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Background: Although the thymus undergoes degeneration with the advancement of age, recent studies have continuously revealed that the thymus possesses the potential for regeneration and may reverse this aging trend. Furthermore, an increasing number of studies indicate an association between thymus function and immunotherapy. Considering that lung cancer patients typically undergo chest computed tomography (CT) scans during treatment, this provides convenient conditions for us to observe thymic remodeling through imaging data. Therefore, exploring the changes in the thymus on CT images is of great significance for understanding its relationship with the efficacy of immunotherapy in non-small cell lung cancer (NSCLC) patients. This study investigated the CT imaging characteristics of thymic density changes in patients with advanced NSCLC after immunotherapy. The primary objective was to determine whether changes in thymic density are predictors of response to immunotherapy in patients with NSCLC. Methods: A total of 412 patients with advanced NSCLC who underwent immunotherapy were included. Thymic density measurements were taken initially and after immunotherapy, with the annualized change calculated. Comprehensive analysis, including disease progression, survival, and subgroup assessments, was conducted. The primary outcome was overall survival (OS), and the secondary outcomes were progression-free survival (PFS), objective response rate (ORR) and disease control rate (DCR). Results: The annual change in density of the thymic region ranged from -108 to 108 HU after the initiation of ICIs. Patients were categorized into "loss" or "non-loss" groups (210 vs. 202) based on thymic density changes. Analysis of short-term progression of solid tumors revealed no statistically significant differences in ORR (P=0.55) and DCR (P=0.67) between the two groups. Throughout the entire follow-up period, 41 patients (19.5%) in the "loss" group and 64 patients (31.7%) in the "non-loss" group died. Thymic density reduction was not associated with PFS (P=0.08), but it was positively associated with increased OS (P=0.003). The results were consistent across subgroups. Conclusions: Thymic density changes were observed in nearly all NSCLC patients undergoing immunotherapy, with decreased density associated with longer OS. These findings suggest a potential association between thymic density changes and immune efficacy in NSCLC immunotherapy.
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Variants in the poorly characterised oncoprotein, MORC2, a chromatin remodelling ATPase, lead to defects in epigenetic regulation and DNA damage response. The C-terminal domain (CTD) of MORC2, frequently phosphorylated in DNA damage, promotes cancer progression, but its role in chromatin remodelling remains unclear. Here, we report a molecular characterisation of full-length, phosphorylated MORC2, demonstrating its preference for binding open chromatin and functioning as a DNA sliding clamp. We identified a phosphate interacting motif within the CTD that dictates ATP hydrolysis rate and cooperative DNA binding. The DNA binding impacts several structural domains within the ATPase region. We provide the first visual proof that MORC2 induces chromatin remodelling through ATP hydrolysis-dependent DNA compaction, regulated by its phosphorylation state. These findings highlight phosphorylation of MORC2 CTD as a key modulator of chromatin remodelling, presenting it as a potential therapeutic target.
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The present study took L2 English learners of different levels in China as subjects to investigate the relationship between collocational familiarity and collocational frequency as well as L1-L2 congruency, and then explored the development of the above relationship as L2 proficiency develops. The results showed that: a moderate positive correlation existed between familiarity and frequency, and the correlation increased with proficiency; a moderate positive correlation also existed between familiarity and congruency, but the correlation decreased with proficiency. Based on previous studies and the present findings, the research group infer that: low familiarity collocations tend to be represented and processed in analytic way and same-translation effect helps accelerate the semantic access of congruent collocations in this process; with the increase in learners' proficiency, collocation familiarity develops from low to high with frequency effect; high familiarity collocations tend to be represented and processed in holistic way to have direct semantic access; furthermore, learners of two levels have two kinds of collocational representation and semantic access, but low-level learners show more analytic representation and indirect semantic access because of having more low familiarity collocations in the mental lexicon.
