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OBJECTIVE: To evaluate the efficacy of urokinase (UK) treatment for tuberculous pleural effusion (TPE). METHODS: We searched Chinese biomedical literature database, WanFang data, CNKI, PubMed, EMbase, Web of Science and The Cochrane Library for the randomized controlled trials (RCTs) of urokinase treatment for tuberculous pleurisy from January 2000 to February 2023. Pleural tuberculosis, urokinase and randomized controlled trial were used as keywords. The eligible studies were meta-analyzed by using Revman 5.4.1: risk of bias was assessed, mean difference (MD) and 95% CI were used for continuous variables, pooled studies were conducted using random-effects or fixed-effects models, forest plots were drawn to analyze efficacy, and funnel plots were drawn to discuss publication bias. RESULTS: Twenty-nine RCTs were included. The meta-analyzed results showed that, on the basis of routine anti-tuberculosis, comparison between the treatment group treated with urokinase and the control group treated with antituberculosis alone, the time of pleural effusion absorption [MD-5.82, 95%CI (- 7.77, - 3.87); P<0.00001] and the residual pleural thickness [MD-1.31, 95%CI (- 1.70, - 0.91); P<0.00001], pleural effusion drainage volume [MD 822.81, 95%CI (666.46,977.96); P<0.00001], FVC%pred [MD 7.95, 95%CI (4.51,11.40); P<0.00001], FEV1%pred [MD 12.67, 95%CI (10.09,15.24); P<0.00001] were significantly different. CONCLUSION: The clinical effect of urokinase is better than that of antituberculous therapy alone: it can increase total pleural effusion, decrease residual pleural thickness, improve the pulmonary function, and shorten the time of pleural effusion absorption.
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Derrame Pleural , Tuberculose Pleural , Ativador de Plasminogênio Tipo Uroquinase , Humanos , Tuberculose Pleural/tratamento farmacológico , Ativador de Plasminogênio Tipo Uroquinase/uso terapêutico , Derrame Pleural/tratamento farmacológico , Antituberculosos/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do TratamentoRESUMO
Antineoplastic agents that target tubulin have shown efficacy as chemotherapeutic drugs, yet they are often constrained by multidrug resistance (MDR) and unwanted side effects. A multi-targeted strategy demonstrates great potency in reducing toxicity and enhancing efficacy and provides an alternative way for attenuating MDR. In this study, a series of dual-targeted anti-cancer agents based on indole-chalcone derivatives and the camptothecin (CPT) scaffold were synthesized. Among them, 14-1 demonstrated superior anti-proliferative activity than its precursor 13-1, CPT or their physical mixtures against tested cancer cells, including multidrug-resistant variants, while exhibited moderate cytotoxicity toward human normal cells. Mechanistic studies revealed that 14-1 acted as a glutathione-responsive prodrug, inducing apoptosis by substantially enhancing intracellular uptake of CPT, inhibiting tubulin polymerization, increasing the accumulation of intracellular reactive oxygen species, and initiating a mitochondrion-dependent apoptotic pathway. Moreover, 14-1 notably induced autophagy and suppressed topoisomerase I activity to further promote apoptosis. Importantly, 14-1 displayed potent inhibitory effect on tumor growth in paclitaxel (PTX)-resistant colorectal cancer (HCT-116/PTX) xenograft models without inducing obvious toxicity compared with CPT- or combo-treated group. These results suggest that 14-1 holds promise as a novel candidate for anti-cancer therapy, particularly in PTX-resistant cancers.
