Search Results (1,377)

Background: Against the backdrop of the large-scale and intensive development of the livestock industry, enhancing the reproductive efficiency of cattle has become a crucial factor in industrial development. Holstein cows, as the most predominant dairy cattle breed globally, are characterized by high milk yield and excellent milk quality. However, their reproductive efficiency is comprehensively influenced by a variety of complex factors, and improving their reproductive performance faces numerous challenges. The ovary, as the core organ of the female reproductive system, plays a decisive role in embryonic development and pregnancy maintenance. It is not only the site where eggs are produced and developed but it also regulates the cow’s estrous cycle, ovulation process, and the establishment and maintenance of pregnancy by secreting various hormones. The normal functioning of the ovary is crucial for the smooth development of the embryo and the successful maintenance of pregnancy. Methods: Currently, traditional sequencing technologies have obvious limitations in deciphering ovarian function and reproductive regulatory mechanisms. To overcome the bottlenecks of traditional sequencing technologies, this study selected Holstein cows as the research subjects. Ovarian samples were collected from one pregnant and one non-pregnant Holstein cow, and single-nucleus transcriptome sequencing technology was used to conduct an in-depth study on the ovarian cells of Holstein cows. Results: By constructing a cell type-specific molecular atlas of the ovaries, nine different cell types were successfully identified. This study compared the proportions of ovarian cell types under different physiological states and found that the proportion of endothelial cells decreased during pregnancy, while the proportions of granulosa cells and luteal cells increased significantly. In terms of functional enrichment analysis, oocytes during both pregnancy and non-pregnancy play roles in the “cell cycle” and “homologous recombination” pathways. However, non-pregnant oocytes are also involved in the “progesterone-mediated oocyte maturation” pathway. Luteal cells during pregnancy mainly function in the “cortisol synthesis and secretion” and “ovarian steroidogenesis” pathways; non-pregnant luteal cells are mainly enriched in pathway processes such as the “AMPK signaling pathway”, “pyrimidine metabolism”, and “nucleotide metabolism”. Cell communication analysis reveals that there are 51 signaling pathways involved in the pregnant ovary, with endothelial cells, granulosa cells, and luteal cells serving as the core communication hubs. In the non-pregnant ovary, there are 48 pathways, and the interaction between endothelial cells and stromal cells is the dominant mode. Conclusions: This study provides new insights into the regulatory mechanisms of reproductive efficiency in Holstein cows. The differences in the proportions of ovarian cell types, functional pathways, and cell communication patterns under different physiological states, especially the increase in the proportions of granulosa cells and luteal cells during pregnancy and the specificity of related functional pathways, indicate that these cells play a crucial role in the reproductive process of cows. These findings also highlight the importance of ovarian cells in pathways such as “cell cycle”, “homologous recombination”, and “progesterone-mediated oocyte maturation”, as well as the cell communication mechanisms in regulating ovarian function and reproductive performance. Full article

Rheumatoid arthritis (RA) is a chronic systemic inflammatory disorder primarily targeting joints, leading to pain, swelling, and stiffness. RA results from the body’s own immune system attacking its own tissues. Currently, there are various treatments available for RA including disease-modifying antirheumatic drugs (DMARDs) and NSAIDs. Leflunomide (LEF) is a USFDA-approved synthetic DMARD which is being widely prescribed for the management of RA; however, it faces several challenges such as prolonged drug elimination, hepatotoxicity, and others. LEF exerts its therapeutic effects by inhibiting dihydroorotate dehydrogenase (DHODH), thereby suppressing pyrimidine synthesis and modulating immune responses. Emerging nanotechnology-based therapies help in encountering the current challenges faced in LEF delivery to RA patients. This review enlists the LEF’s pharmacokinetics, mechanism of action, and clinical efficacy in RA management. A comparative analysis with methotrexate, biologics, and other targeted therapies, highlighting its role in monotherapy and combination regimens and the safety concerns, including hepatotoxicity, gastrointestinal effects, and teratogenicity, is discussed alongside recommended monitoring strategies. Additionally, emerging trends in novel formulations and drug delivery approaches are explored to enhance efficacy and minimize adverse effects. Overall, LEF remains a perfect remedy for RA patients, specifically individuals contraindicated with drugs like methotrexate. The therapeutic applicability of LEF could be enhanced by developing more customized treatments and advanced drug delivery approaches. 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

