课程文献中心 更多>>

关键词： Cold-active   GH64   Glucanase   Laminaripentaose   Structural analysis  

摘要： β-1,3-Glucans are ubiquitous polysaccharides whose enzymatic hydrolysis yields β-1,3-gluco-oligosaccharides (GOS) with immunomodulatory, antioxidant, and prebiotic properties. These bioactivities highlight their potential as functional food ingredients. However, conventional enzymatic methods often yield structurally heterogeneous GOS, complicating their application. Glycoside hydrolase family 64 (GH64) enzymes are unique in producing laminaripentaose as a single dominant product, enabling the preparation of structurally uniform GOS. Here, a novel GH64 enzyme, CsGH64, from Candidatus saccharibacteria was biochemically and structurally characterized. CsGH64 exhibited strict β-1,3-glucanase activity, producing laminaripentaose at > 80% yield, with optimal activity at pH 6.0 and 20 °C. Kinetic analysis revealed a Km of 27.9 mg mL⁻¹ and a Vmax of 16.3 U mg⁻¹. Comparative structural analysis with previously characterized GH64 enzymes uncovered distinct features underlying its cold-adapted catalytic properties. These results identify CsGH64 as a promising biocatalyst for the food and nutraceutical industries, enabling the efficient and mild production of structurally defined, bioactive oligosaccharides.

摘要： Renal fibrosis is the hallmark pathological outcome of chronic kidney disease (CKD), and effective anti-fibrotic therapies remain scarce. This study investigates the renoprotective effects and underlying mechanisms of emodin. A rat model of renal fibrosis was established using doxorubicin hydrochloride (DXR, 4 mg/kg), and NRK-52E cells were treated with angiotensin II (Ang II, 1 μM) to induce renal fibrosis in vitro. The regulatory effects of emodin (oral gavage of 40 mg/kg/day for 4 weeks in vivo and 100 μmol/L in vitro) on renal dysfunction, fibrosis, oxidative stress, and pyroptosis were evaluated. Additionally, the role of emodin in mediating the 5-methylcytosine (m⁵C) modification of transient receptor potential vanilloid 4 (TRPV4) was investigated in vitro. The interaction between emodin and the m⁵C regulatory protein AlkB homolog 1 (ALKBH1), as well as the association between ALKBH1 and TRPV4 mRNA, were detected. Emodin significantly ameliorated renal dysfunction and attenuated fibrosis in DXR-induced rats. Emodin also restored TRPV4 expression, which was downregulated in the fibrotic models. Conversely, TRPV4 knockdown partially reversed the protective effects of emodin, leading to exacerbated activation of the transforming growth factor-β1 (TGF-β1)/Smad2/3 pathway, along with enhanced fibrosis and pyroptosis. Mechanistically, Ang II elevated global m⁵C RNA modification and upregulated the demethylase ALKBH1; these effects were reversed by emodin. Furthermore, ALKBH1 overexpression promoted the destabilization of TRPV4 mRNA via site-specific m⁵C demethylation. Emodin alleviates renal fibrosis by preserving TRPV4 expression through targeting the ALKBH1-dependent m⁵C demethylation axis. Targeting the ALKBH1–m⁵C–TRPV4 axis may represent a promising therapeutic strategy for renal fibrosis.

关键词： Complex   Crystal structure   Fluorescence sensor  

摘要： In this paper, 3, 5-bis-(triazol-1-yl)-benzoic acid (HL1) and 2, 4-bis-(triazol-1-yl)-benzoic acid (HL2) are used as ligands to obtain two complexes of [Zn(L1)₂]∙0.25H₂O (1) and [Zn₂(L2)₄] (2). Single crystal X-ray diffraction analysis shows that complex 1 forms a three-dimensional structure similar to the interlocking zipper, and complex 2 exhibits an occlusal two-dimensional framework with cavities. The solid-state fluorescence properties of complexes 1–2 were further investigated to explore their applications. The results show that the fluorescence of these two complexes are very different, in which 1 displays very impressive fluorescence compared with 2. Thus, complex 1 was further studied as a chemical sensor and it is interesting to find that this complex can be used to detect Cr₂O₇²⁻ (LOD: 1.29 μM) by fluorescence quenching and DMSO by fluorescence enhancement. At the same time, complex 1 also has fluorescence enhancement effect in the related cation sensing experiments. On the basis of these experiments, the fluorescence quenching mechanism was also screened, and the energy transfer between the analyte and the complex is the main point of fluorescence quenching. In addition, to explore the extendable properties of the complexes, the dye adsorption experiments were also carried out. Interestingly, complex 2 displays certain adsorption capacity for different types of organic dyes of CR, MG, CV, MB, FY and OG within 30 min.

