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The Hippo signaling pathway functions through Yorkie to control tissue growth and homeostasis. How this pathway regulates non-developmental processes remains largely unexplored. Here, we report an essential role for Hippo signaling in innate immunity whereby Yorkie directly regulates the transcription of the Drosophila IκB homolog, Cactus, in Toll receptor-mediated antimicrobial response. Loss of Hippo pathway tumor suppressors or activation of Yorkie in fat bodies, the Drosophila immune organ, leads to elevated cactus mRNA levels, decreased expression of antimicrobial peptides, and vulnerability to infection by Gram-positive bacteria. Furthermore, Gram-positive bacteria acutely activate Hippo-Yorkie signaling in fat bodies via the Toll-Myd88-Pelle cascade through Pelle-mediated phosphorylation and degradation of the Cka subunit of the Hippo-inhibitory STRIPAK PP2A complex. Our studies elucidate a Toll-mediated Hippo signaling pathway in antimicrobial response, highlight the importance of regulating IκB/Cactus transcription in innate immunity, and identify Gram-positive bacteria as extracellular stimuli of Hippo signaling under physiological settings.
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Drosophila melanogaster/inmunología , Inmunidad Innata , Transducción de Señal , Animales , Proteínas de Unión al ADN/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/crecimiento & desarrollo , Drosophila melanogaster/metabolismo , Drosophila melanogaster/microbiología , Escherichia coli/fisiología , Cuerpo Adiposo/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Larva/metabolismo , Masculino , Pectobacterium carotovorum/fisiología , Fosfoproteínas/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Staphylococcus aureus/fisiología , Receptores Toll-Like/metabolismoRESUMEN
Although Merlin/NF2 was discovered two decades ago as a tumor suppressor underlying Neurofibromatosis type II, its precise molecular mechanism remains poorly understood. Recent studies in Drosophila revealed a potential link between Merlin and the Hippo pathway by placing Merlin genetically upstream of the kinase Hpo/Mst. In contrast to the commonly depicted linear model of Merlin functioning through Hpo/Mst, here we show that in both Drosophila and mammals, Merlin promotes downstream Hippo signaling without activating the intrinsic kinase activity of Hpo/Mst. Instead, Merlin directly binds and recruits the effector kinase Wts/Lats to the plasma membrane. Membrane recruitment, in turn, promotes Wts phosphorylation by the Hpo-Sav kinase complex. We further show that disruption of the actin cytoskeleton promotes Merlin-Wts interactions, which implicates Merlin in actin-mediated regulation of Hippo signaling. Our findings elucidate an important molecular function of Merlin and highlight the plasma membrane as a critical subcellular compartment for Hippo signal transduction.
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Membrana Celular/metabolismo , Drosophila melanogaster/metabolismo , Neurofibromina 2/metabolismo , Transducción de Señal , Secuencia de Aminoácidos , Animales , Evolución Biológica , Citoesqueleto/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Ratones , Datos de Secuencia Molecular , Proteínas Serina-Treonina Quinasas/metabolismo , Alineación de SecuenciaRESUMEN
Herein, we report a versatile reaction platform for tracelessly cleavable cysteine-selective peptide/protein modification. This platform offers highly tunable and predictable conjugation and cleavage by rationally estimating the electron effect on the nucleophilic halopyridiniums. Cleavable peptide stapling, antibody conjugation, enzyme masking/de-masking, and proteome labeling were achieved based on this facile pyridinium-thiol-exchange protocol.
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Péptidos , Proteoma , Cisteína/metabolismoRESUMEN
Human epidermal growth factor receptor-2 (HER2), programmed death-ligand 1 (PD-L1), and microsatellite (MS) status are well-established biomarkers in gastroesophageal adenocarcinomas (GEAs). However, it is unclear how the combination of these biomarkers is associated with clinicopathological factors and prognosis. This retrospective study included baseline metastatic GEA patients who were tested for all three biomarkers (HER2, PD-L1, and MS status) at the MD Anderson Cancer Center between 2012 and 2022. Stratification was performed according to the combination of biomarker profiles: triple negative (TN), single positive (SP), and multiple positive (MP). Comparative analyses of clinicopathological factors and survival using combinations of biomarkers were performed. Among the 698 GEA patients analyzed, 251 (36.0%) were classified as TN, 334 (47.9%) as SP, and 113 (16.1%) as MP. The MP group showed a significant association with tumors located in the esophagus (p < .001), well to moderate differentiation (p < .001), and the absence of signet ring cells (p < .001). In the survival analysis, MP group had a significantly longer overall survival (OS) compared to the other groups (MP vs. TN, p < .001 and MP vs. SP, p < .001). Multivariate Cox regression analysis revealed that MP serves as an independent positive prognostic indicator for OS (hazard ratio = 0.63, p < .01). Our findings indicate that MP biomarkers are associated with a favorable prognosis in metastatic GEA. These results are reflective of clinical practice and offer valuable insights into how therapeutics and future biomarkers could influence therapy/prognosis.
