Search Results (174)

This story began half a century ago with the discovery of an unusually high presence of tryptophan (Trp, W) in transthyretin (TTR), one of the three carrier proteins of thyroid hormones. With the Trp-rich retinol-binding protein (RBP), TTR forms a plasma complex implicated in the delivery of retinoid compounds to body tissues. W has the lowest concentration among all AAs involved in the sequencing of human body proteins. The present review proposes molecular maps focusing on the ratio of W/AA residues found in the sequence of proteins involved in immune events, allowing us to ascribe the guidance of inflammatory processes as fully under the influence of W. Under the control of cytokine stimulation, plasma biomarkers of protein nutritional status work in concert with major acute-phase reactants (APRs) and with carrier proteins to release, in a free and active form, their W and hormonal ligands, interacting to generate hot spots affecting the course of acute stress disorders. The prognostic inflammatory and nutritional index (PINI) scoring formula contributes to identifying the respective roles played by each of the components prevailing during the progression of the disease. Glucagon demonstrates ambivalent properties, remaining passive under steady-state conditions while displaying stronger effects after cytokine activation. In developing countries, inappropriate weaning periods lead to toddlers eating W-deficient cereals as a staple, causing a dramatic reduction in the levels of W-rich biomarkers in plasma, constituting a novel nutritional deficiency at the global scale. Appropriate counseling should be set up using W implementations to cover the weaning period and extended until school age. In adult and elderly subjects, the helpful immune protections provided by W may be hindered by the surge in harmful catabolites with the occurrence of chronic complications, which can have a significant public health impact but lack the uncontrolled surges in PINI observed in young infants and teenagers. Biomarkers of neurodegenerative and neoplastic disorders measured in elderly patients indicate the slow-moving elevation of APRs due to rampant degradation processes. Full article

This study describes the first complete genomic sequence of an NDM-19 and QnrS11-producing multidrug-resistant (MDR) Escherichia coli isolate collected from a fecal swab from a poultry farm in 2019 in Egypt. The bla_NDM-19 was identified by PCR screening and DNA sequencing. The isolate was then subjected to antimicrobial susceptibility testing, conjugation and transformation experiments, and complete genome sequencing. The chromosome of strain M2-13-1 measures 4,738,278 bp and encodes 4557 predicted genes, with an average G + C content of 50.8%. M2-13-1 is classified under ST167, serotype O101:H5, phylogroup A, and shows an MDR phenotype, having minimum inhibitory concentrations (MICs) of 64 mg/L for both meropenem and doripenem. The genes bla_NDM-19 and qnrS11 are present on 49,816 bp IncX3 and 113,285 bp IncFII: IncFIB plasmids, respectively. M2-13-1 harbors genes that impart resistance to sulfonamides (sul1), trimethoprim (dfrA14), β-lactams (bla_TEM-1B), aminoglycosides (aph(6)-Id, aph(3′)-Ia, aph(3″)-Ib, aac(3)-IV, and aph(4)-Ia), tetracycline (tet(A)), and chloramphenicol (floR). It was susceptible to aztreonam, colistin, fosfomycin, and tigecycline. The genetic context surrounding bla_NDM-19 includes ISAba125-IS5-bla_NDM-19-ble_MBL-trpF-hp1-hp2-IS26. Hierarchical clustering of the core genome MLST (HierCC) indicated M2-13-1 clusters with global ST167 E. coli lineages, showing HC levels of 100 (HC100) core genome allelic differences. Plasmids of the IncX3 group and the insertion sequence (ISAba125) are critical vehicles for the dissemination of bla_NDM and its related variants. To our knowledge, this is the first genomic report of a bla_NDM-19/IncX3-carrying E. coli isolate of animal origin globally. Full article