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BACKGROUND: Due to insufficient near-field resolution and artifacts, it is challenging to evaluate the left ventricular apical perfusion with phased-array probes. By combining high-frequency linear probe and contrast-enhanced ultrasound (CEUS), imaging of apical myocardial perfusion could be improved. The study aims to evaluate the preliminary application of CEUS by high-frequency linear probes to assess the apical perfusion. METHODS: The study enrolled retrospectively 91 patients to test the feasibility of the novel method. In protocol 1, patients were stratified into a group with left anterior descending artery (LAD) stenosis (N = 40) and a group without LAD stenosis or coronary artery disease (N = 41) based on the degree of coronary artery narrowing, quantified by >50% stenosis in coronary angiography. Receiver operating characteristics (ROC) analysis was performed to test the diagnostic value of perfusion parameters. In protocol 2, the reproducibility of high-frequency linear probe in apical perfusion analysis was compared with the conventional phased-array probe in 30 patients. RESULTS: (1) The novel method is feasible in 81(89.01%) patients. (2) In protocol 1, to detect LAD stenosis, the best cut-off of ß, T, A, and MBF were 10.32, 3.28, 9.39, and 4.99, respectively. Area under the curve of ß, T, A, and MBF were .880, .881, .761, and .880, respectively. (3) In protocol 2, compared with phased-array probe, the quantitative analysis of high-frequency linear probe is of high reproducibility and could get good curve fitting (R2 = .29 vs. R2 = .71, P < .01). CONCLUSION: Observation of apical perfusion using this method is feasible and quantitative analysis allows an accurate and convenient identification of LAD stenosis. This method provides an alternative for patients who have difficulties in visualizing the apical region with a phased-array probe.
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Meios de Contraste , Estudos de Viabilidade , Humanos , Masculino , Feminino , Reprodutibilidade dos Testes , Estudos Retrospectivos , Pessoa de Meia-Idade , Imagem de Perfusão do Miocárdio/métodos , Ecocardiografia/métodos , Aumento da Imagem/métodos , Idoso , Sensibilidade e Especificidade , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologia , Estenose Coronária/fisiopatologia , Estenose Coronária/diagnóstico por imagem , Desenho de EquipamentoRESUMO
Background: Immune checkpoint inhibitors (ICIs) have left a deep impression in the treatment of non-small cell lung cancer (NSCLC), however, not all patients benefit from it. The purpose of this study was to investigate the prognostic value of baseline bone mineral density (BMD) derived from chest computed tomography (CT) scans in NSCLC patients treated with ICIs. Methods: This study included patients with advanced NSCLC who underwent ICI treatment at the Wuhan Union Hospital from March 2020 to October 2022. Baseline BMD was evaluated at non-contrast chest CT at the level of first lumbar vertebra. Patients were divided into BMD-lower group and BMD-higher group according to the optimal cutoff value calculated by X-tile software. Baseline characteristics of the two groups were compared and variables between the two groups were balanced by propensity score matching (PSM) analysis. We calculated the objective response rate (ORR) and disease control rate (DCR) of the two groups and analyzed overall survival (OS) and progression-free survival (PFS) using BMD and other clinical indexes through Cox regression models and Kaplan-Meier survival curves. Results: A total of 479 patients were included in this study, and all patients were divided into BMD-lower group (n=270) and BMD-higher group (n=209). After PSM analysis, each group consisted of 150 patients. ORR (43.3% vs. 43.5% before PSM, P = 0.964; 44.7% vs. 44.7% after PSM, P = 1.000) and DCR (91.1% vs. 94.3% before PSM, P = 0.195; 93.3% vs. 96.7% after PSM, P =0.190) were similar in two groups. There was no statistically significant relationship between BMD degree and PFS before (16.0 months vs. 18.0 months, P = 0.067) and after PSM analysis (17.0 months vs. 19.0 months, P = 0.095). However, lower BMD was associated with shorter OS both before (20.5 months vs. 23.0 months, P< 0.001) and after PSM analysis (20.0 months vs. 23.0 months, P = 0.008). Conclusion: Lower baseline BMD is associated with worse clinical outcomes in NSCLC patients treated with ICIs. As a reliable and easily obtained individual prognostic biomarker, BMD can become a routine detection indicator before immunotherapy.