The paper proposes a putative prebiotic scenario leading to homochirality in the RNA world. In this scenario, racemic ribose, the only chiral moiety in RNA, was enantioseparated (in its pyranose form) on a chiral surface formed by the adsorption of (prochiral) nucleobases (NBs) on a mineral or metal. Purine bases (adenine and guanine) are more likely candidates for this process than pyrimidine bases because they have more H-bond donors and acceptors. Another possible candidate surface for the enantioseparation of ribose would be formed by the adsorption of nucleobase pairs, e.g., guanine–cytosine (GC). Interactions of ribose molecules with hydrogen bond donors and acceptors of NBs or NB pairs (located on the surface) enforced the orientation of ribose molecules in two directions perpendicular to each other and parallel to the surface. Consequently, the energy of interactions of enantiomers of the sugar with the surface was not the same. Thus, a solvent moving along the surface caused the enantiomers of ribose to move with different rates, resulting in the enantioseparation of ribose in a chromatography-like process. The same process would also separate ribose from other monosaccharides in the mix. Hydrogen bonding between nucleobases was also pivotal in the formation of large homochiral domains on the surfaces. Full article

This article presents a mini-review of the available data on the thermodynamics of the complexation of amino acids and peptides with some nucleic bases in a buffer medium. Data on changes in thermodynamic parameters (binding constants, Gibbs energy, enthalpy, entropy) during the complexation of nucleic bases with amino acids and peptides as a function of physicochemical properties are given at T = 298.15 K. The effects of complexation on the volumetric properties of nucleic bases, including apparent molar volumes, standard molar volumes, and limiting molar expansibility, over a temperature range of 288.15 to 313.15 K are considered in detail. Differences in the behavior of amino acids and peptides caused by different modes of coordination with nucleic bases are noted. These manifest in the stoichiometry of the formed complexes, the relationship with the acid dissociation constants of carboxyl and amino groups, enthalpy–entropy compensation in the complexation process, the temperature dependence of the transfer volumes, and the effect of hydrophobicity on volumetric characteristics. Full article

This study integrated non-targeted metabolomics and transcriptomics to investigate dynamic changes in Antheraea pernyi pupae across five developmental stages. Metabolomic analysis identified 1246 metabolites, primarily organic acids, lipids, heterocyclic compounds, and oxygen-containing organics. Principal component analysis revealed stage-specific metabolic profiles: amino acid derivatives (pyruvate, proline, lysine) declined, while pyrimidines (cytidine, uridine, β-alanine) and monosaccharides (glucose, mannose) increased. 18β-glycyrrhetinic and ursolic acids accumulated significantly in the middle and late stages. Transcriptomic analysis identified 7230 differentially expressed genes (DEGs), with 366, 1705, and 5159 significantly differentially expressed genes in the T1, T3, and T5 comparison groups, respectively. KEGG enrichment highlighted ABC transporters, amino acid/pyrimidine metabolism, and tyrosine pathways as developmentally critical, with aminoacyl-tRNA biosynthesis upregulated in later phases. Integrated multi-omics analysis revealed coordinated shifts in metabolites and genes across developmental phases, reflecting dynamic nutrient remodeling during pupal maturation. This study systematically delineates the molecular transitions driving pupal development in Antheraea pernyi pupae, uncovering conserved pathway interactions and mechanistic insights into nutrient metabolism. These findings provide a scientific foundation for leveraging pupal resources in functional food innovation and bioactive compound discovery for pharmaceutical applications. Full article