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BACKGROUND: Lung adenocarcinoma (LUAD), the most common and lethal subtype of lung cancer, continues to be a major health concern worldwide. Despite advances in targeted and immune therapies, only a minority of patients derive substantial benefits. As a result, the urgent need for novel therapeutic strategies to improve lung cancer treatment outcomes remains undiminished. METHODS: In our study, we employed the TIMER database to scrutinize TNFSF11 expression across various cancer types. We further examined the differential expression of TNFSF11 in normal and tumor tissues utilizing the TCGA-LUAD dataset and tissue microarray, and probed the associations between TNFSF11 expression and clinicopathological parameters within the TCGA-LUAD dataset. We used the GSE31210 dataset for external validation. To identify genes strongly linked to TNFSF11, we engaged LinkedOmics and conducted a KEGG pathway enrichment analysis using the WEB-based Gene SeT AnaLysis Toolkit. Moreover, we investigated the function of TNFSF11 through gene knockdown or overexpression approaches and explore its function in tumor cells. The therapeutic impact of ferroptosis inducers in tumors overexpressing TNFSF11 were also investigated through in vivo and in vitro experiments. Through these extensive analyses, we shed light on the potential role of TNFSF11 in lung adenocarcinoma, underscoring potential therapeutic targets for this malignancy. RESULTS: This research uncovers the overexpression of TNFSF11 in LUAD patients and its inverse correlation with peroxisome-related enzymes. By utilizing gene knockdown or overexpression assays, we found that TNFSF11 was negatively associated with GPX4. Furthermore, cells with TNFSF11 overexpression were relatively more sensitive to the ferroptosis inducers. CONCLUSIONS: Our research has provided valuable insights into the role of TNFSF11, revealing its negative regulation of GPX4, which could be influential in crafting therapeutic strategies. These findings set the stage for further exploration into the mechanisms underpinning the relationship between TNFSF11 and GPX4, potentially opening up new avenues for precision medicine in the treatment of LUAD.
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Adenocarcinoma del Pulmón , Ferroptosis , Neoplasias Pulmonares , Humanos , Adenocarcinoma del Pulmón/genética , Bioensayo , Bases de Datos Factuales , Ferroptosis/genética , Neoplasias Pulmonares/genética , Ligando RANKRESUMEN
Hyperthermia stimulates ventilation in humans. This hyperthermia-induced hyperventilation may be mediated by the activation of peripheral chemoreceptors implicated in the regulation of respiration in reaction to various chemical stimuli, including reductions in arterial pH. Here, we investigated the hypothesis that during passive heating at rest, the increases in arterial pH achieved with sodium bicarbonate ingestion, which could attenuate peripheral chemoreceptors activity, mitigate hyperthermia-induced hyperventilation. We also assessed that the effect of sodium bicarbonate ingestion on cerebral blood flow responses, which are associated with hyperthermia-induced hyperventilation. Twelve healthy men ingested a sodium bicarbonate (0.3 g/kg body weight) or sodium chloride (0.208 g/kg). One hundred minutes after the ingestion, the participants were passively heated using hot-water immersion (42°C) combined with a water-perfused suit. Increases in esophageal temperature (an index of core temperature) and minute ventilation (VE) during the heating were similar in the two trials. Moreover, when VE is expressed as a function of esophageal temperature, there were no between-trial differences in the core temperature threshold for hyperventilation (37.9 ± 0.3 vs. 38.0 ± 0.4°C, P = 0.338), and sensitivity of hyperthermia-induced hyperventilation as assessed by the slope of the core temperature-VE relation (13.7 ± 14.9 vs. 15.8 ± 15.6 L/min/°C, P = 0.748). Furthermore, middle cerebral artery mean blood velocity (an index of cerebral blood flow) decreased similarly with heating duration in both trials. These results suggest that sodium bicarbonate ingestion does not mitigate hyperthermia-induced hyperventilation and the reductions in cerebral blood flow index in resting heated humans.