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Densidade Óssea , Carcinoma Pulmonar de Células não Pequenas , Inibidores de Checkpoint Imunológico , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Masculino , Inibidores de Checkpoint Imunológico/uso terapêutico , Inibidores de Checkpoint Imunológico/efeitos adversos , Feminino , Pessoa de Meia-Idade , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/mortalidade , Densidade Óssea/efeitos dos fármacos , Idoso , Prognóstico , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , AdultoRESUMO
Cancer metastasis is the main cause of cancer-related deaths and involves the interaction between tumor cells and neutrophils. In this study, we developed activated neutrophil membrane-coated nanoparticles (aNEM NPs) as nanodecoys to block neutrophil-mediated cancer metastasis. The aNEM NPs were fabricated by cloaking poly(lactic acid) nanoparticles with membranes derived from activated neutrophils and inherited the functional proteins of activated neutrophils. We demonstrated that aNEM NPs could interfere with the recruitment of neutrophils to the primary tumor and premetastatic niches, inhibit the adhesion of neutrophils to tumor vascular endothelium and circulating tumor cells (CTCs), and disrupt the formation of CTC-neutrophil clusters in vitro and in vivo. In 4T1-bearing mice, aNEM NPs could effectively reduce breast cancer metastasis to various organs in mice. Our results suggest that aNEM NPs are a promising nanomedicine for preventing or treating cancer metastasis by acting as neutrophil nanodecoys.
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Células Neoplásicas Circulantes , Neutrófilos , Animais , Camundongos , Neutrófilos/metabolismo , Células Neoplásicas Circulantes/patologia , Linhagem Celular TumoralRESUMO
Heart failure (HF), with its high morbidity and mortality, remains a global public health issue. Right ventricular (RV) dysfunction is a sign of deterioration in the natural history of HF, and a thorough evaluation of the relationship between RV contractility and its afterload through RV-pulmonary arterial (RV-PA) coupling can aid in accurately assessing overall RV function. The ratio of RV end-systolic elastance (Ees) to pulmonary arterial elastance (Ea) invasively measured by right heart catheterization served as the gold standard for evaluating RV-PA coupling. An echocardiographic index termed tricuspid annular plane systolic excursion/pulmonary artery systolic pressure (TAPSE/PASP) has been shown to correlate well with Ees/Ea. TAPSE/PASP is recognized as a non-invasive surrogate of RV-PA coupling and has been extensively studied in patients with HF. This review briefly describes the methods of assessing RV-PA coupling, mainly discussing echocardiography, summarizes the clinical utility of TAPSE/PASP in patients with different HF types, and provides an overview of the available literature.
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Ecocardiografia , Insuficiência Cardíaca , Ventrículos do Coração , Artéria Pulmonar , Disfunção Ventricular Direita , Função Ventricular Direita , Humanos , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/diagnóstico , Artéria Pulmonar/fisiopatologia , Artéria Pulmonar/diagnóstico por imagem , Função Ventricular Direita/fisiologia , Ecocardiografia/métodos , Disfunção Ventricular Direita/fisiopatologia , Disfunção Ventricular Direita/diagnóstico por imagem , Disfunção Ventricular Direita/diagnóstico , Ventrículos do Coração/fisiopatologia , Ventrículos do Coração/diagnóstico por imagem , Cateterismo Cardíaco/métodosRESUMO
Motivated by the effect of symmetry breaking in cuprates superconductors YBa[Formula: see text]Cu[Formula: see text]O[Formula: see text], we employ the renormalized mean-field theory to study the presence of uniform superconducting and charge-ordered states in two anisotropic t-J-U models, either with hopping strength anisotropy or antiferromagnetic interaction anisotropy. In the case of uniform superconducting state, compared with the isotropic t-J-U model with only [Formula: see text]-wave superconducting state, there is an additional s-wave superconducting state in the model with hopping strength anisotropy. Meanwhile, the hopping anisotropy may enhance the critical Coulomb interaction [Formula: see text] at the Mott insulator to the Gossamer superconductor transition point, and strong hopping anisotropy may weaken the superconducting state. In the case of a charge-ordered state, hopping anisotropy may suppress the amplitude of the charge density waves and pair density waves, which originate from local Coulomb interactions. These results indicate that the effects of hopping anisotropy and local Coulomb interactions are competitive. Moreover, the antiferromagnetic interaction anisotropy only weakly suppresses the superconducting gap and density wave amplitude. Our results show that the t-J-U model with hopping anisotropy is qualitatively consistent with experimental superconducting pair symmetry and charge density waves in the YBa[Formula: see text]Cu[Formula: see text]O[Formula: see text] system.
