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Glioblastoma multiforme (GBM) is the most common and aggressive primary malignant human brain tumor. Although comprehensive therapies, including chemotherapy and radiotherapy following surgery, have shown promise in prolonging survival, the prognosis for GBM patients remains poor, with an overall survival rate of only 14.6 months. Chemoresistance is a major obstacle to successful treatment and contributes to relapse and poor survival rates in glioma patients. Therefore, there is an urgent need for novel strategies to overcome chemoresistance and improve treatment outcomes for human glioma patients. Recent studies have shown that the tumor microenvironment plays a key role in chemoresistance. Our study demonstrates that upregulation of HAS2 and subsequent hyaluronan secretion promotes glioma cell proliferation, invasion, and chemoresistance in vitro and in vivo through the c-myc pathway. Targeting HAS2 sensitizes glioma cells to chemotherapeutic agents. Additionally, we found that hypoxia-inducible factor HIF1α regulates HAS2 expression. Together, our findings provide insights into the dysregulation of HAS2 and its role in chemoresistance and suggest potential therapeutic strategies for GBM.
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Proliferación Celular , Resistencia a Antineoplásicos , Subunidad alfa del Factor 1 Inducible por Hipoxia , Proteínas Proto-Oncogénicas c-myc , Regulación hacia Arriba , Animales , Humanos , Ratones , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/genética , Línea Celular Tumoral , Resistencia a Antineoplásicos/genética , Regulación Neoplásica de la Expresión Génica , Glioblastoma/metabolismo , Glioblastoma/patología , Glioblastoma/genética , Glioma/patología , Glioma/metabolismo , Glioma/genética , Hialuronano Sintasas/metabolismo , Hialuronano Sintasas/genética , Ácido Hialurónico/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Ratones Desnudos , Proteínas Proto-Oncogénicas c-myc/metabolismoRESUMEN
Electrochemiluminescence (ECL) efficiency is determined by charge transfer between coreactants and emitters in coreactant systems, which are usually limited by their slow intermolecular charge transfer. In this study, a covalent organic framework (COF) with aldehyde residue was synthesized, and then coreactants were covalently integrated into the skeleton through the postsynthetic modification strategy, resulting in a crystalline coreactant-embedded COF nanoemitter (C-COF). Compared to the pristine COF with an equivalent external coreactant, C-COF exhibited an extraordinary 1008-fold enhancement of ECL intensity due to the rapid intrareticular charge transfer. Significantly, with the pH increase, C-COF shows protonation-induced ECL enhancement for the first ECL peaked at +1.1â V and an opposite trend for the second ECL at +1.4â V, which were attributed to the antedating oxidation of coreactant in framework and COF self-oxidation, respectively. The resulting bimodal oxidation ECL mechanism was rationalized by spectral characterization and density functional theory calculations. The postsynthetic coreactant-embedded nanoemitters present innovative and universal avenues for advancing ECL systems.
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The low cost and high efficiency of microwave-assisted regeneration render it a viable alternative to conventional regeneration methods. To enhance the regeneration performance, we developed a coupled electromagnetic, heat, and mass transfer model to investigate the heat and mass transfer mechanisms of activated carbon during microwave-assisted regeneration. Simulation results demonstrated that the toluene desorption process is governed by temperature distribution. Changing the input power and flow rate can promote the intensity of hot spots and adjust their distribution, respectively, thereby accelerating toluene desorption, inhibiting readsorption, and promoting regeneration efficiency. Ultimately, controlling the input power and flow rate can flexibly adjust toluene emissions to satisfy the processing demands of desorbed toluene. Taken together, this study provides a comprehensive understanding of the heat and mass transfer mechanisms of microwave-assisted regeneration and insights into adsorbent regeneration.