Background/Objectives: Gut-derived tryptophan (Trp) metabolites play important roles in metabolic and cardiovascular regulation. Although animal studies suggest their protective effects against metabolic dysfunction, data in adolescents, particularly those with obesity, remain limited. The objective of this study was to evaluate associations between circulating gut-derived Trp metabolites and markers of cardiometabolic, vascular, and platelet health in adolescents with obesity. Methods: Data were analyzed from 28 adolescents (ages 13–18; mean BMI = 36 ± 6.4 kg/m²). Fasting blood was collected to assess lipid profiles using a clinical analyzer and insulin resistance using the homeostatic model assessment for insulin resistance (HOMA-IR). Gut-derived Trp metabolites were measured by UPLC–mass spectrometry, peak oxygen uptake (VO_{2 peak}) by gas exchange during an incremental cycle ergometer test, and body composition by dual-energy X-ray absorptiometry. Platelet spare respiratory capacity (SRC), endothelial function, and liver fat were measured using high-resolution respirometry, flow-mediated dilation (FMD) of the brachial artery, and magnetic resonance imaging respectively. Results: Indole-3-propionic acid was inversely associated with diastolic blood pressure (rho = −0.39, p = 0.047), total cholesterol (rho = −0.55, p = 0.002), and LDL-C (rho = −0.57, p = 0.0014), independent of sex and obesity severity. Indoxyl sulfate was positively correlated with fasting glucose (rho = 0.47, p = 0.012), and adolescents with impaired fasting glucose had 1.6-fold higher IS levels. Indole-3-acetaldehyde declined with age (rho = −0.50, p = 0.007), and Indole-3-acetic acid and indole were higher in Hispanics vs. non-Hispanics. No significant associations were observed between Trp metabolites and FMD, VO₂ peak, or SRC. Conclusions: Gut-derived Trp metabolites, particularly indole-3-propionic and indoxyl sulfate, are associated with markers of cardiometabolic risk in adolescents with obesity. These findings support their potential relevance in early-onset cardiovascular disease risk. Full article

Diabetic wounds are a devastating complication that cause chronic pain, recurrent infections, and limb amputations due to impaired healing. Despite advances in wound care, existing therapies often fail to address the underlying molecular dysregulation, highlighting the need for innovative and safe therapeutic approaches. Among these, D-amino acids such as D-tryptophan (D-Trp) have emerged as key regulators of cellular processes; however, their therapeutic potential in diabetic wounds remains largely unexplored. Here, we investigate the therapeutic potential of D-Trp in streptozotocin (STZ)-induced diabetic mice, comparing it with phosphate-buffered saline (PBS) controls and vascular endothelial growth factor (VEGF) as a positive control. Wound healing, inflammation, and histopathology were assessed. Protein and gene expression were analyzed via Western blot and RT-qPCR, respectively. Biolayer interferometry (BLI) measured the binding of D-Trp to hypoxia-inducible factor-1α (HIF-1α). D-Trp accelerated wound healing by modulating extracellular matrix (ECM) remodeling, signaling, and apoptosis. It upregulated matrix metalloproteinases (MMP1, MMP3, MMP-9), Janus kinase 2 (JAK2), and mitogen-activated protein kinase (MAPK) proteins while reducing pro-inflammatory cytokines (tumor necrosis factor-α [TNF-α], interleukin-1β [IL-1β], IL-6). D-Trp also suppressed caspase-3 and enhanced angiogenesis through HIF-1α activation. These findings suggest that D-Trp promotes healing by boosting ECM turnover, reducing inflammation, and activating MAPK/JAK pathways. Thus, D-Trp is a promising therapeutic for diabetic wounds. Full article

Shelter environments can be inherently stressful for dogs, a highly social species that forms strong attachment bond with humans. This study evaluated stress responses in 26 shelter dogs during routine veterinary examinations, analyzing behavioral scores alongside physiological and hormonal parameters, including heart rate, body temperature, cortisol (CRT), oxytocin (OXT), serotonin (5-HT), tryptophan (TRP), and interleukin-6 (IL-6). A significant negative correlation was observed between OXT and CRT (ρ = –0.540, p = 0.007), particularly in dogs exhibiting relaxed behavior. OXT was also negatively correlated with body temperature (ρ = –0.435, p = 0.034), supporting its potential role in modulating stress-induced hyperthermia. No significant associations were found between TRP, 5-HT, IL-6, or other physiological measures and behavioral scores. The absence of correlation between TRP and 5-HT may be due to blood–brain barrier regulation, while IL-6′s lack of association suggests further investigation is needed to clarify its role in canine stress responses. These findings highlight OXT’s possible buffering effect on the hypothalamic–pituitary–adrenal axis and suggest that behavioral assessment may offer a more sensitive measure of canine stress than hormonal or physiological parameters alone. Future studies with larger and more diverse samples are needed to confirm and expand upon these results. Full article