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Cell fate decisions and transitions are common in almost all developmental processes. Therefore, it is important to identify the decision-making mechanisms and important individual molecules behind the fate decision processes. In this paper, we propose an interpretable strategy based on systematic perturbation, unsupervised hierarchical cluster analysis (HCA), machine learning (ML), and Shapley additive explanation (SHAP) analysis for inferring the contribution and importance of individual molecules in cell fate decision and transition processes. In order to verify feasibility of the approach, we apply it to the core epithelial to mesenchymal transition (EMT)-metastasis network. The key factors identified in EMT-metastasis are consistent with relevant experimental observations. The approach presented here can be applied to other biological networks to identify important factors related to cell fate decisions and transitions.
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Transição Epitelial-Mesenquimal , Aprendizado de MáquinaRESUMO
BACKGROUND: Hemorrhage, in particular noncompressible hemorrhage, is the leading cause of casualties in combat trauma and civilian trauma. Although systemic agents can stop bleeding at both inaccessible and accessible injury sites, the application of systemic hemostats in clinics is strictly limited by the nontargeting ability of hemostats and their subsequent potential for thromboembolic complications. OBJECTIVES: To engineer an anticoagulant/procoagulant self-converting and bleeding site-targeting systemic nanohemostat to rapidly control noncompressible bleeding without thrombosis risk. METHODS: A multiscale computer simulation was taken to guide the self-assembly of sulindac (SUL, a prodrug of the antiplatelets agent) and poly-L-lysine (a cation polymer with platelets activation ability) for forming poly-L-lysine/SUL nanoparticles (PSNs). In vitro platelet-adhering ability, platelet activation effect, and hemostasis activity of PSNs were evaluated. Then, the biosafety, level of thrombosis, targeting ability, and hemostasis effect of systemic applied PSNs were carefully evaluated in various hemorrhage models. RESULTS: PSNs were successfully prepared and showed good platelet adhesion and activation in vitro. The bleeding site-targeting ability and hemostatic efficiency in different bleeding models were leveled up by PSNs markedly compared with vitamin K and etamsylate in vivo. SUL in PSNs could be metabolized into sulindac sulfide at clot sites in 4 hours for antiplatelet aggregation, thus reducing thrombotic risk compared with other hemostatic agents, via the ingenious utilization of prodrug metabolism in terms of time intervals and the adhesion on platelets. CONCLUSION: PSNs are expected to be a low-cost, safe, efficient, clinically translatable first-aid hemostat for first-aid scenarios.
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Hemostáticos , Pró-Fármacos , Trombose , Humanos , Anticoagulantes/uso terapêutico , Simulação por Computador , Polilisina/farmacologia , Polilisina/uso terapêutico , Pró-Fármacos/farmacologia , Pró-Fármacos/uso terapêutico , Hemorragia/induzido quimicamente , Hemorragia/tratamento farmacológico , Hemostasia , Hemostáticos/uso terapêutico , Trombose/tratamento farmacológicoRESUMO
The oral route is the most preferred route for systemic and local drug delivery. However, the oral drug delivery system faces the harsh physiological and physicochemical environment of the gastrointestinal tract, which limits the bioavailability and targeted design of oral drug delivery system. Innovative pharmaceutical approaches including nanoparticulate formulations, biomimetic drug formulations, and microfabricated devices have been explored to optimize drug targeting and bioavailability. In this review, the anatomical factors, biochemical factors, and physiology factors that influence delivering drug via oral route are discussed and recent advance in conventional and novel oral drug delivery approaches for improving drug bioavailability and targeting ability are highlighted. We also address the challenges and opportunities of oral drug delivery systems in future.