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Carbón Orgánico , Calor , Microondas , Tolueno , Tolueno/química , Adsorción , Carbón Orgánico/química , Modelos QuímicosRESUMEN
Pulmonary fibrosis involves destruction of the lung parenchyma and extracellular matrix deposition. Effective treatments for pulmonary fibrosis are lacking and its pathogenesis is still unclear. Studies have found that epithelial-mesenchymal transition (EMT) of alveolar epithelial cells (AECs) plays an important role in progression of pulmonary fibrosis. Thus, an in-depth exploration of its mechanism might identify new therapeutic targets. In this study, we revealed that a novel circular RNA, MKLN1 (circMKLN1), was significantly elevated in two pulmonary fibrosis models (intraperitoneally with PQ, 50 mg/kg for 7 days, and intratracheally with BLM, 5 mg/kg for 28 days). Additionally, circMKLN1 was positively correlated with the severity of pulmonary fibrosis. Inhibition of circMKLN1 expression significantly reduced collagen deposition and inhibited EMT in AECs. EMT was aggravated after circMKLN1 overexpression in AECs. MiR-26a-5p/miR-26b-5p (miR-26a/b), the targets of circMKLN1, were confirmed by luciferase reporter assays. CircMKLN1 inhibition elevated miR-26a/b expression. Significantly decreased expression of CDK8 (one of the miR-26a/b targets) was observed after inhibition of circMKLN1. EMT was exacerbated again, and CDK8 expression was significantly increased after circMKLN1 inhibition and cotransfection of miR-26a/b inhibitors in AECs. Our research indicated that circMKLN1 promoted CDK8 expression through sponge adsorption of miR-26a/b, which regulates EMT and pulmonary fibrosis. This study provides a theoretical basis for finding new targets or biomarkers in pulmonary fibrosis.
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MicroARNs , Fibrosis Pulmonar , Humanos , Ratones , Animales , Fibrosis Pulmonar/inducido químicamente , Fibrosis Pulmonar/genética , MicroARNs/genética , MicroARNs/metabolismo , ARN Circular/genética , Células Epiteliales Alveolares , Transición Epitelial-Mesenquimal/genética , Quinasa 8 Dependiente de Ciclina/metabolismo , Moléculas de Adhesión Celular/metabolismo , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismoRESUMEN
Efforts to enhance the efficiency of electrocatalysts for the oxygen reduction reaction (ORR) in energy conversion and storage devices present formidable challenges. In this endeavor, M-N4-C single-atom catalysts (MN4) have emerged as promising candidates due to their precise atomic structure and adaptable electronic properties. However, MN4 catalysts inherently introduce oxygen functional groups (OGs), intricately influencing the catalytic process and complicating the identification of active sites. This study employs advanced density functional theory (DFT) calculations to investigate the profound influence of OGs on ORR catalysis within MN4 catalysts (referred to as OGs@MN4, where M represents Fe or Co). We established the following activity order for the 2eORR: for OGs@CoN4: OH@CoN4 > CoN4 > CHO@CoN4 > C-O-C@CoN4 > COC@CoN4 > COOH@CoN4 > CîO@CoN4; for OGs@FeN4: COC@FeN4 > CîO@FeN4 > OH@FeN4 > FeN4 > COOH@FeN4 > CHO@FeN4 > C-O-C@FeN4. Multiple oxygen combinations were constructed and found to be the true origin of MN4 activity (for instance, the overpotential of 2OH@CoN4 as low as 0.07 V). Furthermore, we explored the performance of the OGs@MN4 system through charge and d-band center analysis, revealing the limitations of previous electron-withdrawing/donating strategies. Machine learning analysis, including GBR, GPR, and LINER models, effectively guides the prediction of catalyst performance (with an R2 value of 0.93 for predicting ΔG*OOH_vac in the GBR model). The Eg descriptor was identified as the primary factor characterizing ΔG*OOH_vac (accounting for 62.8%; OGs@CoN4: R2 = 0.9077, OGs@FeN4: R2 = 0.7781). This study unveils the significant impact of OGs on MN4 catalysts and pioneers design and synthesis criteria rooted in Eg. These innovative findings provide valuable insights into understanding the origins of catalytic activity and guiding the design of carbon-based single-atom catalysts, appealing to a broad audience interested in energy conversion technologies and materials science.