Dapagliflozin, a sodium-glucose cotransporter 2 inhibitor, treats type 2 diabetes by blocking renal glucose reabsorption and promoting urinary glucose excretion. This mechanism lowers blood glucose concentrations independently of insulin. The resulting caloric loss also contributes to weight reduction. Although these effects are well documented in patients with diabetes, their magnitude and underlying mechanisms in healthy individuals remain poorly understood. Background/Objectives: We investigated metabolic alterations after a single 10 mg dose of dapagliflozin in healthy adults with normal body-mass indices (BMIs) using untargeted metabolomics. Methods: Thirteen healthy volunteers completed this study. Plasma was collected before and 24 h after dosing. Untargeted metabolic profiling was performed with ultra-high-performance liquid chromatography–quadrupole time-of-flight/mass spectrometry. Results: Twenty-five endogenous metabolites were annotated; ten were putatively identified. Eight metabolites increased significantly, whereas two decreased. Up-regulated metabolites included phosphatidylcholine (PC) species (PC O-36:5, PC 36:3), phosphatidylserine (PS) species (PS 40:2, PS 40:3, PS 36:1, PS 40:4), lysophosphatidylserine 22:1, and uridine. Dehydroepiandrosterone sulfate and bilirubin were down-regulated. According to the Human Metabolome Database, these metabolites participate in glycerophospholipid, branched-chain amino acid, pyrimidine, and steroid-hormone metabolism. Conclusions: Dapagliflozin may affect pathways related to energy metabolism and homeostasis beyond glucose regulation. These data provide a reference for future investigations into energy balance and metabolic flexibility in metabolic disorders. Full article

This study reports an improved diastereoselective synthesis of substituted spiro[chromane-2,4′-pyrimidin]-2′(3′H)-ones via the acid-catalyzed condensation of 6-styryl-4-aryldihydropyrimidin-2-ones with resorcinol, 2-methylresorcinol, and pyrogallol. The optimized method allows for the isolation of diastereomerically pure products, with stereoselectivity controlled by varying acid catalysts (e.g., methanesulfonic acid vs. toluenesulfonic acid) and solvent conditions. The synthesized compounds were evaluated for antimicrobial and antioxidant activities. Notably, the (2S*,4R*,6′R*)-diastereomers exhibited significant antibacterial activity against both Gram-positive and Gram-negative bacterial strains with minimal inhibition concentration down to 2 µg/mL, while derivatives containing vicinal bisphenol moieties demonstrated potent antioxidant activity, with IC₅₀ values (12.5 µg/mL) comparable to ascorbic acid. Pharmacokinetic analysis of selected hit compounds revealed favorable drug-like properties, including high gastrointestinal absorption and blood-brain barrier permeability. These findings highlight the potential of spirochromane-pyrimidine hybrids as promising candidates for further development in the treatment of infectious diseases and oxidative stress-related pathologies. Full article

Nitrogen (N) critically regulates wheat growth and grain quality, yet the molecular mechanisms underlying foliar nitrogen application remain unclear. This study evaluated the effects of foliar nitrogen application (12.25 kg ha⁻¹) on the growth, grain yield, and quality of spring wheat, as well as its molecular mechanisms. The results indicated that N was absorbed within 3 h post-application, with leaf nitrogen concentration peaking at 12 h. The N treatment increased whole-plant dry matter accumulation and grain protein content by 11.34% and 6.8%, respectively. Amino acid content peaked 24 h post-application, increasing by 25.3% compared to the control. RNA-sequencing analysis identified 4559 and 3455 differentially expressed genes at 3 h and 24 h after urea treatment, respectively, these DEGs being primarily involved in nitrogen metabolism, photosynthetic carbon fixation, amino acid biosynthesis, antioxidant systems, and nucleotide biosynthesis. Notably, the plastidic glutamine synthetase gene (GS2) is crucial in the initial phase of urea application (3 h post-treatment). The pronounced downregulation of GS2 initiates a reconfiguration of nitrogen assimilation pathways. This downregulation impedes glutamine synthesis, resulting in a transient accumulation of free ammonia. In response to ammonia toxicity, the leaves promptly activate the GDH (glutamate dehydrogenase) pathway to facilitate the temporary translocation of ammonium. This compensatory mechanism suggests that GS2 downregulation may be a key switch that redirects nitrogen metabolism from the GS/GOGAT cycle to the GDH bypass. Additionally, the upregulation of the purine and pyrimidine metabolic routes channels nitrogen resources towards nucleic acid synthesis, and thereby supporting growth. Amino acids are then transported to the seeds, culminating in enhanced seed protein content. This research elucidates the molecular mechanisms underlying the foliar response to urea application, offering significant insights for further investigation. Full article