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Lenvatinib, a multitarget tyrosine kinase inhibitor (TKI), increases the incidence of severe hypertension and thus the incidence of cardiovascular complications. Inhibition of ferroptosis, a newly recognized type of cell death, alleviates endothelial dysfunction. Here, we report that lenvatinib-induced hypertension is associated with ferroptosis of endothelial cells. RNA sequencing (RNA-seq) showed that lenvatinib led to ferroptosis of endothelial cells and that administration of mouse with ferrostatin-1 (Fer-1), a specific ferroptosis inhibitor, dramatically ameliorated lenvatinib-induced hypertension and reversed lenvatinib-induced impairment of endothelium-dependent relaxation (EDR). Furthermore, lenvatinib significantly reduced glutathione peroxidase 4 (GPX4) expressions in the mouse aorta and human umbilical vein endothelial cells (HUVECs) and increased lipid peroxidation, lactate dehydrogenase (LDH) release, and malondialdehyde (MDA) levels in HUVECs. Immunofluorescence and Western blotting showed that lenvatinib significantly reduced Yes-associated protein (YAP) nuclear translocation but not cytoplasmic YAP expression in HUVECs. The data, generated from both in vivo and in vitro, showed that lenvatinib reduced total YAP (t-YAP) expression and increased the phosphorylation of YAP at both Ser127 and Ser397, without affecting YAP mRNA levels in HUVECs. XMU-MP-1 mediated YAP activation or YAP overexpression effectively attenuated the lenvatinib-induced decrease in GPX4 expression and increases in LDH release and MDA levels. In addition, overexpression of YAP in HUVECs ameliorated lenvatinib-induced decrease in the mRNA and protein levels of spermidine/spermine N (1)-acetyltransferase-1 (SAT1), heme oxygenase-1 (HO-1), and ferritin heavy chain 1 (FTH1). Taken together, our data suggest that lenvatinib-induced inhibition of YAP led to ferroptosis of endothelial cells and subsequently resulted in vascular dysfunction and hypertension.
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Ferroptose , Hipertensão , Humanos , Camundongos , Animais , Pressão Sanguínea , Células Endoteliais da Veia Umbilical Humana , RNA MensageiroRESUMO
With the increasing reliance on intensive arable agriculture, analysis of the problems associated with continuous cropping has become a global research focus. Here, high-throughput sequencing and nontargeted metabolomics were used to evaluate the responses of soil microbial community structure and soil metabolic function to continuous cucumber cultivation (from 1 to 18 years of continuous cultivation) in greenhouses. Continuous cucumber cropping resulted in increased soil nutrient concentrations, but decreased concentrations of available nutrients. The abundance of several bacterial genera associated with nutrient cycling, such as Bacillus and Sphingomonas, was reduced by continuous cucumber cultivation. The abundance of several beneficial fungal genera, including pathogen antagonists (e.g. Chaetomium, Mortierella, Aspergillus, and Penicillium), were found to gradually decrease in response to the increased duration of continuous cropping. 3-amino-2-naphthoic acid and L-valine increased initially and then decreased as the cropping continued, which were related to fatty acid metabolism and amino acid biosynthesis. We also confirmed a close association between microbial community structure and soil metabolites. This study linked the changes in microbial community structure and metabolites in the rhizosphere soil and provided new insights into soil-microbial interactions in continuous cucumber culture systems.
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Cucumis sativus , Microbiota , Cucumis sativus/microbiologia , Solo/química , Microbiologia do Solo , RizosferaRESUMO
Smartphones are not only multifunctional tools but also users' personal extensions and identity symbols, as they are constantly with users and highly visible to the public while in use. Due to this public property as well as the close bond between smartphones and users, they are frequently used for personal identity expression besides functional purposes. The current study conceptualizes such behavior as symbolic use and aims to understand it. Anchoring on the attachment theory, mobile identity is postulated as an important antecedent of symbolic use. Mobile identity in turn is formed by mobile symbolism and mobile design esthetics. The research model was tested by a hybrid of both online and offline survey with 271 valid responses. SEM analysis was used to test the research model and SPSS was used for descriptive statistics. The results confirmed the role of mobile identity in affecting smartphone symbolic use. Additionally, individual materialism was confirmed as a moderator using hierarchical analysis. By defining and explaining smartphone symbolic use, this study clarifies the unique characteristics of the smartphone usage context as compared to non-portable technologies, thereby enriching the mobile usage literature and the application of attachment theory. It also defines the boundary condition of attachment formation by studying the contingent role of individual characteristics.