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Systemic autoimmune diseases (SADs) are a growing spectrum of autoimmune disorders that commonly affect multiple organs. The role of Epstein-Barr virus (EBV) infection or reactivation as a trigger for the initiation and progression of SADs has been established, while the relationship between EBV envelope glycoproteins and SADs remains unclear. Here, we assessed the levels of IgG, IgA, and IgM against EBV glycoproteins (including gp350, gp42, gHgL, and gB) in serum samples obtained from patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), and found that RA and SLE patients exhibited a statistically significant increase in the levels of 8 and 11 glycoprotein antibodies, respectively, compared to healthy controls (p < 0.05). The LASSO model identified four factors as significant diagnostic markers for RA: gp350 IgG, gp350 IgA, gHgL IgM, and gp42 IgA; whereas for SLE it included gp350 IgG, gp350 IgA, gHgL IgA, and gp42 IgM. Combining these selected biomarkers yielded an area under the curve (AUC) of 0.749 for RA and 0.843 for SLE. We subsequently quantified the levels of autoantibodies associated with SADs in mouse sera following immunization with gp350. Remarkably, none of the tested autoantibody levels exhibited statistically significant alterations. Elevation of glycoprotein antibody concentration suggests that Epstein-Barr virus reactivation and replication occurred in SADs patients, potentially serving as a promising biomarker for diagnosing SADs. Moreover, the absence of cross-reactivity between gp350 antibodies and SADs-associated autoantigens indicates the safety profile of a vaccine based on gp350 antigen.
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Artritis Reumatoide , Enfermedades Autoinmunes , Infecciones por Virus de Epstein-Barr , Lupus Eritematoso Sistémico , Humanos , Animales , Ratones , Infecciones por Virus de Epstein-Barr/complicaciones , Herpesvirus Humano 4 , Anticuerpos Antivirales , Artritis Reumatoide/complicaciones , Glicoproteínas , Enfermedades Autoinmunes/complicaciones , Inmunoglobulina G , Inmunoglobulina A , Inmunoglobulina MRESUMEN
The objective was to assess if post-exercise ingestion of carbonated water in a hot environment ameliorates hypotension, enhances cerebral blood flow and heat loss responses, and positively modulates perceptions and mood states. Twelve healthy, habitually active young adults (five women) performed 60 min of cycling at 45% peak oxygen uptake in a hot climate (35°C). Subsequently, participants consumed 4°C carbonated or non-carbonated (control) water (150 and 100 mL for males and females regardless of drink type) at 20 and 40 min into post-exercise periods. Mean arterial pressure decreased post-exercise at 20 min only (P = 0.032) compared to the pre-exercise baseline. Both beverages transiently (â¼1 min) increased mean arterial pressure and middle cerebral artery mean blood velocity (cerebral blood flow index) regardless of post-exercise periods (all P ≤ 0.015). Notably, carbonated water ingestion led to greater increases in mean arterial pressure (2.3 ± 2.8 mmHg vs. 6.6 ± 4.4 mmHg, P < 0.001) and middle cerebral artery mean blood velocity (1.6 ± 2.5 cm/s vs. 3.8 ± 4.1 cm/s, P = 0.046) at 20 min post-exercise period compared to non-carbonated water ingestion. Both beverages increased mouth exhilaration and reduced sleepiness regardless of post-exercise periods, but these responses were more pronounced with carbonated water ingestion at 40 min post-exercise (mouth exhilaration: 3.1 ± 1.4 vs. 4.7 ± 1.7, P = 0.001; sleepiness: -0.7 ± 0.91 vs. -1.9 ± 1.6, P = 0.014). Heat loss responses and other perceptions were similar between the two conditions throughout (all P ≥ 0.054). We show that carbonated water ingestion temporarily ameliorates hypotension and increases the cerebral blood flow index during the early post-exercise phase in a hot environment, whereas it enhances mouth exhilaration and reduces sleepiness during the late post-exercise phase.