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Antineoplásicos , Chalconas , Neoplasias do Colo , Pró-Fármacos , Humanos , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Camptotecina/farmacologia , Linhagem Celular Tumoral , Chalconas/farmacologia , Neoplasias do Colo/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos , Glutationa , Paclitaxel/farmacologia , Pró-Fármacos/farmacologia , Tubulina (Proteína)/farmacologia , Autofagia/efeitos dos fármacosRESUMO
BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) often require hospital readmission because of exacerbation of their condition. These frequent exacerbations reduce quality of life, work performance, and emotional health. However, few studies have investigated the risk factors for readmission and readmission rates in Asian patients with COPD. We conducted a systematic review to identify and understand the major risk factors for readmission in patients with COPD in Asia and the readmission rate. METHOD: We searched PubMed, MEDLINE, Embase, China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform, and China Biomedical Literature Database from database inception to September 2023 to identify studies on the readmission rate and risk factors for COPD in Asian patients. Chinese search terms included "COPD," "chronic obstructive pulmonary disease," "risk factors," "recurrence," "readmission," and "acute exacerbation." English search terms included "chronic obstructive pulmonary disease," "COPD," "lung emphysema," "hospital admission," "patient readmission," and "readmission." We extracted first author, publication year, research area, sample size, sex, risk factors, and readmission rates. The included studies' quality was evaluated using the Agency of Healthcare Research and Quality. Meta-synthesis was conducted on readmission rates and risk factors for readmission. Subgroups were formed by age, research area, sample size, and research type, and meta-regression analysis was conducted on the 30-day, 90-day, and 365-day readmission rates of patients to determine the source of heterogeneity. Finally, the results' robustness was evaluated using sensitivity analysis. Begg and Egger tests were used to evaluate publication bias. RESULTS: Meta-analysis of 44 studies, with 169,255 participants, indicated that risk factors for COPD readmission in Asia included: history of multiple hospital admissions, ≥ 3 comorbidities, male sex, ratio of eosinophils percentage ≥ 2%, body mass index < 18.5, smoking history, pulmonary heart disease comorbidity, COPD assessment test score > 20, nutritional disorder, Neutrophil-to-Lymphocyte ratio > 7, and FEV1 < 50. The 30-, 90-, and 365-day readmission rates of patients were 19%, 31%, and 42%, respectively. CONCLUSIONS: Patients with COPD in Asia generally have high readmission rates and different risk factors. To reduce healthcare, economic, and social burdens, interventions should address major risk factors, early prevention, and screening.
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Readmissão do Paciente , Doença Pulmonar Obstrutiva Crônica , Humanos , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Doença Pulmonar Obstrutiva Crônica/terapia , Readmissão do Paciente/estatística & dados numéricos , Fatores de Risco , Ásia/epidemiologiaRESUMO
Pseudorabies virus (PRV) belongs to the alpha herpesvirus family and is responsible for Aujeszky's disease in pigs. Similar to other alpha herpesviruses, PRV establishes a lifelong latent infection in trigeminal ganglion. These latently infected pigs serve as a reservoir for recurrent infections when reactivation is triggered, making the eradication of PRV a challenging task. However, the molecular mechanism underlying PRV latency and reactivation in neurons is still poorly understood due to limitations in the in vitro model. To establish a pseudorabies virus latency and reactivation model in primary neuron cultures, we isolated dorsal root ganglion (DRG) from newborn Kunming mice using a method named epineurium-pulling for DRG collection (EPDC) and cultured primary neurons in vitro. A dual-colour recombinant PRV BAC mRuby-VP16 was constructed and 0.5 multiplicity of infection (MOI) was found as an appropriate dose in the presence of aciclovir to establish latency. Reactivation was induced using UV-inactivated herpesviruses or a series of chemical inhibitors. Interestingly, we found that not only UV-PRV, but also UV-HSV-1 and UV-BHoV-5 were able to induce rapid PRV reactivation. The efficiency of reactivation for LY294002, forskolin, etoposide, dexamethasone, and acetylcholine was found to be dependent on their concentration. In conclusion, we developed a valuable model of PRV latency and reactivation, which provides a basis for future mechanism research.
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Herpesvirus Suídeo 1 , Pseudorraiva , Camundongos , Animais , Suínos , Herpesvirus Suídeo 1/fisiologia , Gânglios Espinais , Latência Viral , Ativação ViralRESUMO
In this study, we investigated the mechanism of hepatitis B virus (HBV)-enveloped particle release. Specifically, we used preS1 as a bait protein to screen host proteins using mass spectroscopy, with the results of immunofluorescence, western blot, co-immunoprecipitation, isothermal titration calorimetry, and pull-down assays identifying glucose-regulated protein (GRP)78 as a specific target for preS1 binding. We employed transcriptome sequencing, enzyme-linked immunosorbent assays, and particle gel assays to investigate the mechanism of GRP78-mediated positive regulation of HBV-enveloped particle release. Additionally, we performed phage-display, surface plasmon resonance, and molecular-docking assays to assess peptides inhibiting enveloped-particle release. We found that HBV upregulated GRP78 expression in liver cell lines and the serum of patients with chronic hepatitis B. Furthermore, GRP78 promoted the release of HBV-enveloped particles in vitro and in vivo within an HBV transgenic mouse model. Moreover, we identified interactions of preS1 peptides with GRP78 via hydrogen bonding and hydrophobic interactions, which effectively inhibited its interaction with HBV-enveloped particles and their subsequent release. These findings provide novel insights regarding HBV virion release, and demonstrated that GRP78 interacted with preS1 to positively regulate the release of HBV-enveloped particles, suggesting GRP78 as a potential therapeutic target for inhibiting HBV infection.
