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Type VI secretion systems (T6SS) are bacterial macromolecular complexes that secrete effectors into target cells or the extracellular environment, leading to the demise of adjacent cells and providing a survival advantage. Although studies have shown that the T6SS in Pseudomonas aeruginosa is regulated by the Quorum Sensing system and second messenger c-di-GMP, the underlying molecular mechanism remains largely unknown. In this study, we discovered that the c-di-GMP-binding adaptor protein PA0012 has a repressive effect on the expression of the T6SS HSI-I genes in P. aeruginosa PAO1. To probe the mechanism by which PA0012 (renamed TssZ, Type Six Secretion System -associated PilZ protein) regulates the expression of HSI-I genes, we conducted yeast two-hybrid screening and identified HinK, a LasR-type transcriptional regulator, as the binding partner of TssZ. The protein-protein interaction between HinK and TssZ was confirmed through co-immunoprecipitation assays. Further analysis suggested that the HinK-TssZ interaction was weakened at high c-di-GMP concentrations, contrary to the current paradigm wherein c-di-GMP enhances the interaction between PilZ proteins and their partners. Electrophoretic mobility shift assays revealed that the non-c-di-GMP-binding mutant TssZR5A/R9A interacts directly with HinK and prevents it from binding to the promoter of the quorum-sensing regulator pqsR. The functional connection between TssZ and HinK is further supported by observations that TssZ and HinK impact the swarming motility, pyocyanin production, and T6SS-mediated bacterial killing activity of P. aeruginosa in a PqsR-dependent manner. Together, these results unveil a novel regulatory mechanism wherein TssZ functions as an inhibitor that interacts with HinK to control gene expression.
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Proteínas Bacterianas , Regulación Bacteriana de la Expresión Génica , Pseudomonas aeruginosa , Transcripción Genética , Sistemas de Secreción Tipo VI , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , GMP Cíclico/análogos & derivados , GMP Cíclico/metabolismo , Ensayo de Cambio de Movilidad Electroforética , Inmunoprecipitación , Mutación , Regiones Promotoras Genéticas , Unión Proteica , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/metabolismo , Piocianina/metabolismo , Percepción de Quorum , Sistemas de Mensajero Secundario , Técnicas del Sistema de Dos Híbridos , Sistemas de Secreción Tipo VI/genética , Sistemas de Secreción Tipo VI/metabolismoRESUMEN
Citrus canker, caused by the bacterium Xanthomonas citri subsp. citri (Xcc), seriously affects fruit quality and yield, leading to significant economic losses around the world. Understanding the mechanism of Xcc virulence is important for the effective control of Xcc infection. In this report, we investigate the role of a protein named HemK in the regulation of the virulence traits of Xcc. The hemK gene was deleted in the Xcc jx-6 background, and the ΔhemK mutant phenotypically displayed significantly decreased motility, biofilm formation, extracellular enzymes, and polysaccharides production, as well as increased sensitivity to oxidative stress and high temperatures. In accordance with the role of HemK in the regulation of a variety of virulence-associated phenotypes, the deletion of hemK resulted in reduced virulence on citrus plants as well as a compromised hypersensitive response on a non-host plant, Nicotiana benthamiana. These results indicated that HemK is required for the virulence of Xcc. To characterize the regulatory effect of hemK deletion on gene expression, RNA sequencing analysis was conducted using the wild-type Xcc jx-6 strain and its isogenic ΔhemK mutant strain, grown in XVM2 medium. Comparative transcriptome analysis of these two strains revealed that hemK deletion specifically changed the expression of several virulence-related genes associated with the bacterial secretion system, chemotaxis, and quorum sensing, and the expression of various genes related to nutrient utilization including amino acid metabolism, carbohydrate metabolism, and energy metabolism. In conclusion, our results indicate that HemK plays an essential role in virulence, the regulation of virulence factor synthesis, and the nutrient utilization of Xcc.
