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The recent discovery of strongly correlated phases in twisted transition-metal dichalcogenides (TMDs) highlights the significant impact of twist-induced modifications on electronic structures. In this study, we employed angle-resolved photoemission spectroscopy with submicrometer spatial resolution (µ-ARPES) to investigate these modifications by comparing valence band structures of twisted (5.3°) and nontwisted (AB-stacked) bilayer regions within the same WSe2 device. Relative to the nontwisted region, the twisted area exhibits pronounced moiré bands and â¼90 meV renormalization at the Γ-valley, substantial momentum separation between different layers, and an absence of flat bands at the K-valley. We further simulated the effects of lattice relaxation, which can flatten the Γ-valley edge but not the K-valley edge. Our results provide a direct visualization of twist-induced modifications in the electronic structures of twisted TMDs and elucidate their valley-dependent responses to lattice relaxation.
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The purpose of this study was to explore the therapeutic effect of the oral administration of pseudo-ginsenoside RT4 (RT4) on ulcerative colitis (UC), and to determine the rate of absorption and distribution of RT4 in mice with UC. Balb/c mice were induced using dextran sulfate sodium salts (DSS) to establish the UC model, and 10, 20, or 40 mg/kg of RT4 was subsequently administered via gavage. The clinical symptoms, inflammatory response, intestinal barrier, content of total short-chain fatty acids (SCFAs), and gut microbiota were investigated. Caco-2 cells were induced to establish the epithelial barrier damage model using LPS, and an intervention was performed using 4, 8, and 16 µg/mL of RT4. The inflammatory factors, transient electrical resistance (TEER), and tight-junction protein expression were determined. Finally, pharmacokinetic and tissue distribution studies following the intragastric administration of RT4 in UC mice were performed. According to the results in mice, RT4 decreased the disease activity index (DAI) score, restored the colon length, reduced the levels of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1ß), and boosted the levels of immunosuppressive cytokine IL-10, increased the content of SCFAs, improved the colonic histopathology, maintained the ultrastructure of colonic mucosal epithelial cells, and corrected disturbances in the intestinal microbiota. Based on the results in caco-2 cells, RT4 reduced the levels of TNF-α, IL-6, and IL-1ß; protected integrity of monolayers; and increased tight-junction protein expression. Additionally, the main pharmacokinetic parameters (Cmax, Tmax, t1/2, Vd, CL, AUC) were obtained, the absolute bioavailability was calculated as 18.90% ± 2.70%, and the main distribution tissues were the small intestine and colon. In conclusion, RT4, with the features of slow elimination and directional distribution, could alleviate UC by inhibiting inflammatory factors, repairing the intestinal mucosal barrier, boosting the dominant intestinal microflora, and modulating the expression of SCFAs.
Assuntos
Colite Ulcerativa , Microbioma Gastrointestinal , Ginsenosídeos , Animais , Camundongos , Humanos , Distribuição Tecidual , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/tratamento farmacológico , Células CACO-2 , Interleucina-6 , Fator de Necrose Tumoral alfa , Citocinas , Interleucina-1beta , Camundongos Endogâmicos BALB CRESUMO
BACKGROUND: Yinhua Miyanling tablets (YMT), comprising 10 Chinese medicinal compounds, is a proprietary Chinese medicine used in the clinical treatment of urinary tract infections. Medicinal compounds, extracts, or certain monomeric components in YMT all show good effect on ulcerative colitis (UC). However, no evidence supporting YMT as a whole prescription for UC treatment is available. PURPOSE: To evaluate the anti-UC activity of YMT and elucidate the underlying mechanisms. The objective of the study was to provide evidence for the add-on development of YMT to treat UC. METHODS: First, YMT's protective effect on the intestinal barrier was evaluated using a lipopolysaccharide (LPS)-induced Caco-2 intestinal injury model. Second, the UC mouse model was established using dextran sodium sulfate (DSS) to determine YMT's influence on symptoms, inflammatory factors, intestinal barrier, and histopathological changes in the colon. Third, an integrated method combining metabolomics and network pharmacology was employed to screen core targets and key metabolic pathways with crucial roles in YMT's therapeutic effect on UC. Molecular docking was employed to identify the key targets with high affinity. Finally, western blotting was performed to validate the mechanism of YMT action against UC. RESULTS: YMT enhanced the transepithelial electrical resistance value and improved the expression of proteins of the tight junctions dose-dependently in LPS-induced Caco-2 cells. UC mice treated with YMT exhibited alleviated pathological lesions of the colon tissue in the in vivo pharmacodynamic experiments. The colonic lengths tended to be normal, and the levels of inflammatory factors (TNF-α, IL-6, and iNOS) along with those of the core enzymes (MPO, MDA, and SOD) improved. YMT effectively ameliorated DSS-induced colonic mucosal injury; pathological changes along with ultrastructure damage were significantly alleviated (evidenced by a relatively intact colon tissue, recovery of epithelial damage, repaired gland, reduced infiltration of inflammatory cells and epithelial cells arranged closely with dense microvilli). Seven key targets (IL-6, TNF-α, MPO, COX-2, HK2, TPH, and CYP1A2) and four key metabolic pathways (arachidonic acid metabolism, linoleate metabolism, glycolysis, and gluconeogenesis and tyrosine biosynthesis) were identified to play vital roles in the treatment on UC using YMT. CONCLUSIONS: YMT exerts beneficial therapeutic effects on UC by regulating multiple endogenous metabolites, targets, and metabolic pathways, suggestive of its potential novel application in UC treatment.