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OBJECTIVE: The pathogenic mechanisms of syphilis and the host defense mechanisms against syphilis remain poorly understood. Exploration of the susceptibility factors of syphilis may provide crucial clues for unraveling its underlying mechanisms. METHODS: A two-sample Mendelian Randomization framework was utilized, and the inverse-variance weighted method was used as the main analysis. All data was sourced from Genome-wide association studies datasets from 2015 to 2022 in Europe, and all participants were of European descent. Only summary-level statistics were used. Sensitivity analyses were conducted to evaluate the heterogeneity and pleiotropy of the datasets. RESULTS: Our study established 18 exposure factors (12 risk factors and 6 protective factors) for syphilis susceptibility. Twelve factors encompassing body mass index, waist circumference, darker natural skin, cooked vegetable intake, processed meat intake, diabetes mellitus, glucose regulation disorders, gout, autoimmune diseases, rheumatoid arthritis, diverticulitis, and longer menstrual cycles were found to increase susceptibility to syphilis. In contrast, 6 factors including easier skin tanning, blonde natural hair color, irritability, higher neuroticism scores, extended sleep duration, and delayed age at first sexual intercourse were connected to a reduced risk of syphilis infection (all P < 0.05). CONCLUSIONS: This study identified 18 influencing factors of syphilis susceptibility. These findings offered novel insights for further probing into the underlying pathogenic mechanisms of syphilis and underscored the importance of multifaceted prevention strategies against syphilis.
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Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Análisis de la Aleatorización Mendeliana , Sífilis , Humanos , Sífilis/epidemiología , Factores de Riesgo , Europa (Continente)/epidemiología , Femenino , MasculinoRESUMEN
ABSTRACT: This study seeks to identify the anticoagulant efficacy of rivaroxaban treatment on thrombi detected using echocardiography of the left atrial appendage in 275 patients with persistent atrial fibrillation. During follow-up after 9-24 weeks of rivaroxaban treatment, patients were divided into "effective group" (n = 143) and "ineffective group" (n = 132) according to the thrombolytic effect of the drug. Left atrial diameter (LAD), left atrial ejection fraction (LAEF), left ventricular ejection fraction (LVEF), mean diameter of left atrial appendage (LAAD mean ), angle between left atrial appendage and left atrium (LAA-A), velocity of blood flow in left atrial appendage (LAA-v), and thrombus size were compared before and after drug administration. Following treatment, LAEF, LVEF, and LAA-v values were greater and LAD and LAAD mean values were lower in the effective ( P < 0.05). Logistic regression analysis showed significant correlations of LAD, LAEF, LVEF, LAA-A, and LAA-v with anticoagulant efficacy ( P < 0.05). The efficacy of rivaroxaban in treatment of left atrial auricular thrombosis in patients with persistent AF was correlated with LAD, LAEF, LVEF, LAA-A, and LAA-v. Multivariate logistic regression analysis further revealed LAEF [odds ratio (OR) 1.7, 95% confidence interval (CI), 0.45-16.9, P = 0.008], 3D-EF (OR 6.4, 95% CI, 1.06-16.9, P = 0.039) and left ventricular global longitudinal strain (OR 18.0, 95% CI, 1.38-35.68, P = 0.028) as factors related to left atrial appendage thrombus. Echocardiography with global longitudinal strain assessment could be effectively utilized to evaluate the functional parameters of LAA and thus aid in predicting the safety of rivaroxaban as an anticoagulation agent.