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Citrus , Xanthomonas , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Citrus/metabolismo , Metiltransferasas/metabolismo , Nutrientes , Enfermedades de las Plantas/microbiología , Virulencia/genéticaRESUMEN
The type VI secretion system (T6SS) is widely distributed in Gram-negative bacteria, whose function is known to translocate substrates to eukaryotic and prokaryotic target cells to cause host damage or as a weapon for interbacterial competition. Pseudomonas aeruginosa encodes three distinct T6SS clusters (H1-, H2-, and H3-T6SS). The H1-T6SS-dependent substrates have been identified and well characterized; however, only limited information is available for the H2- and H3-T6SSs since relatively fewer substrates for them have yet been established. Here, we obtained P. aeruginosa H2-T6SS-dependent secretomes and further characterized the H2-T6SS-dependent copper (Cu2+)-binding effector azurin (Azu). Our data showed that both azu and H2-T6SS were repressed by CueR and were induced by low concentrations of Cu2+. We also identified the Azu-interacting partner OprC, a Cu2+-specific TonB-dependent outer membrane transporter. Similar to H2-T6SS genes and azu, expression of oprC was directly regulated by CueR and was induced by low Cu2+. In addition, the Azu-OprC-mediated Cu2+ transport system is critical for P. aeruginosa cells in bacterial competition and virulence. Our findings provide insights for understanding the diverse functions of T6SSs and the role of metal ions for P. aeruginosa in bacteria-bacteria competition.
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Proteínas Bacterianas/metabolismo , Cobre/metabolismo , Proteínas de Unión al ADN/metabolismo , Pseudomonas aeruginosa/patogenicidad , Sistemas de Secreción Tipo VI/metabolismo , Virulencia/fisiología , Animales , Ratones , Infecciones por Pseudomonas/metabolismo , Pseudomonas aeruginosa/metabolismoRESUMEN
BACKGROUND: Pathological gaits of children may lead to terrible diseases, such as osteoarthritis or scoliosis. By monitoring the gait pattern of a child, proper therapeutic measures can be recommended to avoid the terrible consequence. However, low-cost systems for pathological gait recognition of children automatically have not been on market yet. Our goal was to design a low-cost gait-recognition system for children with only pressure information. METHODS: In this study, we design a pathological gait-recognition system (PGRS) with an 8 × 8 pressure-sensor array. An intelligent gait-recognition method (IGRM) based on machine learning and pure plantar pressure information is also proposed in static and dynamic sections to realize high accuracy and good real-time performance. To verifying the recognition effect, a total of 17 children were recruited in the experiments wearing PGRS to recognize three pathological gaits (toe-in, toe-out, and flat) and normal gait. Children are asked to walk naturally on level ground in the dynamic section or stand naturally and comfortably in the static section. The evaluation of the performance of recognition results included stratified tenfold cross-validation with recall, precision, and a time cost as metrics. RESULTS: The experimental results show that all of the IGRMs have been identified with a practically applicable degree of average accuracy either in the dynamic or static section. Experimental results indicate that the IGRM has 92.41% and 97.79% intra-subject recognition accuracy, and 85.78% and 78.81% inter-subject recognition accuracy, respectively, in the static and dynamic sections. And we find methods in the static section have less recognition accuracy due to the unnatural gesture of children when standing. CONCLUSIONS: In this study, a low-cost PGRS has been verified and realize feasibility, highly average precision, and good real-time performance of gait recognition. The experimental results reveal the potential for the computer supervision of non-pathological and pathological gaits in the plantar-pressure patterns of children and for providing feedback in the application of gait-abnormality rectification.
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Marcha , Caminata , Niño , Retroalimentación , Humanos , Aprendizaje AutomáticoRESUMEN
The second messenger cyclic diguanylate (c-di-GMP) plays a prominent role in regulating flagellum-dependent motility in the single-flagellated pathogenic bacterium Pseudomonas aeruginosa The c-di-GMP-mediated signaling pathways and mechanisms that control flagellar output remain to be fully unveiled. Studying surface-tethered and free-swimming P. aeruginosa PAO1 cells, we found that the overexpression of an exogenous diguanylate cyclase (DGC) raises the global cellular c-di-GMP concentration and thereby inhibits flagellar motor switching and decreases motor speed, reducing swimming speed and reversal frequency, respectively. We noted that the inhibiting effect of c-di-GMP on flagellar motor switching, but not motor speed, is exerted through the c-di-GMP-binding adaptor protein MapZ and associated chemotactic pathways. Among the 22 putative c-di-GMP phosphodiesterases, we found that three of them (DipA, NbdA, and RbdA) can significantly inhibit flagellar motor switching and swimming directional reversal in a MapZ-dependent manner. These results disclose a network of c-di-GMP-signaling proteins that regulate chemotactic responses and flagellar motor switching in P. aeruginosa and establish MapZ as a key signaling hub that integrates inputs from different c-di-GMP-signaling pathways to control flagellar output and bacterial motility. We rationalized these experimental findings by invoking a model that postulates the regulation of flagellar motor switching by subcellular c-di-GMP pools.
