structural characteristics of FCS were confirmed through chemical composition analysis using FTIR spectroscopy, ¹H NMR, and ¹³C NMR. FCS from B. ocellata (FCS-Bo) exhibited an average molecular weight of approximately 122 kDa. The biological activities of FCS-Bo, including anticoagulant, anti-cancer, and Protein Tyrosine Phosphatase 1B (PTP1B) inhibition, were evaluated. FCS-Bo displayed potent anticoagulant properties, markedly extending activated partial thromboplastin time, prothrombin time, and thrombin time when compared to the heparin control. In anti-cancer bioactivity research, FCS-Bo efficiently inhibited colony formation in the colon cancer cell lines HCT-116, HT-29, and DLD-1, achieving inhibition rates of up to 65%. Additionally, FCS-Bo exhibited significant inhibition of PTP1B, with an IC₅₀ as low as 0.0326 µg/mL, suggesting its potential for improving insulin sensitivity and managing conditions such as type 2 diabetes and obesity. Full article

Glycosaminoglycans (GAGs) and proteoglycans (PGs) are essential components of the extracellular matrix (ECM) with pivotal roles in cellular mechanosensing pathways. GAGs, such as heparan sulfate (HS) and chondroitin sulfate (CS), interact with various cell surface receptors, including integrins and receptor tyrosine kinases, to modulate cellular responses to mechanical stimuli. PGs, comprising a core protein with covalently attached GAG chains, serve as dynamic regulators of tissue mechanics and cell behavior, thereby playing a crucial role in maintaining tissue homeostasis. Dysregulation of GAG/PG-mediated mechanosensing pathways is implicated in numerous pathological conditions, including cancer and inflammation. Understanding the intricate mechanisms by which GAGs and PGs modulate cellular responses to mechanical forces holds promise for developing novel therapeutic strategies targeting mechanotransduction pathways in disease. This comprehensive overview underscores the importance of GAGs and PGs as key mediators of mechanosensing in maintaining tissue homeostasis and their potential as therapeutic targets for mitigating mechano-driven pathologies, focusing on cancer and inflammation. Full article

Deranged gut microbiota can release increased levels of uremic toxins leading to exacerbated kidney injury. In diabetic kidney disease (DKD), phenyl sulfate (PS) derived from tyrosine catabolism by gut microbiota has been demonstrated to be both an early diagnostic marker and a therapeutic target. In this perspective article, we summarize PS generation pathways and recent findings on PS and kidney injury in DKD. Increasing evidence has shown that the underlying mechanisms of PS-induced kidney injury mainly involve oxidative stress, redox imbalance, and mitochondrial dysfunction, which all may be targeted to attenuate PS-induced kidney injury. For future research directions, we think that a deeper understanding of the pathogenic role of PS in kidney injury using a variety of diabetic animal models should be investigated. Moreover, we also suggest beneficial approaches that could be used to mitigate the deleterious effect of PS on the kidney. These approaches include caloric restriction, tyrosine restriction, and administration of ketogenic drugs, ketogenic diets or natural products; all of which should be conducted under obese and diabetic conditions. Full article