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Apéndice Atrial , Fibrilación Atrial , Ecocardiografía Tridimensional , Inhibidores del Factor Xa , Rivaroxabán , Humanos , Fibrilación Atrial/tratamiento farmacológico , Fibrilación Atrial/fisiopatología , Fibrilación Atrial/diagnóstico por imagen , Fibrilación Atrial/diagnóstico , Femenino , Masculino , Rivaroxabán/uso terapéutico , Rivaroxabán/administración & dosificación , Anciano , Persona de Mediana Edad , Resultado del Tratamiento , Apéndice Atrial/diagnóstico por imagen , Apéndice Atrial/fisiopatología , Apéndice Atrial/efectos de los fármacos , Inhibidores del Factor Xa/efectos adversos , Inhibidores del Factor Xa/uso terapéutico , Trombosis/diagnóstico por imagen , Trombosis/tratamiento farmacológico , Trombosis/fisiopatología , Valor Predictivo de las Pruebas , Función del Atrio Izquierdo/efectos de los fármacos , Terapia Trombolítica , Función Ventricular Izquierda/efectos de los fármacos , Factores de TiempoRESUMEN
BACKGROUND: Coronavirus disease 2019 (COVID-19) is an evolving global pandemic, and nanobodies, as well as other single-domain antibodies (sdAbs), have been recognized as a potential diagnostic and therapeutic tool for infectious diseases. High-throughput screening techniques such as phage display have been developed as an alternative to in vivo immunization for the discovery of antibody-like target-specific binders. METHODS: We designed and constructed a highly diverse synthetic phage library sdAb-U (single-domain Antibody - Universal library ) based on a human framework. The SARS-CoV-2 receptor-binding domain (RBD) was expressed and purified. The universal library sdAb-U was panned against the RBD protein target for two rounds, followed by monoclonal phage ELISA (enzyme-linked immunosorbent assay) to identify RBD-specific binders (the first stage). High-affinity binders were sequenced and the obtained CDR1 and CDR2 sequences were combined with fully randomized CDR3 to construct a targeted (focused) phage library sdAb-RBD, for subsequent second-stage phage panning (also two rounds) and screening. Then, sequences with high single-to-background ratios in phage ELISA were selected for expression. The binding affinities of sdAbs to RBD were measured by an ELISA-based method. In addition, we conducted competition ELISA (using ACE2 ectodomain S19-D615) and SARS-CoV-2 pseudovirus neutralization assays for the high-affinity RBD-binding sdAb39. RESULTS: Significant enrichments were observed in both the first-stage (universal library) and the second-stage (focused library) phage panning. Five RBD-specific binders were identified in the first stage with high ELISA signal-to-background ratios. In the second stage, we observed a much higher possibility of finding RBD-specific clones in phage ELISA. Among 45 selected RBD-positive sequences, we found eight sdAbs can be well expressed, and five of them show high-affinity to RBD (EC50 < 100nM). We finally found that sdAb39 (EC50 ~ 4nM) can compete with ACE2 for binding to RBD. CONCLUSION: Overall, this two-stage strategy of synthetic phage display libraries enables rapid selection of SARS-CoV-2 RBD sdAb with potential therapeutic activity, and this two-stage strategy can potentially be used for rapid discovery of sdAbs against other targets.
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Bacteriófagos , COVID-19 , Anticuerpos de Dominio Único , Humanos , SARS-CoV-2/genética , Anticuerpos de Dominio Único/genética , Anticuerpos de Dominio Único/química , Enzima Convertidora de Angiotensina 2 , COVID-19/diagnóstico , Anticuerpos Antivirales , Anticuerpos NeutralizantesRESUMEN
To identify superalkali-alkaline earthide ion pairs, it's theoretically shown that, as a novel class of excess electron superalkali compounds, both chair and boat forms of (AM-HMHC)-AM' (AM = Li, Na, and K; AM' = Be, Mg, and Ca; HMHC = 1,4,7,10,13,16-hexamethyl-1,4,7,10,13,16-hexaazacyclooctadecane) are good candidates. An attractive superalkali-alkaline earthide ion pair in δ+(AM-HMHC)-AM'δ- is firstly exhibited, which possesses alkaline-earthide characteristics and nonlinear optical response superior to similar M+(calix[4]pyrrole)M'- (M = Li, Na, and K; M' = Be, Mg, and Ca) with high stability. The electronic and vibrational second order hyperpolarizabilities and the frequency-dependent first hyperpolarizabilities of δ+(AM-HMHC)-AM'δ- are presented. For each pair of (AM-HMHC)-AM', the boat conformation is preferred to its chair one in the case of Hyper-Rayleigh scattering response (ßHRS). These alkaline earthides suggest prominently high ßHRS up to 2.59 × 104 a.u. (boat forms of δ+(Na-HMHC)-Caδ-). We expect that this work will inspire the preparation and characterization of these new alkaline earthides as high-performance NLO materials.
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FK228 is a potent natural pan HDAC inhibitor approved by the FDA for the treatment of cutaneous T-cell lymphoma as well as peripheral T-cell lymphoma. It is generally believed that the mechanism of FK228 acting on HDACs is by reducing its disulfide bond after entering the cell, and the dithiol group may chelate with Zn2+ and form a weak reversible covalent bond with cysteine in the catalytic pocket of HDACs, therefore inhibiting the activity of HDACs. However, due to the weak stability of the disulfide bond in FK228, it has been difficult to obtain direct evidence for the above conjecture. Thus, improving the stability of the FK228 disulfide bond will help to explore the exact mechanism of FK228. In this study, based on the stability and target-induced covalent properties of the Cysteine-Penicillamine (Cys-Pen) disulfide bond reported previously, the Pen was introduced into the modification of FK228. Specifically, the d-Cys in FK228 was replaced by d-Pen, the total synthetic pathway was optimized, and the novel synthetic FK228 analogue (FK-P) stability was verified. FK-P can also be used as a new drug molecule in the future to participate in the research of related biological mechanisms or the treatment of diseases.