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Chaperona BiP do Retículo Endoplasmático , Hepatite B , Animais , Camundongos , Vírus da Hepatite B/fisiologia , Proteínas , Peptídeos , Vírion , Antígenos de Superfície da Hepatite B/químicaRESUMO
According to the latest epidemiological investigation, lung adenocarcinoma (LUAD) is one of the most fatal cancer among both men and women. Despite continuous advancements in treatment approaches in recent years, the prognosis for LUAD remains relatively poor. Given the crucial role of the solute carrier (SLC) family in maintaining cellular energy metabolism stability, we conducted a comprehensive analysis of the association between SLC genes and LUAD prognosis. In the present study, we identified 71 genes among the SLC family members, of which 32 were downregulated and 39 were upregulated in LUAD samples. Based on these differentially expressed genes, a prognostic risk scoring model was established that was composed of five genes (SLC16A7, SLC16A4, SLC16A3, SLC12A8, and SLC25A15) and clinical characteristics; this model could effectively predict the survival and prognosis of patients in the cohort. Notably, SLC2A1, SLC25A29, and SLC27A4 were identified as key genes associated with survival and tumor stage. Further analysis revealed that SLC25A29 was underexpressed in LUAD tissue and regulated the phenotype of endothelial cells. Endothelial cell proliferation and migration increased and apoptosis decreased with a decrease in SLC25A29 expression. Investigation of the upstream regulatory mechanisms of SLC25A29 revealed that SLC25A29 expression gradually decreased as the lactate concentration increased. This phenomenon suggested that the expression of SLC25A29 may be related to lactylation modification. ChIP-qPCR experiments confirmed the critical regulatory role played by H3K14la and H3K18la modifications in the promoter region of SLC25A29. In conclusion, this study confirmed the role of SLC family genes in LUAD prognosis and revealed the role of SLC25A29 in regulating endothelial cell phenotypes. These study results provided important clues to further understand LUAD pathogenesis and develop appropriate therapeutic strategies.
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Two metal sulfate-oxalates, (Hgly)2·Zn(SO4)(C2O4) (1) and Hgly·In(SO4)(C2O4)(gly) (2), were prepared under solvent-free conditions, where gly = glycine. They have similar layered structures despite the fact that aliovalent metal ions are used as structural nodes. Notably, glycine molecules play dual roles as a protonated cation and a zwitterionic ligand in compound 2. The two compounds display moderate second-harmonic-generation (SHG) responses, confirming their noncentrosymmetric structures. Theoretical calculations were performed to reveal the origin of their SHG responses.
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OBJECTIVES: The purpose of this study was to clarify the relationship between obstructive sleep apnea (OSA) and oxidative stress markers in blood. METHODS: We conducted a systematic literature search on databases including Pubmed and Embase for studies reporting circulating oxidative stress markers in patients with OSA and controls that were published between 1988 and June 2019. Standardized mean differences (SMDs) and 95% confidence intervals (95%CI) were calculated. RESULTS: Of the 2226 articles initially retrieved, 52 were included in our meta-analysis, covering a total of 12 oxidative stress markers. The concentrations of malondialdehyde (SMD = 1.18; 95%CI: 0.87, 1.49; p < 0.001), thiobarbituric acid reactive substances (SMD = 1.82; 95%CI: 0.79, 2.86; p = 0.001), advance oxidative protein products (SMD = 0.68; 95%CI: 0.14, 1.23; p = 0.014), total oxidant capacity (SMD = 1.32; 95%CI: 0.33, 2.31; p = 0.009), and asymmetric dimethylarginine (SMD = 0.32; 95%CI: 0.16, 0.47; p < 0.001) in the blood of patients with OSA were higher than those of the control group, whereas the concentrations of thiols (SMD = - 0.37; 95%CI: - 0.60, - 0.15; p = 0.001) and nitric oxide (SMD = - 2.61; 95%CI: - 4.02, - 1.21; p < 0.001) were lower than those of the control group. CONCLUSIONS: The oxidative stress markers in the blood of patients with OSA were aberrant, indicating an imbalanced state of oxidation and antioxidation in OSA.