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GMP Cíclico/análogos & derivados , Flagelos/metabolismo , Proteínas Bacterianas/metabolismo , Biopelículas , Quimiotaxis/fisiología , GMP Cíclico/metabolismo , Proteínas de Escherichia coli/metabolismo , Flagelos/fisiología , Regulación Bacteriana de la Expresión Génica/genética , Metiltransferasas/metabolismo , Proteínas Motoras Moleculares/metabolismo , Hidrolasas Diéster Fosfóricas/metabolismo , Liasas de Fósforo-Oxígeno/metabolismo , Pseudomonas aeruginosa/metabolismo , Sistemas de Mensajero Secundario/fisiología , Transducción de Señal/genéticaRESUMEN
Dermal blood vessels and regional lymph nodes are innervated by sympathetic nerves and, under stress, sympathetic nerves release norepinephrine (NE). Exposure of primary murine dermal microvascular endothelial cells (pDMECs) to NE followed by co-culture with Langerhans cells (LCs), responsive CD4+ T-cells and antigen resulted in modulation of CD4+ T-cell responses. NE-treatment of pDMECs induced increased production of interleukin (IL)-6 and IL-17A while down-regulating interferon (IFN)-γ and IL-22 release. This effect did not require contact between pDMECs and LCs or T-cells and depended upon pDMEC production of IL-6. The presence of NE-treated pDMECs increased the proportion of CD4+ T-cells expressing intracellular IL-17A and increased IL-17A mRNA while decreasing the proportion of IFN-γ- or IL-22-expressing CD4+ T-cells and mRNA levels for those cytokines. Retinoic acid receptor-related orphan receptor gamma (ROR-γt) mRNA was significantly increased in CD4+ T-cells while T-box transcription factor (T-bet) mRNA was decreased. Intradermal administration of NE prior to hapten immunization at the injection site produced a similar bias in draining lymph node CD4+ T-cells towards IL-17A and away from IFN-γ and IL-22 production. Under stress, release of NE may have significant regulatory effects on the outcome of antigen presentation through actions on ECs with enhancement of inflammatory skin disorders involving IL-17/T helper type 17 (Th17) cells.
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Presentación de Antígeno , Comunicación Celular , Citocinas/inmunología , Células Endoteliales/efectos de los fármacos , Células de Langerhans/inmunología , Norepinefrina/farmacología , Linfocitos T Colaboradores-Inductores/inmunología , Animales , Células Cultivadas , Microambiente Celular , Técnicas de Cocultivo , Citocinas/genética , Citocinas/metabolismo , Células Endoteliales/inmunología , Células Endoteliales/metabolismo , Femenino , Genes Codificadores de los Receptores de Linfocitos T , Interleucina-17/inmunología , Interleucina-17/metabolismo , Interleucina-6/inmunología , Interleucina-6/metabolismo , Interleucinas/inmunología , Interleucinas/metabolismo , Células de Langerhans/metabolismo , Ganglios Linfáticos/efectos de los fármacos , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/metabolismo , Ratones Endogámicos BALB C , Ratones Transgénicos , Fenotipo , Linfocitos T Colaboradores-Inductores/metabolismo , Interleucina-22RESUMEN
Calcitonin gene-related peptide (CGRP) is a neuropeptide with well-established immunomodulatory functions. CGRP-containing nerves innervate dermal blood vessels and lymph nodes. We examined whether CGRP regulates the outcome of Ag presentation by Langerhans cells (LCs) to T cells through actions on microvascular endothelial cells (ECs). Exposure of primary murine dermal microvascular ECs (pDMECs) to CGRP followed by coculture with LCs, responsive CD4(+) T cells and Ag resulted in increased production of IL-6 and IL-17A accompanied by inhibition of IFN-γ, IL-4, and IL-22 compared with wells containing pDMECs treated with medium alone. Physical contact between ECs and LCs or T cells was not required for this effect and, except for IL-4, we demonstrated that IL-6 production by CGRP-treated pDMECs was involved in these effects. CD4(+) cells expressing cytoplasmic IL-17A were increased, whereas cells expressing cytoplasmic IFN-γ or IL-4 were decreased by the presence of CGRP-treated pDMECs. In addition, the level of retinoic acid receptor-related orphan receptor γt mRNA was significantly increased, whereas T-bet and GATA3 expression was inhibited. Immunization at the site of intradermally administered CGRP led to a similar bias in CD4(+) T cells from draining lymph node cells toward IL-17A and away from IFN-γ. Actions of nerve-derived CGRP on ECs may have important regulatory effects on the outcome of Ag presentation with consequences for the expression of inflammatory skin disorders involving Th17 cells.