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Cisteína , Depsipéptidos , Depsipéptidos/química , Inhibidores de Histona Desacetilasas/farmacología , DisulfurosRESUMEN
Extracellular regulated protein kinases 1/2 (ERK1/2) are key members of multiple signaling pathways, including the ErbB axis. Ectopic ERK1/2 activation contributes to various types of cancer, especially drug resistance to inhibitors of RTK, RAF and MEK, and specific ERK1/2 inhibitors are scarce. In this study, we identified a potential novel covalent ERK inhibitor, Laxiflorin B, which is a herbal compound with anticancer activity. However, Laxiflorin B is present at low levels in herbs; therefore, we adopted a semi-synthetic process for the efficient production of Laxiflorin B to improve the yield. Laxiflorin B induced mitochondria-mediated apoptosis via BAD activation in non-small-cell lung cancer (NSCLC) cells, especially in EGFR mutant subtypes. Transcriptomic analysis suggested that Laxiflorin B inhibits amphiregulin (AREG) and epiregulin (EREG) expression through ERK inhibition, and suppressed the activation of their receptors, ErbBs, via a positive feedback loop. Moreover, mass spectrometry analysis combined with computer simulation revealed that Laxiflorin B binds covalently to Cys-183 in the ATP-binding pocket of ERK1 via the D-ring, and Cys-178 of ERK1 through non-inhibitory binding of the A-ring. In a NSCLC tumor xenograft model in nude mice, Laxiflorin B also exhibited strong tumor suppressive effects with low toxicity and AREG and EREG were identified as biomarkers of Laxiflorin B efficacy. Finally, Laxiflorin B-4, a C-6 analog of Laxiflorin B, exhibited higher binding affinity for ERK1/2 and stronger tumor suppression. These findings provide a new approach to tumor inhibition using natural anticancer compounds.
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Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Ratones , Animales , Humanos , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Receptores ErbB , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Sistema de Señalización de MAP Quinasas , Ratones Desnudos , Simulación por Computador , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Mutación , Línea Celular TumoralRESUMEN
Ischemic stroke is a major cause of disability and death worldwide, and its management requires urgent attention. Previous studies have shown that vagus nerve stimulation (VNS) exerts neuroprotection in ischemic stroke by inhibiting neuroinflammation and apoptosis. In this study, we evaluated the timing for VNS intervention in ischemic stroke, and the underlying mechanisms of VNS-induced neuroprotection. Mice were subjected to transient middle cerebral artery occlusion (tMCAO) for 60 min. The left vagus nerve at cervical level was exposed and attached to an electrode connected to a low-frequency electrical stimulator. Vagus nerve stimulation (VNS) was given for 60 min before, during and after tMCAO (Pre-VNS, Dur-VNS, Post-VNS). Neurological function was assessed 24 h after reperfusion. We found that all the three VNS significantly protected against the tMCAO-induced injury evidenced by improved neurological function and reduced infarct volume. Moreover, the Pre-VNS was the most effective against the ischemic injury. We found that tMCAO activated microglia in the ischemic core and penumbra regions of the brain, followed by the NLRP3 inflammasome activation-induced neuroinflammation, which finally triggered neuronal death. VNS treatment preserved α7nAChR expression in the penumbra regions, inhibited NLRP3 inflammasome activation and ensuing neuroinflammation, rescuing cerebral neurons. The role of α7nAChR in microglial NLRP3 inflammasome activation in ischemic stroke was further validated using genetic manipulations, including Chrna7 knockout mice and microglial Chrna7 overexpression mice, as well as pharmacological interventions using the α7nAChR inhibitor methyllycaconitine and agonist PNU-282987. Collectively, this study demonstrates the potential of VNS as a safe and effective strategy to treat ischemic stroke, and presents a new approach targeting microglial NLRP3 inflammasome, which might be therapeutic for other inflammation-related diseases.