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Apneia Obstrutiva do Sono , Humanos , Apneia Obstrutiva do Sono/diagnóstico , Biomarcadores , Estresse Oxidativo , Malondialdeído , Óxido NítricoRESUMO
PURPOSE: Chronic intermittent hypoxia (CIH) plays a key role in the complications of obstructive sleep apnea (OSA), which is strongly associated with retinal and optic nerve diseases. Additionally, the brain-derived neurotrophic factor (BDNF)/tropomyosin receptor kinase B (TrkB) signaling pathway plays an important protective role in neuronal injury. In the present study, we investigated the role of 7,8-dihydroxyflavone (7,8-DHF) in regulating CIH-induced injury in mice retinas and rat primary retinal ganglion cells (RGCs). METHODS: C57BL/6 mice and in vitro primary RGCs were exposed to CIH or normoxia and treated with or without 7,8-DHF. The mice eyeballs or cultured cells were then taken for histochemistry, immunofluorescence or biochemistry, and the protein expression of the BDNF/TrkB signaling pathway analysis. RESULTS: Our results showed that CIH induced oxidative stress (OS) in in vivo and in vitro models and inhibited the conversion of BDNF precursor (pro-BDNF) to a mature form of BDNF, which increased neuronal cell apoptosis. 7,8-DHF reduced the production of reactive oxygen species (ROS) caused by CIH and effectively activated TrkB signals and downstream protein kinase B (Akt) and extracellular signal-regulated kinase (Erk) survival signaling pathways, which upregulated the expression of mature BDNF. ANA-12 (a TrkB specific inhibitor) blocked the protective effect of 7,8-DHF. CONCLUSION: In short, the activation of the BDNF/TrkB signaling pathway alleviated CIH-induced oxidative stress damage of the optic nerve and retinal ganglion cells. 7,8-DHF may serve as a promising agent for OSA related neuropathy.
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Fator Neurotrófico Derivado do Encéfalo/efeitos dos fármacos , Fator Neurotrófico Derivado do Encéfalo/fisiologia , Hipóxia Celular/efeitos dos fármacos , Flavonas/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Receptor trkB/efeitos dos fármacos , Receptor trkB/fisiologia , Células Ganglionares da Retina/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
BACKGROUND: Pharmacy intravenous admixture service (PIVAS) center has emerged as an important department of hospital as it can improve occupational protection and ensure the safety and effectiveness of intravenous infusions. However, medication errors were considered to be a significant challenge in PIVAS, so information-intelligence technologies were introduced to optimize the management of PIVAS. Our article summarized the application of information-intelligence technologies in PIVAS of a large third-class A hospital in China, and provided an example for PIVAS in other hospitals at home and abroad. METHODS: Prescription-reviewing rules containing intravenous medications and infusion solution guideline were recorded in the database of prescription-cheking system. Drugs information were recorded in the PIVAS management system with special identification and warning labels to reduce intravenous infusion errors. Automatic labeling device was used to label the infusion bags, and the quality control program database of intelligent compounding robot for cytotoxic drugs was established ingeniously. Automatic sorting devices were applied for the third batch of finished infusion admixtures, and intelligent logistics robots were used to transport the infusion to the ward. RESULTS: After establishing and implementing of prescription-reviewing rules in the prescription-cheking system database, the number of prescriptions checked by pharmacists increased from 18 to 43 per minute. The success rate of intervention with irrational medical orders increased from 85.89% to 99.06% (P < 0.05). By introducing various intelligent devices, automatic labeling significantly enhanced work efficiency and reduced the error rate (P < 0.001). Furthermore, the use of intelligent intravenous compounding robots significantly reduced the risk of errors (P < 0.001). CONCLUSIONS: The application of information-intelligence technologies in PIVAS can improve work efficiency and reduce error risk. However, some intelligent devices have failed to achieve the expected effect in practical use, and further improvements are needed to meet the demands of PIVAS in the future.