Chiral analysis is becoming increasingly important across various scientific fields, including chemistry, pharmaceuticals, biosciences, and more recently, metabolomics. In this context, a high-resolution and high-throughput method was developed for the simultaneous determination of the enantiomeric ratio (er) of seven pairs of amino acid (AA) enantiomers (Arg, Gln, His, Met, Pro, Tyr, and Trp) using flow injection analysis coupled with ion mobility-mass spectrometry (FIA-IM-MS) technology. Specifically, the Single Ion Mobility Monitoring (SIM²) mode on a TIMS-Tof^TM instrument enabled the rapid relative quantification of chiral compound mixtures. A linear model accurately described the relationship between enantiomeric ratio and IM-MS response for Arg, Gln, and Pro enantiomers, as evidenced by high R² values and unbiased residuals. In contrast, non-linear trends were observed for His, Tyr, and Trp, where a quadratic model significantly improved the fit. However, the linear model was retained for Met, despite an R² of about 0.98, due to its comparable performance and simplicity. Measurement accuracy was confirmed with very good recovery rates for er values of 0.95 and 0.99 across all AAs. Finally, the potential of the FIA-SIM²-MS approach in chiral analysis was demonstrated, particularly its ability to provide a reliable and efficient high-throughput tool for accurate er determination. Full article

The functional properties of proteins are closely related to their structure and conformation. The effects of glycosylation and pH on the structural and conformational changes in whey protein isolate (WPI) were investigated using multispectral technology. More and higher-molecular-weight molecules of WPI–dextran conjugates (WDCs) with increased degrees of glycosylation (DGs) in SDS-PAGE occurred at the expense of band intensities of α-lactalbumin, β-lactoglobulin, and bovine serum albumin. The higher wavenumber shift in FTIR peaks of WPI after glycosylation in the Amide I, II, and III regions and the decrease in its intensity occurred. The maximum absorption wavelength (λ_max) of UV-Vis spectra of WPI before and after glycosylation in the range of 260–290 nm showed no significant difference in a pH range of 2.0–10.0. Moreover, the UV-Vis absorption intensities of WDCs at λ_max around 278 nm were highly and positively correlated with their DGs. The λ_max and intensities of total intrinsic fluorescence spectra of Tyr and Trp residues in WDCs with an increase in DGs had an obvious redshift and decrease, respectively. Although the intensities of synchronous fluorescence spectra of individual Tyr or Trp residues in WDCs with an increase in DGs also gradually decreased, the λ_max of the former and latter had a blueshift and redshift, respectively. UV-Vis absorption and fluorescence spectroscopies indicated that the changes in the λ_max and intensity of WPI were closely related to the protonation states of carbonyl groups and free amino groups and the degree of glycosylation. This work may be beneficial for understanding the structural and conformational changes in proteins by measuring the microenvironment around Tyr and/or Trp residues in proteins using UV-Vis absorption and synchronous fluorescence spectroscopies, providing a promising technique for quantitatively monitoring the degree of glycosylation (DG) in a rapid and practical way without any chemical reagents using UV-Vis absorption spectroscopy. Full article

Excessive melanogenesis causes abnormal pigmentation and a higher risk of skin disorders (e.g., melanoma). Resveratrol (RSV), a natural polyphenol, exerts antioxidant and anti-aging effects. However, the effects of RSV and its derivatives on melanogenesis remain unclear. This study investigated their effects on melanogenesis and antioxidant activity in B16F10 cells. After measuring cell viability, B16F10 cells were incubated with 50 µM of RSV, dihydroresveratrol (DIRSV), and other RSV derivatives for 24 h. The relative melanin content and tyrosinase activity were quantified. The protein and mRNA levels of melanogenesis-related genes (MITF, CREB, TYR, and TRP) and the binding affinity of RSV derivatives to their target proteins were measured. The antioxidant activity was evaluated using ABTS and DPPH assays. RSV and DIRSV (50 µM) significantly reduced melanin content and tyrosinase activity, respectively. However, other derivatives had no significant effects. RSV, DIRSV, and other derivatives significantly suppressed MITF and CREB levels. Additionally, DIRSV significantly reduced p-CREB and TYR protein levels and showed a higher affinity for CREB than RSV, despite no significant changes in MITF, TYR, or TRP mRNA levels. In the antioxidant assays, RSV and DIRSV exhibited significant ABTS and DPPH radical scavenging activities. DIRSV, like RSV, inhibits melanogenesis and exhibits antioxidant effects in B16F10 cells. However, RSV derivatives demonstrate partial antioxidant activity and inhibit melanogenesis-related proteins but do not significantly affect melanogenesis. DIRSV’s practical applications as a skin-protective and -whitening agent warrant further exploration. Full article