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The mortality of patients with severe pneumonia caused by H1N1 infection is closely related to viral replication and cytokine storm. However, the specific mechanisms triggering virus replication and cytokine storm are still not fully elucidated. Here, we identified hypoxia inducible factor-1α (HIF-1α) as one of the major host molecules that facilitates H1N1 virus replication followed by cytokine storm in alveolar epithelial cells. Specifically, HIF-1α protein expression is upregulated after H1N1 infection. Deficiency of HIF-1α attenuates pulmonary injury, viral replication and cytokine storm in vivo. In addition, viral replication and cytokine storm were inhibited after HIF-1α knockdown in vitro. Mechanistically, the invasion of H1N1 virus into alveolar epithelial cells leads to a shift in glucose metabolism to glycolysis, with rapid production of ATP and lactate. Inhibition of glycolysis significantly suppresses viral replication and inflammatory responses. Further analysis revealed that H1N1-induced HIF-1α can promote the expression of hexokinase 2 (HK2), the key enzyme of glycolysis, and then not only provide energy for the rapid replication of H1N1 virus but also produce lactate, which reduces the accumulation of the MAVS/RIG-I complex and inhibits IFN-α/ß production. In conclusion, this study demonstrated that the upregulation of HIF-1α by H1N1 infection augments viral replication and cytokine storm by cellular metabolic reprogramming toward glycolysis mainly through upregulation of HK2, providing a theoretical basis for finding potential targets for the treatment of severe pneumonia caused by H1N1 infection.
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Subtipo H1N1 del Virus de la Influenza A , Humanos , Síndrome de Liberación de Citoquinas , Reprogramación Metabólica , Replicación Viral , LactatosRESUMEN
Prion diseases are a group of fatal neurodegenerative diseases caused by the misfolding and aggregation of prion protein (PrP), and the inhibition of PrP aggregation is one of the most effective therapeutic strategies. Proanthocyanidin B2 (PB2) and B3 (PB3), the effective natural antioxidants have been evaluated for the inhibition of amyloid-related protein aggregation. Since PrP has similar aggregation mechanism with other amyloid-related proteins, will PB2 and PB3 affect the aggregation of PrP? In this paper, experimental and molecular dynamics (MD) simulation methods were combined to investigate the influence of PB2 and PB3 on PrP aggregation. Thioflavin T assays showed PB2 and PB3 could inhibit PrP aggregation in a concentrate-dependent manner in vitro. To understand the underlying mechanism, we performed 400 ns all-atom MD simulations. The results suggested PB2 could stabilize the α2 C-terminus and the hydrophobic core of protein by stabilizing two important salt bridges R156-E196 and R156-D202, and consequently made global structure of protein more stable. Surprisingly, PB3 could not stabilize PrP, which may inhibit PrP aggregation through a different mechanism. Since dimerization is the first step of aggregation, will PB3 inhibit PrP aggregation by inhibiting the dimerization? To verify our assumption, we then explored the effect of PB3 on protein dimerization by performing 800 ns MD simulations. The results suggested PB3 could reduce the residue contacts and hydrogen bonds between two monomers, preventing dimerization process of PrP. The possible inhibition mechanism of PB2 and PB3 on PrP aggregation could provide useful information for drug development against prion diseases.Communicated by Ramaswamy H. Sarma.