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Infarto de la Arteria Cerebral Media , Inflamasomas , Accidente Cerebrovascular Isquémico , Ratones Endogámicos C57BL , Microglía , Proteína con Dominio Pirina 3 de la Familia NLR , Estimulación del Nervio Vago , Receptor Nicotínico de Acetilcolina alfa 7 , Animales , Receptor Nicotínico de Acetilcolina alfa 7/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Estimulación del Nervio Vago/métodos , Accidente Cerebrovascular Isquémico/metabolismo , Microglía/metabolismo , Ratones , Inflamasomas/metabolismo , Masculino , Infarto de la Arteria Cerebral Media/terapia , Neuroprotección , Ratones NoqueadosRESUMEN
CENP-A is a centromere-specific histone 3 variant essential for centromere specification. CENP-A partially replaces canonical histone H3 at the centromeres. How the particular CENP-A/H3 ratio at centromeres is precisely maintained is unknown. It also remains unclear how CENP-A is excluded from non-centromeric chromatin. Here, we identify Ccp1, an uncharacterized NAP family protein in fission yeast that antagonizes CENP-A loading at both centromeric and non-centromeric regions. Like the CENP-A loading factor HJURP, Ccp1 interacts with CENP-A and is recruited to centromeres at the end of mitosis in a Mis16-dependent manner. These data indicate that factors with opposing CENP-A loading activities are recruited to centromeres. Furthermore, Ccp1 also cooperates with H2A.Z to evict CENP-A assembled in euchromatin. Structural analyses indicate that Ccp1 forms a homodimer that is required for its anti-CENP-A loading activity. Our study establishes mechanisms for maintenance of CENP-A homeostasis at centromeres and the prevention of ectopic assembly of centromeres.
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Carboxipeptidasas/genética , Proteínas Portadoras/genética , Proteínas Cromosómicas no Histona/genética , Eucromatina/química , Regulación Fúngica de la Expresión Génica , Proteínas de Schizosaccharomyces pombe/genética , Schizosaccharomyces/genética , Sitios de Unión , Carboxipeptidasas/química , Carboxipeptidasas/metabolismo , Proteínas Portadoras/química , Proteínas Portadoras/metabolismo , Centrómero/química , Centrómero/metabolismo , Centrómero/ultraestructura , Ensamble y Desensamble de Cromatina , Proteínas Cromosómicas no Histona/química , Proteínas Cromosómicas no Histona/metabolismo , Eucromatina/metabolismo , Eucromatina/ultraestructura , Histonas/química , Histonas/genética , Histonas/metabolismo , Mitosis , Unión Proteica , Conformación Proteica en Hélice alfa , Conformación Proteica en Lámina beta , Dominios y Motivos de Interacción de Proteínas , Multimerización de Proteína , Schizosaccharomyces/metabolismo , Schizosaccharomyces/ultraestructura , Proteínas de Schizosaccharomyces pombe/química , Proteínas de Schizosaccharomyces pombe/metabolismo , Transducción de SeñalRESUMEN
The taxonomic relationship between Streptomyces violarus and Streptomyces violaceus was reevaluated using a polyphasic taxonomic approach in this work. Phylogenetic analysis based on 16S rRNA gene sequences indicated that Streptomyces violarus JCM 4534 T was closely related to Streptomyces arenae ISP 5293 T. However, phylogenetic analysis based on five house-keeping gene (atpD, gyrB, recA, rpoB and trpB) showed that the evolutionary neighbor of Streptomyces violarus JCM 4534 T was Streptomyces violaceus CGMCC 4.1456 T, suggesting that there was a close genetic relationship between these two strains. The average nucleotide identity and digital DNA-DNA hybridization values between them were 97.0 and 72.9%, respectively, greater than the 96.7 and 70% cut-off points recommended for delineating a Streptomyces species. This result indicated that they belonged to the same genomic species which was also verified by a comprehensive comparison of phenotypic and chemotaxonomic characteristics between Streptomyces violarus JCM 4534 T and Streptomyces violaceus CGMCC 4.1456 T. According to all these data and the rule of priority in nomenclature, it is proposed the Streptomyces violarus (Artamonova and Krassilnikov 1960) Pridham 1970 is a later heterotypic synonym of Streptomyces violaceus (Rossi Doria 1891) Waksman 1953. In addition, based on dDDH, Streptomyces violaceus and Streptomyces violarus are simultaneously designated as two different subspecies, i.e., Streptomyces violaceus subsp. violaceus and Streptomyces violaceus subsp. violarus.
