RESUMEN
Magnetic kagome metals are a promising platform to develop unique quantum transport and optical phenomena caused by the interplay between topological electronic bands, strong correlations, and magnetic order. This interplay may result in exotic quasiparticles that describe the coupled electronic and spin excitations on the frustrated kagome lattice. Here, we observe novel elementary magnetic excitations within the ferromagnetic Mn kagome layers in TbMn6Sn6 using inelastic neutron scattering. We observe sharp, collective acoustic magnons and identify flat-band magnons that are localized to a hexagonal plaquette due to the special geometry of the kagome layer. Surprisingly, we observe another type of elementary magnetic excitation; a chiral magnetic quasiparticle that is also localized on a hexagonal plaquette. The short lifetime of localized flat-band and chiral quasiparticles suggest that they are hybrid excitations that decay into electronic states.
RESUMEN
Alzheimer's disease (AD) is an inflammatory associated disease, in which dysregulated kynurenine pathway (KP) plays a key role. Through KP, L-tryptophan is catabolized into neurotoxic and neuroprotective metabolites. The overactivation of indolamine 2,3-dioxygenase1 (IDO1), the first rate-limiting enzyme of KP, and the abnormal accumulation of KP metabolites have been noted in AD, and blocking IDO1 has been suggested as a therapeutic strategy. However, the expression patterns of KP enzymes in AD, and whether these enzymes are related to AD pathogenesis, have not been fully studied. Herein, we examined the expression patterns of inflammatory cytokines, neurotrophic factors and KP enzymes, and the activity of IDO1 and IDO1 effector pathway AhR (aryl hydrocarbon receptor) in AD mice. We studied the effects of IDO1 inhibitors on Aß-related neuroinflammation in rat primary neurons, mouse hippocampal neuronal cells, and APP/PS1 mice. The results further demonstrated the importance of IDO1-catalyzed KP in neuroinflammation in Alzheimer's disease.
Asunto(s)
Enfermedad de Alzheimer , Ratones , Ratas , Animales , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedades Neuroinflamatorias , Triptófano/metabolismo , Quinurenina/metabolismo , Neuronas/metabolismoRESUMEN
BACKGROUND: Alzheimer's disease (AD) is a common neurodegenerative disorder. Disulfidptosis is a newly discovered form of programmed cell death that holds promise as a therapeutic strategy for various disorders. However, the functional roles of disulfidptosis-related genes (DRGs) in AD remain unknown. METHODS: Microarray data and clinical information from patients with AD and healthy controls were downloaded from the Gene Expression Omnibus database. A thorough examination of DRG expression and immune characteristics in both groups was performed. Based on the identified DRGs, we performed an unsupervised clustering analysis to categorize the AD samples into various disulfidptosis-related molecular clusters. Weighted gene co-expression network analysis was performed to select hub genes specific to disulfidptosis-related AD clusters. The performances of various machine learning models were compared to determine the optimal predictive model. The predictive ability of the optimal model was assessed using nomogram analysis and five external datasets. RESULTS: Eight DRGs showed differential expression between the AD and control samples. Two different molecular clusters were identified. The immune cell infiltration analysis revealed distinct differences in the immune microenvironment of the two clusters. The support vector machine model showed the highest performance, and a panel of five signature genes was identified, which showed excellent performance on the external validation datasets. The nomogram analysis also showed high accuracy in predicting AD. CONCLUSION: We identified disulfidptosis-related molecular clusters in AD and established a novel risk model to assess the likelihood of developing AD. These findings revealed a complex association between disulfidptosis and AD, which may aid in identifying potential therapeutic targets for this debilitating disorder.
Asunto(s)
Enfermedad de Alzheimer , Humanos , Enfermedad de Alzheimer/genética , Apoptosis , Análisis por Conglomerados , Bases de Datos Factuales , Aprendizaje AutomáticoRESUMEN
Ferromagnetic (FM) order in a two-dimensional kagome layer is predicted to generate a topological Chern insulator without an applied magnetic field. The Chern gap is largest when spin moments point perpendicular to the kagome layer, enabling the capability to switch topological transport properties, such as the quantum anomalous Hall effect, by controlling the spin orientation. In TbMn6Sn6, the uniaxial magnetic anisotropy of the Tb3+ ion is effective at generating the Chern state within the FM Mn kagome layers while a spin-reorientation (SR) transition to easy-plane order above TSR = 310 K provides a mechanism for switching. Here, we use inelastic neutron scattering to provide key insights into the fundamental nature of the SR transition. The observation of two Tb excitations, which are split by the magnetic anisotropy energy, indicates an effective two-state orbital character for the Tb ion, with a uniaxial ground state and an isotropic excited state. The simultaneous observation of both modes below TSR confirms that orbital fluctuations are slow on magnetic and electronic time scales < ps and act as a spatially-random orbital alloy. A thermally-driven critical concentration of isotropic Tb ions triggers the SR transition.