关键词： Alzheimer’s disease   Cognitive deficits   NPY4/GLP-1   Neuroinflammation   cGAS-STING  

摘要： Effective disease-modifying therapies for Alzheimer’s disease (AD) remain limited. Glucagon-like peptide-1 receptor (GLP-1R) activation has shown neuroprotective potential in AD, whereas the neuropeptide Y/pancreatic polypeptide-Y4 receptor (NPY/PP-Y4R) axis has been implicated in central homeostasis and inflammatory regulation, although its role in AD remains insufficiently defined. Here, we evaluated a rationally designed bifunctional peptide predicted to target both NPY4R and GLP-1R in 5 × FAD mice and LPS-stimulated BV2 cells. In vivo, NPY4/GLP-1 improved spatial learning and memory, working memory, and exploratory behavior, and was accompanied by reduced hippocampal Aβ burden (P < 0.05), alleviated neuronal injury (P < 0.01), improved synaptic integrity (P < 0.01), and attenuated mitochondrial abnormalities (P < 0.01). These changes were associated with lower hippocampal levels of cytosolic mitochondrial DNA (mtDNA) (P < 0.05), cGAS (P < 0.05), STING (P < 0.05), and phosphorylated IRF3 (P < 0.01), together with decreased IL-1β (P < 0.05) and increased IL-10 (P < 0.05) expression. In LPS-stimulated BV2 cells, NPY4/GLP-1 similarly reduced STING-related signaling (P < 0.05) and inflammatory responses (P < 0.05). Co-treatment with the STING inhibitor C-176 provided additional support for the involvement of STING-associated inflammatory signaling under in vitro inflammatory conditions. Molecular docking suggested that NPY4/GLP-1 may interact with both NPY4R and GLP-1R, providing a structural rationale for its bifunctional design. Collectively, these findings indicate that NPY4/GLP-1 exerts beneficial effects in AD-related models and that these effects are associated with attenuation of mtDNA-cGAS-STING-related neuroinflammatory signaling. This study provides initial evidence supporting further evaluation of this nov

摘要： Tris(1,3-dichloro-2-propyl) phosphate (TDCPP) is a widely used organophosphate flame retardant that is ubiquitously detected in environmental matrices and human biological samples, raising concerns about its potential health risks. However, the mechanisms underlying TDCPP-induced hepatotoxicity remain incompletely understood. Here, we investigated the hepatic effects of TDCPP using an integrated in vivo–in vitro approach combining a mouse exposure model, human-derived 3D liver organoids, and network toxicology analysis.

摘要： The authors regret © 2026 Elsevier B.V.

关键词： Ficus carica   Gene expression   Hormone interaction   Postharvest ripening  

摘要： The role of 1-methylcyclopropene (1-MCP) in regulating polyamine (PA) and ethylene metabolism in cold-stored fig fruit was investigated. ‘Brown Turkey’ figs were packaged in polyethylene (PE) bags with or without 1-MCP sachets (control) and stored at 1 ± 0.5 °C. Compared with controls, 1-MCP application generally delayed the decrease in respiratory rate, enhanced ethylene generation, reduced 1-aminocyclopropane-1-carboxylic acid (ACC) and S-adenosyl methionine (SAM) contents, and increased 1-malonylamino-ACC (MACC) and decarboxylated SAM (dcSAM) contents during storage. This treatment increased putrescine (Put) and spermine (Spm) contents but decreased spermidine (Spd) content during early storage. The activities of polyamine oxidase (PAO), arginine decarboxylase (ADC) and diamine oxidase (DAO) were increased by exogenous 1-MCP during late storage, while the activity of ornithine decarboxylase (ODC) was enhanced during early storage. Among ethylene biosynthetic genes, only FcACS3 showed enhanced expression under 1-MCP treatment throughout storage. The remaining genes generally exhibited contrasting expression trends in response to 1-MCP across the early and late stages of storage. 1-MCP application down-regulated the expression of FcETRs, FcEIN2, FcEIN4, FcERS1, FcCTRs, FcEBF1 and FcEILs to varying degrees during late storage. The expression of ethylene response factors (FcERFs) was differentially regulated by 1-MCP during storage. These data indicate that 1-MCP treatment can regulate the ripening and senescence of postharvest figs by mediating ethylene and PA metabolism.

关键词： 1,3-Oxathiolan-5-ones   Microwave-assisted synthesis   Green chemistry   Caenorhabditis elegans   Anthelmintic activity  

摘要：

• •
  A green, solvent- and catalyst-free synthesis of 1,3-oxathiolan-5-ones is reported.
• •
  Microwave-assisted cyclocondensation enables rapid access to diverse oxathiolanones.
• •
  Whole-organism bioactivity is demonstrated in a validated C. elegans model.
• •
  1,3-Oxathiolan-5-ones are identified as a new anthelmintic scaffold.