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Enfermedades por Prión , Priones , Proantocianidinas , Humanos , Simulación de Dinámica Molecular , Proantocianidinas/farmacología , Proteínas Priónicas/químicaRESUMEN
BACKGROUND: Early identification of sepsis improves the survival rate; however, it is one of the most challenging tasks for physicians, especially since symptoms are easily confused with those of systemic inflammatory response syndrome (SIRS). Our aim was to explore biomarkers for early identification of sepsis that would aid in its differential diagnosis. METHODS: Eight patients with SIRS, eight with sepsis, and eight healthy controls were included in this study. Metabolites were screened using gas chromatography-mass spectrometry (GC-MS). Metabolism profiles were analyzed using the untargeted database of GC-MS from Lumingbio (LUG) database, and metabolic pathways were enriched based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) database. The S-plot was used to screen the potential biomarkers distinguishing between patients with SIRS, sepsis, and healthy controls. Receiver operating characteristic (ROC) curve analysis was used to evaluate potential biomarkers between SIRS and sepsis patients. Correlation analysis was used to measure the degree of correlation between differential metabolites. Correlation analysis between 2-deoxy-d-erythro-pentofuranose-5-phosphate and clinical indicators was performed. RESULTS: There were 51 metabolites that were distributed in the SIRS group, and they were enriched with 18 metabolic pathways compared with healthy controls. Moreover, 63 metabolites in the sepsis group were significantly distinguishable compared to the healthy controls, and were associated with 21 metabolic pathways. Methyl 3-o-acetyl-d-galactopyranoside and N-acetylputrescine were found to be candidate biomarkers for distinguishing between SIRS, sepsis, and healthy controls using the S-plot model. Only four differential metabolites, including 2-deoxy-d-erythro-pentofuranose-5-phosphate, terbutaline, allantoic acid, and homovanillic acid (HVA), were enriched in the dopaminergic synapse and tyrosine metabolism pathways when sepsis patients were compared with SIRS patients. The Area Under Curve (AUC) of 2-deoxy-d-erythro-pentofuranose-5-phosphate was 0.9297, indicating a strong diagnostic ability for sepsis. A significant negative correlation was identified between 2-deoxy-d-erythro-pentofuranose-5-phosphate and lactate (r = -0.8756, p = 0.0044). CONCLUSIONS: Methyl 3-o-acetyl-d-galactopyranoside and N-acetylputrescine may be used as candidate biomarkers to distinguish SIRS and sepsis patients from healthy controls using GC-MS. 2-deoxy-d-erythro-pentofuranose-5-phosphate may be the candidate biomarker to distinguish sepsis from SIRS. Our study explored candidate biomarkers for the early identification of sepsis, which is vital for improving its prognosis.
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The O-carbamoyltransferase VtdB catalyzes the carbamoylation of venturicidin B, which is essential for the biosynthesis of the antibiotic venturicidin A. Here, the crystal structures of VtdB and VtdB in complex with the intermediate carbamoyladenylate (VtdBCAO) were determined at resolutions of 2.99 Å and 2.90 Å, respectively. The structures resemble the conserved YrdC-like and specific Kae1-like domains. A magnesium ion and the intermediate carbamoyladenylate were also observed in the Kae1-like domain of VtdB. The structure of VtdBCAO in complex with the substrate venturicidin B was modeled by a molecular docking method to better understand the substrate binding mode, revealing a novel venturicidin B binding pocket.
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Streptomyces , Simulación del Acoplamiento Molecular , Sitios de Unión , Cristalografía por Rayos X , Especificidad por SustratoRESUMEN
Paraquat (PQ) is a bipyridine herbicide and oral exposure is the main way of PQ exposure with a very high mortality. At present, it is believed that large number of oxygen free radicals are generated and cause lipid peroxidation of tissue and organ cell membranes after PQ is absorbed. PQ exposure could cause multiple organ dysfunction, among which acute lung injury is the most common and most serious. However, its specific mechanism is still unclear. In this study, the C57BL/6J mouse (alveolar epithelial cell-specific knockout HIF-1α) model of acute lung injury (40 mg/kg PQ) at several time pointes and a model of acute type II alveolar epithelial cell (A549, 800 µM PQ) injury constructed. The oxidative stress (ROS, MDA) and inflammatory response (IL-1ß, IL-6, TNF-α) were significantly inhibited in the alveolar epithelial cell-specific knockout of HIF-1α mice and siRNA technology to inhibit HIF-1α in alveolar epithelial cells. Further proteomic analysis showed that the expression of Rac2 protein, which is closely related to oxidative stress, was significantly increased after PQ exposure. And the inhibition of Rac2 expression in vitro significantly alleviated PQ-induced oxidative stress and inflammatory response. The expression of Rac2 protein was regulated by HIF-1α. The above suggests that HIF-1α may promote oxidative stress and inflammatory response in alveolar epithelial cells by regulating the expression of Rac2, and then participate in the promotion of PQ exposure-induced acute lung injury.