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Serviço de Farmácia Hospitalar , Farmácia , Composição de Medicamentos , Hospitais , Humanos , InteligênciaRESUMO
Lifetime optimization is one of the key issues among the many challenges of wireless sensor networks. The introduction of a small number of high-performance relay nodes can effectively improve the quality of the network services. However, how to deploy these nodes reasonably to fully enhance the network lifetime becomes a very difficult problem. In this study, a modified and enhanced Artificial Bee Colony is proposed to maximize the lifetime of a two-tiered wireless sensor network by optimal deployment of relay nodes. First, the dimension of the problem is introduced into the candidate search equation and the local search is adjusted according to the fitness of the problem and number of iterations, which helps to balance the exploration and exploitation ability of the algorithm. Second, in order to prevent the algorithm from falling into local convergence, a dynamic search balance strategy is proposed instead of the scout bee phase in the original Artificial Bee Colony. Then, a feasible solution formation method is proposed to ensure that the relay nodes can form the upper-layer backbone of the network. Finally, we employ this algorithm on a test dataset obtained from the literature. The simulation results show that the proposed algorithm for two-tiered wireless sensor network lifetime optimization can obtain higher and stable average network lifetime and more reasonable relay node deployment compared to other classical and state-of-the-art algorithms, verifying the competitive performance of the proposed algorithm.
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Algoritmos , Simulação por ComputadorRESUMO
Porcine epidemic diarrhea virus (PEDV) has become increasingly problematic around the world, not only for its hazards to livestock but also due to the possibility that it is a zoonotic disease. Although vaccine therapy has made some progress toward PEDV control, additional effective therapeutic strategies against PEDV are needed, such as the development of chemotherapeutic agents. The aim of this work was to identify novel anti-PEDV agents by designing and synthesizing a series of phenanthridine derivatives. Among them, three compounds (compounds 1, 2, and 4) were identified as potent anti-PEDV agents exhibiting suppression of host cell heat shock cognate 70 (Hsc70) expression. Mechanism studies revealed that host Hsc70 is involved in the replication of PEDV, and its expression can be suppressed by destabilization of the mRNA, resulting in inhibition of PEDV replication. Activity against PEDV in vivo in PEDV-infected piglets suggested that phenanthridine derivatives are the first host-acting potential anti-PEDV agents.
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Antivirais/farmacologia , Proteínas de Choque Térmico HSC70/metabolismo , Fenantridinas/farmacologia , Vírus da Diarreia Epidêmica Suína/efeitos dos fármacos , Animais , Antivirais/síntese química , Linhagem Celular , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/veterinária , Desenho de Fármacos , Estrutura Molecular , Fenantridinas/síntese química , SuínosRESUMO
A flexible strain sensor which integrates both pressure sensing and tension sensing functions is demonstrated with an active layer comprising of polydimethy-lsiloxane (PDMS) elastomer, liquid crystal (LC), and multi-walled carbon nanotubes (MWCNTs). The introduction of LC improves the agglomeration of MWCNTs in PDMS and decreases Young's modulus of flexible resistive sensors. The tension/pressure integrated resistive sensor not only shows a broad tensile sensing range of 140% strain but also shows a good sensitivity of the gauge factor, 40, with tensile force. Besides, the tension/pressure integrated resistive sensor also shows good linearity and sensitivity under pressure. The resistance of the pressure sensor increases as the applied pressure increases because of the decrease in the cross-sectional area of the path. The sensor also shows good hydrophobic properties which may help it to work under complex environment. The tension/pressure integrated sensor shows great promising applications in electronic skins and wearable devices.
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Cristais Líquidos , Nanotubos de Carbono , Dispositivos Eletrônicos Vestíveis , Dimetilpolisiloxanos , Módulo de ElasticidadeRESUMO
Emerging studies have shown that the aberrant expression and function of long non-coding RNAs (lncRNAs) are involved in carcinogenesis and the development of various cancers. The long noncoding RNA JPX (lncRNA JPX) on the X chromosome is an activator of X-inactive-specific transcript (XIST) and is a molecular switch for X-chromosome inactivation. However, the exact mechanism by which JPX acts in non-small-cell lung cancer (NSCLC) is not well studied. Here, through integrating clinical data and a series of functional experiments, we found that lncRNA JPX expression is significantly upregulated in NSCLC tissues compared with that in paired adjacent normal tissues from two independent datasets and significantly associated with a poor survival and other malignant phenotypes (tumor stage, tumor volume) of NSCLC. Furthermore, we elucidated that JPX functions as an oncogene in NSCLC-promoting cell proliferation and cell migration by affecting cell-cycle progression. Mechanistically, JPX upregulates cyclin D2 (CCND2) expression in a competing endogenous RNA mechanism by interacting with miR-145-5p, thus provoking the development and progression of NSCLC. These findings reveal the mechanism of X-chromosome lncRNA JPX and its core regulatory circuitry JPX/miR-145-5p/CCND2 in the development and progression of NSCLC, which bring us closer to an understanding of the molecular drivers of NSCLC.