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Presentación de Antígeno/inmunología , Péptido Relacionado con Gen de Calcitonina/inmunología , Células Endoteliales/inmunología , Células de Langerhans/inmunología , Activación de Linfocitos/inmunología , Células Th17/inmunología , Animales , Linfocitos T CD4-Positivos/inmunología , Femenino , Citometría de Flujo , Ratones , Ratones Endogámicos BALB C , Ratones Transgénicos , ARN Interferente Pequeño , Reacción en Cadena en Tiempo Real de la Polimerasa , TransfecciónRESUMEN
The bacterial messenger cyclic di-GMP (c-di-GMP) binds to a diverse range of effectors to exert its biological effect. Despite the fact that free-standing PilZ proteins are by far the most prevalent c-di-GMP effectors known to date, their physiological function and mechanism of action remain largely unknown. Here we report that the free-standing PilZ protein PA2799 from the opportunistic pathogen Pseudomonas aeruginosa interacts directly with the hybrid histidine kinase SagS. We show that PA2799 (named as HapZ: histidine kinase associated PilZ) binds directly to the phosphoreceiver (REC) domain of SagS, and that the SagS-HapZ interaction is further enhanced at elevated c-di-GMP concentration. We demonstrate that binding of HapZ to SagS inhibits the phosphotransfer between SagS and the downstream protein HptB in a c-di-GMP-dependent manner. In accordance with the role of SagS as a motile-sessile switch and biofilm growth factor, we show that HapZ impacts surface attachment and biofilm formation most likely by regulating the expression of a large number of genes. The observations suggest a previously unknown mechanism whereby c-di-GMP mediates two-component signaling through a PilZ adaptor protein.
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Proteínas Bacterianas/metabolismo , Biopelículas/crecimiento & desarrollo , GMP Cíclico/análogos & derivados , Histidina Quinasa/metabolismo , Pseudomonas aeruginosa/fisiología , Sistemas de Mensajero Secundario/fisiología , Proteínas Bacterianas/genética , GMP Cíclico/genética , GMP Cíclico/metabolismo , Histidina Quinasa/genéticaRESUMEN
Huanglongbing (HLB) is one of the most devastating diseases of citrus worldwide. The phloem-restricted bacterium Candidatus Liberibacter asiaticus (CLas) is considered to be the main pathogen responsible for HLB. There is currently no effective practical strategy for the control of HLB. Our understanding of how pathogens cause HLB is limited because CLas has not been artificially cultured. In this study, 15 potential virulence factors were predicted from the proteome of CLas through DeepVF and PHI-base searches. One among them, FlgI, was found to inhibit yeast growth when expressed in Saccharomyces cerevisiae. The expression of the signal peptide of FlgI fused with PhoA in Escherichia coli resulted in the discovery that FlgI was a novel Sec-dependent secretory protein. We further found that the carboxyl-terminal HA-tagged FlgI was secreted via outer membrane vesicles in Sinorhizobium meliloti. Fluoresence localization of transient expression FlgI-GFP in Nicotiana benthamiana revealed that FlgI is mainly localized in the cytoplasm, cell periphery, and nuclear periphery of tobacco cells. In addition, our experimental results suggest that FlgI has a strong ability to induce callose deposition and cell necrosis in N. benthamiana. Finally, by screening a large library of compounds in a high-throughput format, we found that cyclosporin A restored the growth of FlgI-expressing yeast. These results confirm that FlgI is a novel Sec-dependent effector, enriching our understanding of CLas pathogenicity and helping to develop new and more effective strategies to manage HLB.