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Lesión Pulmonar Aguda , Subunidad alfa del Factor 1 Inducible por Hipoxia , Animales , Ratones , Lesión Pulmonar Aguda/inducido químicamente , Lesión Pulmonar Aguda/metabolismo , Pulmón/metabolismo , Ratones Endogámicos C57BL , FN-kappa B/metabolismo , Paraquat/toxicidad , Proteómica , Subunidad alfa del Factor 1 Inducible por Hipoxia/efectos de los fármacos , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Proteínas de Unión al GTP rac/metabolismo , Proteína RCA2 de Unión a GTPRESUMEN
Paraquat (PQ) is an efficient herbicide but leads to high mortality with no antidote in mammals. PQ produces reactive oxygen species (ROS), leading to epithelial-mesenchymal transition (EMT) for pulmonary fibrosis in type II alveolar (AT II) cells. Intriguingly, strategies reducing ROS exhibit limited therapeutic effects, indicating other targets existing for PQ toxicity. Herein we report that PQ is also an agonist for STIM1 that increases intracellular calcium levels. Particularly, PQ promotes STIM1 puncta formation and association with TRPC1 or ORAI for extracellular calcium entry and thus intracellular calcium influx. Further studies reveal the importance of P584&Y586 residues in STIM1 for PQ association that facilitates STIM1 binding to TRPC1. Consequently, the STIM1-TRPC1 route facilitates PQ-induced EMT for pulmonary fibrosis as well as cell death. Our results demonstrate that PQ is an agonist of STIM1 that induces extracellular calcium entry, increases intracellular calcium levels, and thus promotes EMT in AT II cells.
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Paraquat , Fibrosis Pulmonar , Animales , Paraquat/farmacología , Fibrosis Pulmonar/inducido químicamente , Fibrosis Pulmonar/metabolismo , Calcio , Especies Reactivas de Oxígeno , Transición Epitelial-Mesenquimal , MamíferosRESUMEN
The global coronavirus disease 2019 epidemic is still in a pandemic state. Aging population with underlying diseases is prone to become severe, and have a higher mortality. The treatment capacity of the critical care department directly determines the treatment success rate of critical illness. At present, there is still a certain gap between domestic and foreign countries in intensive care unit (ICU), which is not only in the allocation of medical staff, but also in the beds and settings. The current medical model cannot fully meet the needs of development. The experience and lessons of many major public health emergencies suggested that "dual track of peace and war" approach in discipline construction of critical care is the best medical model. Following the concept of "combination of peace and war", strengthening the discipline construction of critical care department in municipal and district designated hospitals, allocating reasonable standard ICU, step-down ICU and combat readiness ICU, establishing rapid response team, and strengthening regular training and scientific management may be the key measures to deal with the epidemic.
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COVID-19 , Pandemias , Anciano , Cuidados Críticos , Hospitales , Humanos , Unidades de Cuidados Intensivos , Pandemias/prevención & controlRESUMEN
Visna/Maedi virus (VMV) is a neglected pathogen that damages sheep and goats' nervous and respiratory systems. The virus was discovered 80 years ago and has been endemic in China for nearly four decades; nevertheless, there is little information regarding Chinese isolates' genotypes and genomic characteristics. In this study, the proviral DNA of strains isolated in 1985 and 1994 were extracted, and the proviral DNA was subjected to Illumina sequencing combined with Sanger sequencing of poor coverage regions. The results showed that the two isolates were clustered with genotype A2 and shared 78.3%-89.1% similarity to reference VMV genome sequences, with the highest similarity (88.7%-89.1%) to the USA strain USMARC-200212120-r (accession no. MT993908.1) and lowest similarity (78.3%-78.5%) to the Italian strain SRLV009 (accession no. MG554409.1). A maximum-likelihood tree showed that the Chinese VMV strains and the USA strain 1150 (accession no. MH916859.1) comprise a monophyletic group with a short tree branch. Our data filled the gap in genomic analysis and viral evolution in Chinese VMV strains, and would be benefit China's source-tracing and eradication program development in China.