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Aplicativos Móveis , Smartphone , Inquéritos e QuestionáriosRESUMO
Background: Rotator cuff tear has become one of the diseases affecting people's living quality. Conventional anchor materials such as titanium alloy and poly-lactic acid can lead to postoperative complications like bone defects and aseptic inflammation. Magnesium (Mg)-based implants are biodegradable and biocompatible, with strong potential to be applied in orthopaedics. Methods: In this study, we developed a high-purity (HP) Mg suture anchor and studied its mechanical properties and degradation behavior in vitro. Furthermore, we described the use of high-purity Mg to prepare suture anchor for the rotator cuff repair in sheep. Results: The in vitro tests showed that HP Mg suture anchor possess proper degradation behavior and appropriate mechanical property. Animal experiment indicated that HP Mg suture anchor provided reliable anchoring function in 12 weeks and showed no toxic effect on animal organs. Conclusion: In summary, the HP Mg anchor presented in this study had favorable mechanical property and biosecurity.The translational potential of this article: The translational potential of this article is to use high-purity Mg to develop a degradable suture anchor and verify the feasibility of the application in animal model. This study provides a basis for further research on the clinical application of biodegradable high-purity Mg suture anchor.
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The peptidoglycan (PG) layer of bacterial cells is essential for maintaining the cell shape and survival of cells; therefore, the synthesis of PG needs to be spatiotemporally controlled. While it is well established that PG synthesis is mediated posttranslationally through interactions between PG synthases and their cognate partners, much less is known about the transcriptional regulation of genes encoding these synthases. Based on a previous finding that the Gram-negative bacterium Shewanella oneidensis lacking the prominent PG synthase exhibits impaired cell wall integrity, we performed genetic selections to isolate the suppressors. We discovered that disrupting the sspA gene encoding stringent starvation protein A (SspA) is sufficient to suppress compromised PG. SspA serves as a transcriptional repressor that regulates the expression of the two types of PG synthases, class A penicillin-binding proteins and SEDS/bPBP protein complexes. SspA is an RNA polymerase-associated protein, and its regulation involves interactions with the σ70 -RNAP complex and an antagonistic effect of H-NS, a global nucleoid-associated protein. We also present evidence that the regulation of PG synthases by SspA is conserved in Escherichia coli, adding a new dimension to the current understanding of PG synthesis and its regulation.
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Proteínas de Escherichia coli , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Peptidoglicano/metabolismo , Proteína Estafilocócica A/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Parede Celular/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismoRESUMO
Background: Previous studies have demonstrated that activated endothelial epithelial sodium channel (EnNaC) impairs vasodilatation, which contributes to salt-sensitive hypertension. Here, we investigate whether mesenteric artery (MA) EnNaC is involved in cold exposure-induced hypertension (CIH) and identify the underlying mechanisms in SD rats. Methods: One group of rats was housed at room temperature and served as control. Three groups of rats were kept in a 4°C cold incubator for 10 h/day; among which two groups were administrated with either benzamil (EnNaC blocker) or eplerenone (mineralocorticoid receptor antagonist, MR). Blood pressure (BP), vasodilatation, and endothelial function were measured with tail-cuff plethysmography, isometric myograph, and Total Nitric Oxide (NO) Assay kit, respectively. A cell-attached patch-clamp technique, in split-open MA, was used to determine the role of EnNaC in CIH rats. Furthermore, the plasma aldosterone levels were detected using an ELISA kit; and Western blot analysis was used to examine the relative expression levels of Sgk1 and Nedd4-2 proteins in the MA of SD rats. Results: We demonstrated that cold exposure increased BP, impaired vasodilatation, and caused endothelial dysfunction in rats. The activity of EnNaC significantly increased, concomitant with an increased level of plasma aldosterone and activation of Sgk1/Nedd4-2 signaling. Importantly, CIH was inhibited by either eplerenone or benzamil. It appeared that cold-induced decrease in NO production and impairment of endothelium-dependent relaxation (EDR) were significantly ameliorated by either eplerenone or benzamil in MA of CIH rats. Moreover, treatment of MAs with aldosterone resulted in an activation of EnNaC, a reduction of NO, and an impairment of EDR, which were significantly inhibited by either eplerenone or GSK650394 (Sgk1 inhibitor) or benzamil. Conclusion: Activation of EnNaC contributes to CIH; we suggest that pharmacological inhibition of the MR/Sgk1/Nedd4-2/EnNaC axis may be a potential therapeutic strategy for CIH.