Background: Verticillium wilt (VW), caused by the fungal pathogen Verticillium dahliae, is a destructive disease that severely compromises cotton yield and fiber quality. Pyrimidine nucleotides, as essential metabolites and nucleic acid components, play critical roles in plant development and stress responses. However, genes involved in pyrimidine metabolism, especially their roles in disease resistance, remain largely uncharacterized in plants. Methods: Ghir_D05G039120, a gene encoding uridine kinase, shown to be associated with VW resistance in our previous study, was cloned and named as GhUKL4. The differential expression of GhUKL4 between the resistant and susceptible cultivars at multiple time points post-inoculation with V. dahliae was analyzed by quantitative real-time PCR (qRT-PCR), and the uracil phosphoribosyl transferase (UPRT) and uridine 5′-monophosphate kinase (UMPK) domains were verified by analyzing the amino acid sequences of GhUKL4. The role of GhUKL4 in the defense against VW infection was estimated by silencing GhUKL4 in the resistant and susceptible cultivars using virus-induced gene silencing (VIGS) analysis. Results: There were significant differences in the expression level of Ghir_D05G039120/ GhUKL4 among resistant and susceptible cotton lines. GhUKL4 contains UPRTase and UMPK domains, and there was one SNP between the resistant and susceptible cultivars in its 3′-UTR region. The silencing of GhUKL4 reduced cotton’s resistance to VW through mediating hormone signaling (JA) and oxidative stress (ROS) pathways. Conclusions: GhUKL4, encoding UMPK and UPRTase domain proteins, is a new regulatory factor associated with VW resistance in Gossypium hirsutum through fine-tuning JA-signalling and ROS bursting. Full article

The pyrrolo[2,3-d]pyrimidine (7-deazapurine) scaffold is a unique heterocyclic system included in the composition of most nucleotides. In this study, series of the pyrrolo[2,3-d]pyrimidine-imines and 3-halo-substituted pyrrolo[2,3-d]pyrimidines were designed and prepared in high yields. Condensed pyrimidines are obtained via carbonyl-amine condensation and carbon-halogen bond formation. Pyrrolo[2,3-d]pyrimidine-imines containing a bromine substituent at position C-4 of the phenyl ring and azepine side-ring exhibited superior antitumor activity on the colon cancer HT-29 cell line; IC₅₀ values were 4.55 and 4.01 µM, respectively. These results revealed an interesting pattern, where condensed pyrimidinones containing an azepine ring demonstrated selective antitumor activity on the colon cancer cell line HT-29. In addition, the molecular docking results suggest that compound 8g provided a thorough understanding of its interactions with the DDR2 active site. This could pave the way for further development and optimization of DDR-targeting drugs, contributing to advancements in cancer therapeutics. This lead compound may serve as design templates for further studies. Full article