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Hepatitis E virus (HEV) causes infections in humans and a wide range of animal hosts. Wild boar is an important natural reservoir of HEV genotypes 3−6 (HEV-3−HEV-6), but comparative analysis of HEV infections in both feral and farmed wild boars remains limited. In this study, samples from 599 wild boars were collected during 2017−2020, including 121 feral wild boars (collected 121 fecal, 121 serum, and 89 liver samples) and 478 farmed wild boars (collected 478 fecal and 478 serum samples). The presence of anti-HEV IgG antibodies were detected by the HEV-IgG enzyme-linked immunosorbent assay (ELISA) kit. HEV RNA was detected by reverse transcription polymerase chain reaction (RT-PCR), targeting the partial ORF1 genes from fecal and liver samples, and the obtained genes were further genotyped by phylogenetic analysis. The results showed that 76.2% (95% CI 72.1−79.9) of farmed wild boars tested anti-HEV IgG seropositive, higher than that in feral wild boars (42.1%, 95% CI 33.2−51.5, p < 0.001). HEV seropositivity increased with age. Wild boar HEV infection presented a significant geographical difference (p < 0.001), but not between sex (p = 0.656) and age (p = 0.347). HEV RNA in fecal samples was detected in 13 (2.2%, 95% CI 1.2−3.7) out of 599 wild boars: 0.8% (95% CI 0.0−4.5, 1/121) of feral wild boars and 2.5% (95% CI 1.3−4.3, 12/478) of farmed wild boars. Phylogenetic analysis showed that all these viruses belonged to genotype HEV-4, and further grouped into sub-genotypes HEV-4a, HEV-4d, and HEV-4h, of which HEV-4a was first discovered in the wild boar populations in China. Our results suggested that farms could be a setting for amplification of HEV. The risk of HEV zoonotic transmission via rearing and consumption of farmed wild boars should be further assessed.
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Virus de la Hepatitis E , Hepatitis E , Enfermedades de los Porcinos , Porcinos , Animales , Humanos , Sus scrofa , Prevalencia , Filogenia , Granjas , ARN Viral/genética , ARN Viral/análisis , Enfermedades de los Porcinos/epidemiología , Hepatitis E/epidemiología , Hepatitis E/veterinaria , Anticuerpos Antihepatitis , China/epidemiologíaRESUMEN
INTRODUCTION: Drug-target thermodynamic and kinetic information have perennially important roles in drug design. The prediction of protein-ligand unbinding, which can provide important kinetic information, in experiments continues to face great challenges. Uncovering protein-ligand unbinding through molecular dynamics simulations has become efficient and inexpensive with the progress and enhancement of computing power and sampling methods. AREAS COVERED: In this review, various sampling methods for protein-ligand unbinding and their basic principles are firstly briefly introduced. Then, their applications in predicting aspects of protein-ligand unbinding, including unbinding pathways, dissociation rate constants, residence time and binding affinity, are discussed. EXPERT OPINION: Although various sampling methods have been successfully applied in numerous systems, they still have shortcomings and deficiencies. Most enhanced sampling methods require researchers to possess a wealth of prior knowledge of collective variables or reaction coordinates. In addition, most systems studied at present are relatively simple, and the study of complex systems in real drug research remains greatly challenging. Through the combination of machine learning and enhanced sampling methods, prediction accuracy can be further improved, and some problems encountered in complex systems also may be solved.