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ADN Bacteriano , Filogenia , ARN Ribosómico 16S , Streptomyces , Streptomyces/genética , Streptomyces/clasificación , ARN Ribosómico 16S/genética , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Análisis de Secuencia de ADN , Hibridación de Ácido Nucleico , Proteínas Bacterianas/genéticaRESUMEN
PURPOSE: We evaluated (1) whether participating in middle- and long-distance running races augments muscle soreness, oxygen cost, respiration, and exercise exertion during subsequent running, and (2) if post-race menthol application alleviates these responses in long-distance runners. METHODS: Eleven long-distance runners completed a 1500-m race on day 1 and a 3000-m race on day 2. On day 3 (post-race day), either a 4% menthol solution (Post-race menthol) or a placebo solution (Post-race placebo) serving as a vehicle control, was applied to their lower leg skin, and their perceptual and physiological responses were evaluated. The identical assessment with the placebo solution was also conducted without race participation (No-race placebo). RESULTS: The integrated muscle soreness index increased in the Post-race placebo compared to the No-race placebo (P < 0.001), but this response was absent in the Post-race menthol (P = 0.058). Oxygen uptake during treadmill running tended to be higher (4.3%) in the Post-race placebo vs. No-race placebo (P = 0.074). Oxygen uptake was 5.4% lower in the Post-race menthol compared to the Post-race placebo (P = 0.018). Minute ventilation during treadmill running was 6.7-7.6% higher in the Post-race placebo compared to No-race placebo, whereas it was 6.6-9.0% lower in the Post-race menthol vs. Post-race placebo (all P ≤ 0.001). The rate of perceived exertion was 7.0% lower in the Post-race menthol vs. Post-race placebo (P = 0.007). CONCLUSIONS: Middle- and long-distance races can subsequently elevate muscle soreness and induce respiratory and metabolic stress, but post-race menthol application to the lower legs can mitigate these responses and reduce exercise exertion in long-distance runners.
Asunto(s)
Mentol , Mialgia , Consumo de Oxígeno , Carrera , Humanos , Mentol/farmacología , Mentol/administración & dosificación , Masculino , Adulto , Carrera/fisiología , Consumo de Oxígeno/efectos de los fármacos , Femenino , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/metabolismo , Adulto JovenRESUMEN
Light-driven photoredox catalysis presents a promising approach for the activation and conversion of methane (CH4) into high value-added chemicals under ambient conditions. However, the high C-H bond dissociation energy of CH4 and the absence of well-defined C-H activation sites on catalysts significantly limit the highly efficient conversion of CH4 toward multicarbon (C2+) hydrocarbons, particularly ethylene (C2H4). Herein, we demonstrate a bimetallic design of Ag nanoparticles (NPs) and Pd single atoms (SAs) on ZnO for the cascade conversion of CH4 into C2H4 with the highest production rate compared with previous works. Mechanistic studies reveal that the synergistic effect of Ag NPs and Pd SAs, upon effecting key bond-breaking and -forming events, lowers the overall energy barrier of the activation process of both CH4 and the resulting C2H6, constituting a truly synergistic catalytic system to facilitate the C2H4 generation. This work offers a novel perspective on the advancement of photocatalytic directional CH4 conversion toward high value-added C2+ hydrocarbons through the subtle design of bimetallic cascade catalyst strategy.
RESUMEN
Photo-driven cross-coupling of o-arylenediamines and alcohols has emerged as an alternative for the synthesis of bio-active benzimidazoles. However, tackling the key problem related to efficient adsorption and activation of both coupling partners over photocatalysts towards activity enhancement remains a challenge. Here, we demonstrate an efficient interface synergy strategy by coupling exposed oxygen vacancies (VO) and Pd Lewis acid sites for benzimidazole and hydrogen (H2) coproduction over Pd-loaded TiO2 nanospheres with the highest photoredox activity compared to previous works so far. The results show that the introduction of VO optimizes the energy band structure and supplies coordinatively unsaturated sites for adsorbing and activating ethanol molecules, affording acetaldehyde active intermediates. Pd acts as a Lewis acid site, enhancing the adsorption of alkaline amine moleculesvia Lewis acid-base pair interactions and driving the condensation process. Furthermore, VO and Pd synergistically promote interfacial charge transfer and separation. This work offers new insightful guidance for the rational design of semiconductor-based photocatalysts with interface synergy at the molecular level towards the high-performance coproduction of renewable fuels and value-added feedstocks.