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PURPOSE: The aim of this study was to develop and validate radiomics signatures based on MRI for preoperative prediction of Ki-67 proliferative index (PI) expression in primary central nervous system lymphoma (PCNSL). METHODS: A total of 341 patients with PCNSL were retrospectively analyzed, including 286 patients in one center as the training set and 55 patients in another two centers as the external validation set. Radiomics features were extracted and selected from preoperative contrast-enhanced T1-weighted images, fluid attenuation inversion recovery to build radiomics signatures according to the Ki-67 PI. The predictive performances of the radiomics model were evaluated using four classifiers including random forest, K-Nearest Neighbors, Neural Network and Decision Tree. A combined model was built by incorporating radiomics signature, clinical variables and MRI radiological characteristics using multivariate logistic regression analysis, and a nomogram was established to predict the expression of Ki-67 individually. The predictive performances of the models were evaluated using area under receiver operating characteristic curve (AUC) and decision curve analysis (DCA). RESULTS: Radiomics signatures were independent predictors of the expression level of Ki-67 (OR: 2.523, P < 0.001). RF radiomics models had the highest accuracy (0.934 in the training set and 0.811 in the external validation set) and F1 Score (0.920 in the training set and 0.836 in the external validation set). The clinic-radiologic-radiomics nomogram showed better predictive performance with AUCs of 0.877(95 % CI: 0.837-0.918) in the training set and 0.866(95 % CI: 0.774-0.957) in the external validation set. The calibration curve and DCA demonstrated goodness-of-fit and improved benefits in clinical practice of the nomogram. CONCLUSIONS: Nomograms integrating MRI-based radiomics and clinical-radiological characteristics could effectively predict Ki-67 PI in primary PCNSL.
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Neoplasias del Sistema Nervioso Central , Antígeno Ki-67 , Linfoma , Radiómica , Humanos , Neoplasias del Sistema Nervioso Central/diagnóstico por imagen , Neoplasias del Sistema Nervioso Central/metabolismo , Antígeno Ki-67/metabolismo , Linfoma/diagnóstico por imagen , Linfoma/metabolismo , Imagen por Resonancia Magnética/métodos , Nomogramas , Valor Predictivo de las Pruebas , Estudios RetrospectivosRESUMEN
The second messenger cyclic diguanylate monophosphate (c-di-GMP) regulates a wide range of bacterial behaviours through diverse mechanisms and binding receptors. Single-domain PilZ proteins, the most widespread and abundant known c-di-GMP receptors in bacteria, act as trans-acting adaptor proteins that enable c-di-GMP to control signalling pathways with high specificity. This study identifies a single-domain PilZ protein, XAC3402 (renamed N5MapZ), from the phytopathogen Xanthomonas citri subsp. citri (Xcc), which modulates Xcc virulence by directly interacting with the methyltransferase HemK. Through yeast two-hybrid, co-immunoprecipitation and immunofluorescent staining, we demonstrated that N5MapZ and HemK interact directly under both in vitro and in vivo conditions, with the strength of the protein-protein interaction decreasing at high c-di-GMP concentrations. This finding distinguishes N5MapZ from other characterized single-domain PilZ proteins, as it was previously known that c-di-GMP enhances the interaction between those single-domain PilZs and their protein partners. This observation is further supported by the fact that the c-di-GMP binding-defective mutant N5MapZR10A can interact with HemK to inhibit the methylation of the class 1 translation termination release factor PrfA. Additionally, we found that HemK plays an important role in Xcc pathogenesis, as the deletion of hemK leads to extensive phenotypic changes, including reduced virulence in citrus plants, decreased motility, production of extracellular enzymes and stress tolerance. Gene expression analysis has revealed that c-di-GMP and the HemK-mediated pathway regulate the expression of multiple virulence effector proteins, uncovering a novel regulatory mechanism through which c-di-GMP regulates Xcc virulence by mediating PrfA methylation via the single-domain PilZ adaptor protein N5MapZ.