Helicobacter pylori is a gastric pathogen implicated in peptic ulcer disease and gastric cancer. The increasing prevalence of antibiotic-resistant strains underscores the urgent need for alternative therapeutic strategies. In this study, we investigated the chemical composition and antibacterial activity of an aqueous extract from Caulerpa lentillifera (sea grape), a farm-cultivated edible green seaweed collected from Krabi Province, Thailand. Ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS) revealed that the extract was enriched in bioactive nucleosides and phenolic compounds. In vitro assays demonstrated dose-dependent inhibition of H. pylori growth following exposure to sea grape extract. Furthermore, untargeted intracellular metabolomic profiling of H. pylori cells treated with the extract uncovered significant perturbations in central carbon and nitrogen metabolism, including pathways associated with the tricarboxylic acid (TCA) cycle, one-carbon metabolism, and alanine, aspartate, and glutamate metabolism. Pyrimidine biosynthesis was selectively upregulated, indicating a potential stress-induced shift toward nucleotide salvage and DNA repair. Of particular note, succinate levels were markedly reduced despite accumulation of other TCA intermediates, suggesting disruption of electron transport-linked respiration. These findings suggest that bioactive metabolites from C. lentillifera impair essential metabolic processes in H. pylori, highlighting its potential as a natural source of antimicrobial agents targeting bacterial physiology. Full article

This study describes the synthesis of heterocyclic derivatives containing multiple nitrogen atoms serving as important moieties for developing novel antidiabetics through a simple synthetic pathway. We herein describe the synthesis and characterization of novel pyrimidine derivatives using one-pot reactions in a catalyst-free and efficient manner through a two-stage process involving the synthesis of 2-amino-4-hydrazinyl-6-methoxy pyrimidine, followed by a reaction with phenyl isothiocyanate derivatives. The structures of all the new compounds were confirmed via physical and spectral analysis. Furthermore, we evaluated the synthesized pyrimidine derivatives’ biological activities in relation to their potential roles as novel anti-diabetic agents by testing their activity profiles against the enzymes α-glucosidase and α-amylase. Compound 4 expressed the highest level of activity against α-glucosidase and α-amylase, with a greater inhibitory concentration (IC₅₀ of 12.16 ± 0.12 µM and IC₅₀ 11.13 ± 0.12 µM) compared to that of acarbose (IC₅₀ = 10.60 ± 0.17 µM and IC₅₀ = 11.30 ± 0.12 µM), which is widely used as a standard antidiabetic drug. The primary structure activity relationship analysis identified the impact of an electron- withdrawing group, especially with respect to fluorine on inhibitory activity. This was further confirmed in molecular docking studies, which demonstrated that both compounds exhibited similar inhibition patterns and emphasized the significance of incorporating a lipophilic electron-withdrawing substituent on the phenyl ring, along with the 2,4-diaminopyrimidine scaffold. 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

The synthesis of various heterocyclic base modifications of nucleic acids has been thoroughly investigated; however, much less is known about their catabolism. Also, little is known about the transport of such compounds across the microbial cell membranes. Using the Saccharomyces cerevisiae single-gene deletion library, we performed genome-wide screening for genes affecting the growth of yeast in minimal media supplemented with N⁴-acetylcytosine as a source of uracil. We found that Fcy1, Fcy21, Bud16, Gnd1, and Fur4 proteins are required for efficient growth in the tested medium. Additionally, we used several heterocyclic pyrimidine bases and Fcy homolog mutants to test their growth in respective minimal media. We found that tested permeases differently affect the growth of yeast that is dependent on the heterocyclic pyrimidine bases used as a source of uracil. The most pronounced effect was observed for the ∆fur4 mutant, which was growing much slower than the corresponding wild-type strain in the media supplemented with N⁴-acetylcytosine, 4-methylthiouracil, N⁴-methylcytosine, N⁴,N⁴-dimethylcytosine, 2-thiouracil, or 4-thiouracil. We suggest that Fur4 protein is the major yeast transporter of modified heterocyclic pyrimidine bases. Our observations might be helpful when investigating the actions of various heterocyclic base-based antifungal, anticancer, and antiviral drugs. Full article