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Simulación de Dinámica Molecular , Proteínas , Descubrimiento de Drogas , Humanos , Cinética , Ligandos , Unión Proteica , Proteínas/metabolismo , TermodinámicaRESUMEN
Paraquat (PQ) and diquat (DQ), two highly efficient herbicides sharing similar chemical backbone, both induce reactive oxygen species and are highly toxic to humans and livestock, however, PQ but not DQ poisoning result in pulmonary fibrosis, the leading cause of high mortality rate in patients suffering PQ toxicity. Understanding the unique mechanism of PQ different from DQ therefore would provide potential strategies to reduce PQ-induced pulmonary fibrosis. Here, we identified that PQ but not DQ continuously upregulates TGF-ß expression in alveolar type II (AT II) cells. Importantly, such high expression of TGF-ß increases cytosolic calcium levels and further promotes the activation of calcineurin-NFAT axis. TGF-ß mainly activates NFATc1 and NFATc2, but not NFATc3 or NFATc4. Administration of the inhibitors targeting cytosolic calcium or calcineurin largely reverses PQ-induced epithelial-mesenchymal transition (EMT), whereas DQ has little effects on activation of NFAT and EMT. Ultimately, PQ poisoned patients exhibit significantly reduced blood calcium levels compared to DQ poisoning, possibly via the large usage of calcium by AT II cells. All in all, we found a vicious cycle that the upregulated TGF-ß in PQ-induced EMT further aggravates EMT via promotion of the calcium-calcineurin axis, which could be potential drug targets for treating PQ-induced pulmonary fibrosis.
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Viruses depend on host cellular metabolism to provide the energy and biosynthetic building blocks required for their replication. In this study, we observed that influenza A virus (H1N1), a single-stranded, negative-sense RNA virus with an eight-segmented genome, enhanced glycolysis both in mouse lung tissues and in human lung epithelial (A549) cells. In detail, the expression of hexokinase 2 (HK2), the first enzyme in glycolysis, was upregulated in H1N1-infected A549 cells, and the expression of pyruvate kinase M2 (PKM2) and pyruvate dehydrogenase kinase 3 (PDK3) was upregulated in H1N1-infected mouse lung tissues. Pharmacologically inhibiting the glycolytic pathway or targeting hypoxia-inducible factor 1 (HIF-1), the central transcriptional factor critical for glycolysis, significantly reduced H1N1 replication, revealing a requirement for glycolysis during H1N1 infection. In addition, pharmacologically enhancing the glycolytic pathway further promoted H1N1 replication. Furthermore, the change of H1N1 replication upon glycolysis inhibition or enhancement was independent of interferon signaling. Taken together, these findings suggest that influenza A virus induces the glycolytic pathway and thus facilitates efficient viral replication. This study raises the possibility that metabolic inhibitors, such as those that target glycolysis, could be used to treat influenza A virus infection in the future.
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Subtipo H1N1 del Virus de la Influenza A , Virus de la Influenza A , Células A549 , Animales , Glucólisis , Humanos , Ratones , Replicación ViralRESUMEN
H2O2 generation by 2-electron oxygen electroreduction reaction (2eORR) has attracted great attention as an alternative to the industry-dominant anthraquinone process. Electro-Fenton (EF) process, which relies on the H2O2 electrogeneration, is regarded as an important environmental application of H2O2 generation by 2eORR. However, its application is hindered by the relatively expensive electrode materials. Proposing cathode materials with low cost and facile synthetic procedures are the priority to advance the EF process. In this work, a composite cathode structure that uses graphitic granular bamboo-based biochar (GB) and stainless steel (SS) mesh (GBSS) is proposed, where SS mesh functions as current distributor and GB supports synergistic H2O2 electrogeneration and activation. The graphitic carbon makes GB conductive and the oxygen-containing groups serve as active sites for H2O2 production. 11.3 mg/L H2O2 was produced from 2.0 g GB at 50 mA after 50 min under neutral pH without external O2/air supply. The O-doped biochar further increased the H2O2 yield to 18.3 mg/L under same conditions. The GBSS electrode is also effective for H2O2 activation to generate ·OH, especially under neutral pH. Ultimately, a neutral Fe-free EF process enabled by GBSS cathode is effective for removal of various model organic pollutants (reactive blue 19, orange II, 4-nitrophenol) within 120 min, and for their partial mineralization (48.4% to 63.5%). Long-term stability of the GBSS electrode for H2O2 electrogeneration, H2O2 activation, and pollutants degradation were also examined and analyzed. This work offers a promising application for biomass waste for removals of organic pollutants in neutral Fe-free EF process.