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Proteínas Bacterianas , GMP Cíclico , Metiltransferasas , Xanthomonas , Xanthomonas/patogenicidad , Xanthomonas/metabolismo , Xanthomonas/genética , GMP Cíclico/metabolismo , GMP Cíclico/análogos & derivados , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genética , Metiltransferasas/metabolismo , Metiltransferasas/genética , Virulencia , Enfermedades de las Plantas/microbiología , Unión ProteicaRESUMEN
Diabetic nephropathy (DN) is a common complication of diabetes, characterized by renal fibrosis and poor patient prognosis. Hederagenin (HDG) has shown promising improvement in chronic kidney disease (CKD) kidney fibrosis, but its mechanism in DN-induced kidney fibrosis remains unclear. In this study, a model of diabetic nephropathy (DN) in mice was induced by intraperitoneal injection of streptozocin (50 mg/kg), while in vitro, high glucose (25 mM) was used to induce HK2 cell damage, simulating tubular injury in DN kidneys. The improvement of HDG treatment intervention was evaluated by observing changes in renal function, pathological structural damage, and the expression of fibrosis-related proteins in renal tubular cells. The results demonstrate that HDG intervention alleviates renal dysfunction and pathological damage in DN mice, accompanied by reduced expression of fibrotic markers α-smooth muscle actin (α-SMA), fibronectin (FN) and Collagen-I. Mechanistically, this study found that HDG can inhibit ferroptosis and fibrosis induced by the ferroptosis inducer Erastin (1 µM) in renal tubular cells. Phosphorylation of Smad3 promotes ferroptosis in renal tubular cells. After using its specific inhibitor SIS3 (4 µM), the expression of downstream target protein NADPH oxidase 4 (NOX4) significantly decreases, while the level of glutathione peroxidase 4 (GPX4) is notably restored, mitigating ferroptosis. Smad3 overexpression attenuates the therapeutic effect of HDG on tubular cell fibrosis induced by high glucose. These results demonstrate HDG inhibits Smad3 phosphorylation, thereby reducing the expression of NOX4 and enhancing the expression of GPX4, ultimately attenuating ferroptosis induced renal fibrosis. These findings suggest that HDG offer therapeutic potential for DN renal fibrosis by targeting Smad3-mediated ferroptosis in renal tubular cells.
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Nefropatías Diabéticas , Ferroptosis , Fibrosis , Ratones Endogámicos C57BL , NADPH Oxidasa 4 , Ácido Oleanólico , Transducción de Señal , Proteína smad3 , Animales , Ferroptosis/efectos de los fármacos , Proteína smad3/metabolismo , Nefropatías Diabéticas/tratamiento farmacológico , Nefropatías Diabéticas/patología , Nefropatías Diabéticas/metabolismo , NADPH Oxidasa 4/metabolismo , NADPH Oxidasa 4/genética , Humanos , Ratones , Transducción de Señal/efectos de los fármacos , Masculino , Línea Celular , Ácido Oleanólico/análogos & derivados , Ácido Oleanólico/farmacología , Ácido Oleanólico/uso terapéutico , Túbulos Renales/patología , Túbulos Renales/efectos de los fármacos , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Mellitus Experimental/metabolismoRESUMEN
Disruption of the cell cycle is a common strategy shared by many viruses to create a conducible cellular microenvironment for their efficient replication. We have previously shown that infection of cells with gammacoronavirus infectious bronchitis virus (IBV) activated the theataxia-telangiectasia mutated (ATM) Rad3-related (ATR)/checkpoint kinase 1 (Chk1) pathway and induced cell cycle arrest in S and G2/M phases, partially through the interaction of nonstructural protein 13 (nsp13) with the p125 catalytic subunit of DNA polymerase delta (pol δ). In this study, we show, by GST pulldown, co-immunoprecipitation and immunofluorescent staining, that IBV nsp12 directly interacts with the p50 regulatory subunit of pol δ in vitro and in cells overexpressing the two proteins as well as in cells infected with a recombinant IBV harbouring an HA-tagged nsp12. Furthermore, nsp12 from severe acute respiratory syndrome coronavirus (SARS-CoV) and SARS-CoV-2 was also able to interact with p50. These interactions play a synergistic role with nsp13 in the induction of S phase arrest. The fact that subunits of an essential cellular DNA replication machinery physically associate with two core replication enzymes from three different coronaviruses highlights the importance of these associations in coronavirus replication and virus-host interaction, and reveals the potential of targeting these subunits for antiviral intervention.