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There is an urgent need to develop novel antibiotics since antibiotic resistance is an increasingly serious threat to global public health. Whole-cell biosensors are one of the promising strategies for new antibiotic discovery. The peptidoglycan (PG) of the bacterial cell wall is one of the most important targets for antibiotics. However, the biosensors for the detection of PG-targeting antibiotics in Gram-negative bacteria have not been developed, mainly because of the lack of the regulatory systems that sense and respond to PG stress. Recently, we identified a novel two-component signal transduction system (PghKR) that is responsible for sensing and responding to PG damage in the Gram-negative bacterium Shewanella oneidensis. Based on this system, we developed biosensors for the detection of PG-targeting antibiotics. Using ampicillin as an inducer for PG stress and the bacterial luciferase LuxCDABE as the reporter, we found that the PghKR biosensors are specific to antibiotics targeting PG synthesis, including ß-lactams, vancomycin, and d-cycloserine. Deletion of genes encoding PG permease AmpG and ß-lactamase BlaA improves the sensitivity of the biosensors substantially. The PghKR biosensor in the background of ΔblaA is also functional on agar plates, providing a simple method for screening bacteria that produce PG-targeting antibiotics. IMPORTANCE The growing problem of antibiotic resistance in Gram-negative bacteria urgently needs new strategies so that researchers can develop novel antibiotics. Microbial whole-cell biosensors are capable of sensing various stimuli with a quantifiable output and show tremendous potential for the discovery of novel antibiotics. As the Achilles' heel of bacteria, the synthesis of the peptidoglycan (PG) is targeted by many antibiotics. However, the regulatory systems that sense and respond to PG-targeting stress in Gram-negative bacteria are reported rarely, restricting the development of biosensors for the detection of PG-targeting antibiotics. In this study, we developed a highly sensitive and specific biosensor based on a novel two-component system in the Gram-negative bacterium Shewanella oneidensis that is responsible for the sensing and responding to PG stress. Our biosensors have great potential for discovering novel antibiotics and determining the mode of action of antibiotics.
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Técnicas Biossensoriais , Shewanella , Ágar , Ampicilina , Antibacterianos/farmacologia , Parede Celular/metabolismo , Ciclosserina , Bactérias Gram-Negativas/genética , Bactérias Gram-Negativas/metabolismo , Luciferases Bacterianas , Proteínas de Membrana Transportadoras , Peptidoglicano/metabolismo , Shewanella/genética , Shewanella/metabolismo , Vancomicina , beta-Lactamases/genética , beta-Lactamas/farmacologiaRESUMO
Traditional methods of quantifying epidemic spread are based on surveillance data. The most widely used surveillance data are normally incidence data from case reports and hospital records, which are normally susceptible to human error, and sometimes, they even can be seriously error-prone and incomplete when collected during a destructive epidemic. In this manuscript, we introduce a new method to study the spread of infectious disease. We gave an example of how to use this method to predict the virus spreading using the HIV gene sequences data of China. First, we applied Bayesian inference to gene sequences of two main subtypes of the HIV virus to infer the effective reproduction number (GRe(t)) to trace the history of HIV transmission. Second, a dynamic model was established to forecast the spread of HIV medication resistance in the future and also obtain its effective reproduction number (MRe(t)). Through fitting the two effective reproduction numbers obtained from the two separate ways above, some crucial parameters for the dynamic model were obtained. Simply raising the treatment rate has no impact on lowering the infection rate, according to the dynamics model research, but would instead increase the rate of medication resistance. The negative relationship between the prevalence of HIV and the survivorship of infected individuals following treatment may be to blame for this. Reducing the MSM population's number of sexual partners is a more efficient strategy to reduce transmission per the sensitivity analysis.