Over-the-air (OTA) testing is crucial for optimizing wireless performance of 5G smart watches and improving their user experience. However, the current required test time is so long that it is almost impossible to complete the entire OTA testing without recharging and repositioning, which is unacceptable for the industry. Therefore, test-time reduction is significant. The objective of this work is to optimize measurement grids for OTA testing of 5G smart watches, which balance accuracy with efficiency. In this research, passive patterns from a typical 5G commercial smart watch are measured at different bands as reference patterns, which represent general radiation properties of 5G commercial smart watches. The effect of various coarse grids on OTA testing precision is characterized quantitatively by analyzing their accuracy in reconstructing reference patterns. The related measurement uncertainty (MU) terms are then evaluated and determined quantitatively based on statistical analysis. According to the derived MU limits for grid configurations, reducing grid points from currently required 62 (30/30) to 26 (45/45), and from 266 (15/15) to 62 (30/30) could save roughly 60% and 75% of the test time, respectively, with an uncertainty increase of 0.1 dB for both Total Isotropic Sensitivity (TIS) and Total Radiated Power (TRP) testing, which is considered acceptable. Furthermore, the feasibility of the proposed MU analysis and recommended grids have been experimentally verified. Full article

Amaranthus palmeri is a highly problematic agricultural weed due to its rapid growth, high seed production, and strong tendency to develop herbicide resistance. In Spain, the initial colonization of A. palmeri began in 2007, when populations were detected at various locations in the province of Lleida (Catalonia). Since then, new infestations have been reported in other regions of the country, primarily infesting maize fields. Although resistance to glyphosate or to acetolactate synthase (ALS) inhibitors has been documented in several populations from Catalonia and Extremadura, little is known about the resistance profile of populations from Aragon. The main objective of this study was to characterize the putative resistance of five populations from Aragon to 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) inhibitors (glyphosate) and ALS inhibitors (nicosulfuron and imazamox). Sensitivity to both mechanisms of action was measured by root growth in vertical plates and shikimate accumulation for glyphosate. Target-site resistance was evaluated by analyzing EPSPS and ALS gene copy numbers and ALS gene mutations. The populations showed high variability, with no multiple resistance detected. The Bujaraloz population showed moderate resistance to glyphosate due to EPSPS gene amplification. In three populations, mutations in the ALS gene conferring resistance were detected. The Trp574Leu mutation was detected in approximately half of the individuals from the Albelda, Tamarite de Litera, and Caspe populations. In the latter, the Pro197Thr mutation was also present. This study reveals significant genetic variability within each population and provides evidence for the spread of herbicide resistance across different regions of Spain. Full article

Background: The kynurenine (KYN) pathway of tryptophan metabolism has been linked to inflammation and cardiovascular risk, but its long-term prognostic value remains unclear. Methods: We analyzed 492 patients from the KORONEF registry who underwent coronary and renal angiography and were followed for a median of 10.2 years. Plasma levels of tryptophan (TRP), KYN, and downstream metabolites were measured. The primary endpoint was all-cause mortality. Results: The mean age was 64.4 ± 9.9 years, and 37.2% of patients were female. Common comorbidities included hypertension (74.8%), dyslipidemia (46.0%), and diabetes (25.8%). Overall mortality reached 29.5% and increased across KYN tertiles: 17.6% (T1), 28.2% (T2), and 42.9% (T3) (p < 0.001). In a multivariable Cox analysis, KYN independently predicted mortality (HR: 1.79; 95% CI: 1.15–2.44; p < 0.001), alongside age, diabetes, prior myocardial infarction, chronic kidney disease, and left ventricular ejection fraction. Other kynurenine pathway metabolites were not independently associated with outcomes. Conclusions: Elevated kynurenine levels independently predict 10-year all-cause mortality in patients undergoing coronary angiography. KYN may represent a useful prognostic biomarker beyond traditional clinical and angiographic variables. Full article

PD-L1 (programmed cell death ligand-1) is a protein located on the surface of regulatory cells. It has an immunosuppressive role as it binds specifically to the protein programmed cell death-1 (PD-1), a checkpoint glycoprotein, present on the surface of immune cells such as T and B lymphocytes. Many tumor cells block the immune response by overexpressing PD-L1 on their surface; therefore, targeting PD-L1 represents a powerful strategy that allows tumor localization. To determine the presence of PD-L1 in cells, the use of ad hoc functionalized peptides that bind to PD-L1 can be exploited. One of them is the peptide CLP002 (Trp-His-Arg-Ser-Tyr-Tyr-Thr-Trp-Asn-Leu-Asn-Thr), which, bound to surface-enhanced Raman scattering (SERS) gold nanostructures via a suitable linker, was shown to be highly effective in recognizing MDA-MB-231 breast cancer cells and, importantly, this recognition can be measured by SERS experiments. To characterize, on a molecular scale, the interaction between PD-L1 and peptide functionalized nanostructures, we performed molecular dynamics (MDs) simulations, studying the features of peptide monolayers bound on gold surfaces in the absence and presence of PD-L1. The results obtained allow us to explain why the nature of the linker plays a fundamental role in the binding and why a peptide carrying the same amino acids as CPL002 but with a different sequence (scrambled) is much less active than CLP002. These results open the way to an in silico evaluation of the key parameters that regulate the binding of PD-L1 useful for cancer recognition. Full article