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Biomarcadores Tumorais/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Ciclina D2/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/patologia , MicroRNAs/genética , RNA Longo não Codificante/genética , Animais , Apoptose , Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Ciclo Celular , Movimento Celular , Proliferação de Células , Ciclina D2/genética , Progressão da Doença , Feminino , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Prognóstico , Taxa de Sobrevida , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: Hepatic steatosis that occasionally results in nonalcoholic steatohepatitis (NASH) is related to obstructive sleep apnea (OSA). Many studies have shown that autophagy exerts protective effects on liver damage caused by various diseases and melatonin exhibits hepatoprotective properties. However, the mechanisms of liver injury induced by chronic intermittent hypoxia (CIH) and the effect of melatonin on the regulation of liver injury remain unclear. PURPOSE: This study was aimed to evaluate the role of CIH in steatohepatitis progression and the regulatory function of melatonin on fatty liver sensitivity to CIH injury, mainly focusing on autophagy signaling. METHODS: A high-fat diet (FD)-induced obesity mouse model was subjected to intermittent hypoxia/normoxia events for approximately 8 h per day using an autophagy agonist, rapamycin, or an inhibitor, 3-methyladenine (3-MA), and SRT1720, a sirtuin 1 (SIRT1) activator, or sirtinol, a SIRT1 inhibitor, with or without melatonin for a total of six successive weeks, followed by assessment of expression of autophagy-related genes and activity of serum aminotransferase as well as histological evaluation of tissue morphology. RESULTS: Neither FD nor CIH alone causes significant liver injury; however, the combination yielded higher serum aminotransferase activities and more severe histological changes, accompanied by a decrease in autophagy activity. Melatonin markedly inhibited FD/CIH-stimulated liver injury by enhancing autophagy. In contrast, SIRT1 inhibition resulted in a decrease in the expression of melatonin-induced autophagy-related genes as well as diminished its protective effects on FD/CIH-induced liver injury. CONCLUSION: These results suggest that melatonin could ameliorate FD/CIH-induced hepatocellular damage by activating SIRT1-mediated autophagy signaling.
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Autofagia/efeitos dos fármacos , Hipóxia/fisiopatologia , Melatonina/farmacologia , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Animais , Cardiotônicos/farmacologia , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Feminino , Hipóxia/metabolismo , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/metabolismo , Estresse Oxidativo/efeitos dos fármacosRESUMO
Menaquinone-7 (MK-7) plays an important role in blood clotting, cardiovascular disease and anti-osteoporosis, and has been wildly used in the food additives and pharmaceutical industries. The aim of this study was to investigate the mechanism of menaquinone-7 biosynthesis in response to different oxygen supplies in Bacillus natto. The differences of fermentation performance, intracellular metabolites, oxidative stress reaction and enzyme activities of Bacillus natto R127 were analyzed under different KLa. Glycerol consumption rate and MK-7 yield at 24.76 min- 1 was 2.1 and 7.02 times of that at 18.23 min- 1. Oxidative stress analysis showed the cell generated more active oxygen and possessed higher antioxidant capacity at high oxygen supply condition. Meanwhile, high pyruvate kinase and high cytochrome c oxidase activities were also observed at 24.76 min- 1. Furthermore, comparative metabolomics analyses concluded series of biomarkers for high MK-7 biosynthesis and cell rapid growth. Besides, several metabolic responses including low glyceraldehyde-3-phosphate accumulation, low flux from pyruvate to lactic acid, high active TCA pathway, were also found to be associated with high MK-7 accumulation at high oxygen supply conditions. These findings provided the information for better understanding of oxygen effect on MK-7 biosynthesis and lay a foundation for further improvement of MK-7 production as well.