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In Alzheimer's disease, the transporter P-glycoprotein is responsible for the clearance of amyloid-ß in the brain. Amyloid-ß correlates with the sphingomyelin metabolism, and sphingomyelin participates in the regulation of P-glycoprotein. The amyloid cascade hypothesis describes amyloid-ß as the central cause of Alzheimer's disease neuropathology. Better understanding of the change of P-glycoprotein and sphingomyelin along with amyloid-ß and their potential association in the pathological process of Alzheimer's disease is critical. Herein, we found that the expression of P-glycoprotein in APP/PS1 mice tended to increase with age and was significantly higher at 9 and 12 months of age than that in wild-type mice at comparable age. The functionality of P-glycoprotein of APP/PS1 mice did not change with age but was significantly lower than that of wild-type mice at 12 months of age. Decreased sphingomyelin levels, increased ceramide levels, and the increased expression and activity of neutral sphingomyelinase 1 were observed in APP/PS1 mice at 9 and 12 months of age compared with the levels in wild-type mice. Similar results were observed in the Alzheimer's disease mouse model induced by intracerebroventricular injection of amyloid-ß1-42 and human cerebral microvascular endothelial cells treated with amyloid-ß1-42. In human cerebral microvascular endothelial cells, neutral sphingomyelinase 1 inhibitor interfered with the changes of sphingomyelin metabolism and P-glycoprotein expression and functionality caused by amyloid-ß1-42 treatment. Neutral sphingomyelinase 1 regulated the expression and functionality of P-glycoprotein and the levels of sphingomyelin and ceramide. Together, these findings indicate that neutral sphingomyelinase 1 regulates the expression and function of P-glycoprotein via the sphingomyelin/ceramide pathway. These studies may serve as new pursuits for the development of anti-Alzheimer's disease drugs.
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Background: Although blood-activating Chinese medicine (BACM) has been reported as adjuvant therapy for intracranial hemorrhage (ICH) in China, high-quality evidence is still lacking. Our study aimed to collect the latest high-quality randomized controlled trials (RCTs) and to evaluate the efficacy and safety of BACM for ICH. Methods: RCTs published between January 2015 and March 2022 were searched in databases, including China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database (VIP), Sino-Med, Wanfang, PubMed, Web of Science, Cochrane Library, and Embase without language restrictions. Eligible RCTs were included and both primary (clinical efficacy evidenced by decreased neurological deficit scores) and secondary outcomes (increased Barthel index, decreased NIHSS, hematoma volume, the volume of cerebral edema, the incidence of side effects, and mortality) were analyzed. The quality of included RCTs was assessed using the Cochrane risk of bias tool. In the meta-analysis, the pooled results were analyzed using Review Manager 5.3 and STATA14.0. Finally, The GRADEpro GDT software (Guideline Development Tool) was used to summarize the results. Sensitivity and subgroup analyses were conducted based on the follow-up time. Results: Fifteen RCTs, involving 1,579 participants, were included for analysis in our study. The pooled outcomes indicated that BACM combined with western medicine treatment (WMT) was superior to WMT alone for patients with ICH, demonstrated by the improvements in efficacy (RR = 1.22 (95% CI, [1.13 to 1.32], p < 0.001), neurological functions (MDNIHSS = -2.75, 95% CI [-3.74 to -1.76], p < 0.001), and activities of daily living (MDBarthel index = 5.95, 95% CI [3.92 to 7.98], p < 0.001), as well as decreased cerebral hematoma, cerebral edema (MD cerebral hematoma = -2.94, 95% CI [-3.50 to -2.37, p < 0.001 and MDcerebral edema = -2.66, 95% CI [-2.95 to -2.37], p < 0.001), side effects and mortality (RR = 0.84 (95% CI [0.60 to 1.19], p = 0.330 and RR = 0.51 (95% CI, [0.16 to 1.65], p = 0.260). In addition, Conioselinum anthriscoides "Chuanxiong" [Apiaceae], Camellia reticulata Lindl. [Theaceae], and Bupleurum sibiricum var. jeholense (Nakai) C.D.Chu [Apiaceae]) were the most frequently used herbs in the treatment of ICH. Recently, there was a trend toward the extensive use of another two herbs, including Rheum palmatum L. [Polygonaceae], Astragalus mongholicus Bunge [Fabaceae]) for ICH. Conclusion: BACM combined with WMT seems to be superior to WMT alone for patients with ICH. Further high-quality RCTs are warranted to confirm the efficacy and safety of BACM.
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A new approach to treat infections of highly pathogenic influenza virus is to inhibit excessive innate immune response. JiuWei QiangHuo decoction has been used for centuries for the treatment of pulmonary disorders in China. In this study, we evaluated the anti-inflammatory activities of the modified JiuWei QiangHuo (MJWQH) decoction in the treatment of influenza A (H1N1) virus-induced severe pneumonia in mice. The results showed that MJWQH significantly increased the survival rate of H1N1-infected mice and suppressed the production of TNF-α, IL-1, IL-6, MCP-1, RANTES, and IFN-α on day 4 after infection. Moreover, oral administration of MJWQH efficiently inhibited virus replication and alleviated the severity of lung injuries. The results also showed that MJWQH may have potential therapeutic effect on severe lung injury induced by H1N1 virus by regulating the NF-κB pathway. Our study suggested that MJWQH might be an alternative therapy for the treatment of viral pneumonia.