The study of solid–liquid equilibria in small molecules such as l-tryptophan (l-Trp), which possesses an α-amino group, an α-carboxylic acid group, and an indole compound, presents significant challenges. This research introduces several findings aimed at enhancing process efficiency and sustainability in downstream processing of l-Trp from fermentative origin via crystallization. Transitioning from batch to continuous processes allows for improved scalability and resource management. Furthermore, solubility measurements combined with thermodynamic data from the literature will provide deeper insights into molecular interactions and allow for systematic and data-driven process design. Lab-scale crystallization experiments in both batch and continuous operation allow for the assessment of the process feasibility and solvent impacts on the process and product. The focus is on process development that emphasizes material savings through strategic solvent selection and co-solvent choices. Full article

Background/Objectives: This study aims to investigate the effects of 5,7-dihydroxy-4-methylcoumarin (5,7D-4MC) on melanogenesis in B16F10 murine melanoma cells and to evaluate its safety as a potential ingredient for functional cosmetics and therapeutic agents targeting pigmentation-related disorders. Method: The cytotoxicity of 5,7D-4MC was assessed using an MTT assay, and melanin content and tyrosinase activity were measured at different concentrations (25, 50, 100 µM). Western blot analyses were conducted to evaluate the expression of key melanogenesis-related proteins (TYR, TRP-1, TRP-2, and MITF) and to investigate the regulation of major signaling pathways, including PKA/cAMP, GSK3β, and PI3K/AKT. Additionally, a human primary skin irritation test was performed on 32 participants to assess the dermatological safety of 5,7D-4MC. Results: 5,7D-4MC did not affect cell viability at concentrations below 100 µM and significantly promoted melanin production in a dose-dependent manner. Tyrosinase activity and the expression levels of melanogenic proteins increased significantly following 5,7D-4MC treatment. PKA and GSK3β pathways were activated, while the PI3K/AKT pathway was downregulated. The skin irritation test showed that 5,7D-4MC exhibited low irritation potential at concentrations of 50 µM and 100 µM. Conclusions: 5,7D-4MC enhances melanogenesis and demonstrates low skin irritation, making it a promising candidate for therapeutic applications in treating hypopigmentation disorders, such as vitiligo, as well as a functional cosmetic ingredient. However, further studies involving human melanocytes and clinical trials are required to validate their efficacy. Full article

Objectives: The aim was to simultaneously investigate inflammatory biomarkers, neopterin, the kynurenine/tryptophan (Kyn/Trp) pathway, vitamin D (VitD), vitamin D binding protein (VDBP), and erythrocyte folate, in cerebral palsy (CP). Methods: A case–control study was conducted at Mersin University Hospital. Three- to ten-year-old patients with spastic CP (n = 50) and age- and gender-matched healthy controls (n = 55) were included. Serum levels of neopterin, Trp, Kyn and 25OHD, plasma VDBP, and erythrocyte folate concentrations were measured. Indoleamine-2,3-dioxygenase 1 (IDO-1) enzyme activity was evaluated according to the Kyn/Trp ratio. Comparison and correlation analyses were performed. Results: The levels of neopterin, Trp, and Kyn were lower in children with CP than in healthy controls (p = 0.037, p < 0.001, and p = 0.003, respectively). IDO1 was not significantly different between the CP and control groups (p = 0.214). The levels of VitD and VDBP were higher in children with CP (p < 0.001 and p = 0.001, respectively). The level of erythrocyte folate was also higher in children with CP (p < 0.001). No significant correlation was found between age and inflammatory biomarkers in the CP group. Neopterin was correlated with the level of Gross Motor Function Classification System (GMFCS) level (r = 0.292, p = 0.044), while there was no significant correlation between the other biomarkers and the level of GMFCS in the CP group. Conclusions: Inflammatory biomarkers of neopterin and Kyn are lower, inflammatory biomarkers of VDBP and erythrocyte folate are higher, and anti-inflammatory VitD is higher in children with spastic CP compared to healthy children. More knowledge is needed to demonstrate inflammatory and anti-inflammatory status in children with CP. Full article