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Idiopathic pulmonary fibrosis (IPF) is a chronic, fatal lung disease characterized by progressive and non-reversible abnormal matrix deposition in lung parenchyma. Myofibroblasts originating mainly from resident fibroblasts via fibroblast-to-myofibroblast transition (FMT) are the dominant collagen-producing cells in pulmonary fibrosis. N6-methyladenosine (m6A) modification has been implicated in various biological processes. However, the role of m6A modification in pulmonary fibrosis remains elusive. In this study, we reveal that m6A modification is upregulated in a bleomycin (BLM)-induced pulmonary fibrosis mouse model, FMT-derived myofibroblasts, and IPF patient lung samples. Lowering m6A levels through silencing methyltransferase-like 3 (METTL3) inhibits the FMT process in vitro and in vivo. Mechanistically, KCNH6 is involved in the m6A-regulated FMT process. m6A modification regulates the expression of KCNH6 by modulating its translation in a YTH-domain family 1 (YTHDF1)-dependent manner. Together, our study highlights the critical role of m6A modification in pulmonary fibrosis. Manipulation of m6A modification through targeting METTL3 may become a promising strategy for the treatment of pulmonary fibrosis.
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Fibrosis Pulmonar Idiopática , Miofibroblastos , Animales , Bleomicina/efectos adversos , Canales de Potasio Éter-A-Go-Go/efectos adversos , Canales de Potasio Éter-A-Go-Go/metabolismo , Fibroblastos/metabolismo , Humanos , Fibrosis Pulmonar Idiopática/inducido químicamente , Fibrosis Pulmonar Idiopática/genética , Fibrosis Pulmonar Idiopática/terapia , Pulmón/metabolismo , Metiltransferasas/metabolismo , Ratones , Ratones Endogámicos C57BL , Miofibroblastos/metabolismo , Biosíntesis de ProteínasRESUMEN
Pulmonary fibrosis is the primary reason for mortality in patients with paraquat (PQ) poisoning. Our previous study demonstrated that epithelialmesenchymal transition (EMT) had a role in PQinduced pulmonary fibrosis. However, the role of endoplasmic reticulum (ER) stress in PQinduced EMT remains clear. The present study aimed to determine the role of ER stress in EMT in PQinduced pulmonary fibrosis. A549 and RLE6TN cells were incubated with LY294002 (a PI3K inhibitor) or transfected with protein kinase RNAlike ER kinase (PERK) small interfering RNA (si) for 24 h prior to being exposed to PQ. Next, the expression levels of ER stressrelated proteins, PI3K/AKT/GSK3ß signaling pathwayrelated proteins and EMTrelated markers were analyzed by performing western blotting, reverse transcriptionquantitative PCR and immunofluorescence assays. The results of the present study revealed that the protein expression levels of PERK, phosphorylated (p)PERK, peukaryotic initiation factor 2 (eIF2)α were significantly upregulated in the PQ group, whereas pPI3K, pAKT and pGSK3ß were significantly upregulated in the sicontrol + PQ group compared with the sicontrol group. In vitro, following transfection with siPERK or treatment with the PI3K inhibitor, the protein expression levels of Ecadherin (an epithelial marker) were upregulated, whereas the protein expression levels of αSMA (a mesenchymal marker) were downregulated. Immunofluorescence analysis revealed that the levels of Ecadherin were markedly upregulated, whereas the levels of αSMA were notably downregulated following transfection with siPERK compared with the sicontrol group. The results of wound healing assay demonstrated that cell migration in the siPERK + PQ group was markedly decreased compared with the sicontrol + PQ group. These indicated that PQinduced EMT was suppressed after silencing PERK. The expression levels of pGSK3ß, pAKT and pPI3K were also markedly downregulated in the siPERK + PQ group compared with the sicontrol + PQ group. In conclusion, the findings of the present study suggested that ER stress may promote EMT through the PERK signaling pathway in PQinduced pulmonary fibrosis. Thus, ER stress may represent a potential therapeutic target for PQinduced pulmonary fibrosis.