Assuntos
Colite Ulcerativa , Sulfato de Dextrana , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas , Metabolômica , Farmacologia em Rede , Animais , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/induzido quimicamente , Humanos , Células CACO-2 , Medicamentos de Ervas Chinesas/farmacologia , Masculino , Camundongos , Colo/efeitos dos fármacos , Colo/metabolismo , Colo/patologia , Comprimidos , Lipopolissacarídeos , Simulação de Acoplamento Molecular , Camundongos Endogâmicos C57BLRESUMO
BACKGROUND: (-)-Syringaresinol (SYR), a natural lignan with significant antioxidant and anti-inflammatory activities, possesses various pharmacological benefits including cardio-protective, antibacterial, anticancer, and anti-aging effects. It was shown that the effectiveness of (+)-syringaresinol diglucoside on the ulcerative colitis (UC) was attributed to the active metabolite (+)-syringaresinol (the enantiomor of SYR). However, the efficacy of SYR against UC remains unclear, and the associated molecular mechanism has not been revealed yet PURPOSE: This study aimed to assess the protective effect of SYR in UC and its underlying mechanism STUDY DESIGN AND METHODS: We examined SYR's protective impact on the intestinal epithelial barrier and its ability to inhibit inflammatory responses in both a lipopolysaccharide (LPS)-induced Caco-2 cell model and a dextran sodium sulfate (DSS)-induced UC mouse model. We also explored the potential signaling pathways regulated by SYR using transcriptome analysis and western blot assay RESULTS: In Caco-2 cells, SYR significantly increased trans-epithelial electrical resistance, reduced tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interferon-γ (IFN-γ), and cyclooxygenase-2 (COX-2) levels, and enhanced cellular tight junction protein expression and distribution. In mice with UC, oral treatment with SYR (10, 20, 40 mg·kg-1) dose-dependently increased body weight, colon length, and expression of tight junction proteins, decreased disease activity index score, spleen coefficient, cytokine serum levels, bacterial translocation, and intestinal damage, and also preserved the ultrastructure of colonic mucosal cells. Transcriptomics indicated that the anti-UC effect of SYR is mediated via the PI3K-Akt/MAPK/Wnt signaling pathway. CONCLUSION: In summary, SYR effectively mitigated the development of UC by enhancing the intestinal epithelial barrier function and attenuating the inflammatory response. The plant-derived product SYR might be a potentially effective therapeutical agent against UC.
Assuntos
Colite Ulcerativa , Colite , Furanos , Lignanas , Humanos , Animais , Camundongos , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/metabolismo , Células CACO-2 , Fosfatidilinositol 3-Quinases/metabolismo , Colo/patologia , Lignanas/farmacologia , Lignanas/uso terapêutico , Mucosa Intestinal/metabolismo , Modelos Animais de Doenças , Sulfato de Dextrana/efeitos adversos , Camundongos Endogâmicos C57BL , Colite/induzido quimicamenteRESUMO
Recently, there has been significant interest in topological nodal-line semimetals due to their linear energy dispersion with one-dimensional nodal lines or loops. These materials exhibit fascinating physical properties, such as drumhead surface states and 3D anisotropic nodal-line structures. Similar to Weyl semimetals, type-II nodal-line semimetals have two crossing bands that are both electron-like or hole-like along a certain direction. However, the direct observation of type-II nodal-line Fermions has been challenging due to the lack of suitable material platforms and the low density of states. Here we present experimental evidence for the coexistence of both type-I and type-II nodal-line Fermions in ZrSiSe, which was obtained through magneto-optical and angle-resolved photoemission spectroscopy (ARPES) measurements. Our density functional theory calculations predict that the type-II nodal-line structure can be developed in the Z-R line of the first Brillouin zone based on the lattice constants of the grown single crystal. Indeed, ARPES measurements reveal the type-II nodal-line band structure. The extracted type-II Landau level transitions from magneto-optical measurements exhibit good agreement with the calculated type-II energy dispersion model based on the band structure. Our experimental results demonstrate that ZrSiSe possesses two types of nodal-line Fermions, distinguishing it from other ZrSiX (X = S, Te) materials and positioning it as an ideal platform for investigating type-II nodal-line semimetals.
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Chronic obstructive pulmonary disease (COPD) is a prevalent respiratory disease. Aiming at assessing the effect of total saponins from American ginseng on COPD, both the chemical composition and anti-COPD activity of total saponins from wild-simulated American ginseng (TSW) and field-grown American ginseng (TSF) were investigated in this study. Firstly, a HPLC-ELSD chromatographic method was established to simultaneously determine the contents of 22 saponins in TSW and TSF. Secondly, CS-induced COPD mouse model was established to evaluate the activity of TSW and TSF. The results indicated that both TSW and TSF had the protective effect against COPD by alleviating oxidative stress and inflammatory response. TSW showed a stronger effect than TSF. Thirdly, an integrated approach involving metabolomics and network pharmacology was used to construct the "biomarker-reaction-enzyme-target" correlation network aiming at further exploring the observed effects. As the results, 15 biomarkers, 9 targets and 5 pathways were identified to play vital roles in the treatment of TSW and TSF on COPD. Fourthly, based on network pharmacology and the CS-stimulated A549 cell model, ginsenoside Rgl, Rc, oleanolic acid, notoginsenoside R1, Fe, silphioside B were certified to be the material basis for the stronger effect of TSW than TSF. Finally, the molecular docking were performed to visualize the binding modes. Our findings suggested that both TSW and TSF could effectively ameliorate the progression of COPD and might be used for the treatment of COPD.