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Bacillus subtilis/metabolismo , Glicerol/metabolismo , Estresse Oxidativo , Consumo de Oxigênio , Oxigênio/metabolismo , Vitamina K 2/análogos & derivados , Vitamina K 2/metabolismoRESUMO
Human GRP78 has been shown to promote cancer progression and is regarded as a novel target for anticancer drugs. However, generation of recombinant full-length GRP78 remains challenging. This report demonstrates that E. coli autoinduction is an excellent method for the preparation of active recombinant GRP78 protein. The final yield was approximately 50 mg/liter of autoinduction culture. Gel-filtration experiments confirmed that the chaperone is a monomer. The purified human GRP78 catalyzed the conversion of ATP to ADP without requiring metal ions as cofactors. Three mutants, T38A, T229A, and S300A, exhibited much lower activity than wild-type GRP78, indicating that the active sites of the ATPase are located at the negatively charged cavity. Three mutants in the negatively charged cavity region dramatically reduced GRP78 activity, further confirming the region as the site of ATPase activity.
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Adenosina Trifosfatases/biossíntese , Adenosina Trifosfatases/química , Expressão Gênica , Proteínas de Choque Térmico/biossíntese , Proteínas de Choque Térmico/química , Mutação de Sentido Incorreto , Adenosina Trifosfatases/genética , Substituição de Aminoácidos , Chaperona BiP do Retículo Endoplasmático , Proteínas de Choque Térmico/genética , Humanos , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/genéticaRESUMO
The obligate intracellular human pathogen Chlamydia trachomatis undergoes a complex developmental program involving transition between two forms: the infectious elementary body (EB), and the rapidly dividing reticulate body (RB). However, the regulators controlling this development have not been identified. To uncover potential regulators of transcription in C. trachomatis, we screened a C. trachomatis genomic library for sequences encoding proteins that interact with RNA polymerase (RNAP). We report the identification of one such protein, CT663, which interacts with the beta and sigma subunits of RNAP. Specifically, we show that CT663 interacts with the flap domain of the beta subunit (beta-flap) and conserved region 4 of the primary sigma subunit (sigma(66) in C. trachomatis). We find that CT663 inhibits sigma(66)-dependent (but not sigma(28)-dependent) transcription in vitro, and we present evidence that CT663 exerts this effect as a component of the RNAP holoenzyme. The analysis of C. trachomatis-infected cells reveals that CT663 begins to accumulate at the commencement of the RB-to-EB transition. Our findings suggest that CT663 functions as a negative regulator of sigma(66)-dependent transcription, facilitating a global change in gene expression. The strategy used here is generally applicable in cases where genetic tools are unavailable.
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Proteínas de Bactérias/metabolismo , Chlamydia trachomatis/enzimologia , RNA Polimerases Dirigidas por DNA/metabolismo , Regulação Bacteriana da Expressão Gênica , Fator sigma/metabolismo , Chlamydia trachomatis/metabolismo , Escherichia coli/enzimologiaRESUMO
Secretion of effector proteins into the eukaryotic host cell is required for Chlamydia trachomatis virulence. In the infection process, Scc1 and Scc4, two chaperones of the type III secretion (T3S) system, facilitate secretion of the important effector and plug protein, CopN, but little is known about the details of this event. Here we use biochemistry, mass spectrometry, nuclear magnetic resonance spectroscopy, and genetic analyses to characterize this trimolecular event. We find that Scc4 complexes with Scc1 and CopN in situ at the late developmental cycle of C. trachomatis. We show that Scc4 and Scc1 undergo dynamic interactions as part of the unique bacterial developmental cycle. Using alanine substitutions, we identify several amino acid residues in Scc4 that are critical for the Scc4-Scc1 interaction, which is required for forming the Scc4·Scc1·CopN ternary complex. These results, combined with our previous findings that Scc4 plays a role in transcription (Rao, X., Deighan, P., Hua, Z., Hu, X., Wang, J., Luo, M., Wang, J., Liang, Y., Zhong, G., Hochschild, A., and Shen, L. (2009) Genes Dev. 23, 1818-1829), reveal that the T3S process is linked to bacterial transcriptional events, all of which are mediated by Scc4 and its interacting proteins. A model describing how the T3S process may affect gene expression is proposed.