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COVID-19 , Virus de la Bronquitis Infecciosa , Humanos , ADN Polimerasa III/química , ADN Polimerasa III/genética , ADN Polimerasa III/metabolismo , Fase S , ARN Polimerasa Dependiente de ARN de Coronavirus , ARN Helicasas/genética , ARN Helicasas/metabolismo , SARS-CoV-2/metabolismo , Puntos de Control del Ciclo Celular , Virus de la Bronquitis Infecciosa/genética , Virus de la Bronquitis Infecciosa/metabolismo , Daño del ADNRESUMEN
Introduction: Human-in-the-loop optimization has made great progress to improve the performance of wearable robotic devices and become an effective customized assistance strategy. However, a lengthy period (several hours) of continuous walking for iterative optimization for each individual makes it less practical, especially for disabled people, who may not endure this process. Methods: In this paper, we provide a muscle-activity-based human-in-the-loop optimization strategy that can reduce the time spent on collecting biosignals during each iteration from around 120 s to 25 s. Both Bayesian and Covariance Matrix Adaptive Evolution Strategy (CMA-ES) optimization algorithms were adopted on a portable hip exoskeleton to generate optimal assist torque patterns, optimizing rectus femoris muscle activity. Four volunteers were recruited for exoskeleton-assisted walking trials. Results and Discussion: As a result, using human-in-the-loop optimization led to muscle activity reduction of 33.56% and 41.81% at most when compared to walking without and with the hip exoskeleton, respectively. Furthermore, the results of human-in-the-loop optimization indicate that three out of four participants achieved superior outcomes compared to the predefined assistance patterns. Interestingly, during the optimization stage, the order of the two typical optimizers, i.e., Bayesian and CMA-ES, did not affect the optimization results. The results of the experiment have confirmed that the assistance pattern generated by muscle-activity-based human-in-the-loop strategy is superior to predefined assistance patterns, and this strategy can be achieved more rapidly than the one based on metabolic cost.
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Indian mustard (Brassica juncea L. Czern and Coss) is an important oil and vegetable crop frequently affected by seasonal drought stress during seed germination, which retards plant growth and causes yield loss considerably. However, the gene networks regulating responses to drought stress in leafy Indian mustard remain elusive. Here, we elucidated the underlying gene networks and pathways of drought response in leafy Indian mustard using next-generation transcriptomic techniques. Phenotypic analysis showed that the drought-tolerant leafy Indian mustard cv. 'WeiLiang' (WL) had a higher germination rate, antioxidant capacity, and better growth performance than the drought-sensitive cv. 'ShuiDong' (SD). Transcriptome analysis identified differentially expressed genes (DEGs) in both cultivars under drought stress during four germination time points (i.e., 0, 12, 24, and 36 h); most of which were classified as drought-responsive, seed germination, and dormancy-related genes. In the Kyoto Encyclopedia of Genes and Genome (KEGG) analyses, three main pathways (i.e., starch and sucrose metabolism, phenylpropanoid biosynthesis, and plant hormone signal transduction) were unveiled involved in response to drought stress during seed germination. Furthermore, Weighted Gene Co-expression Network Analysis (WGCNA) identified several hub genes (novel.12726, novel.1856, BjuB027900, BjuA003402, BjuA021578, BjuA005565, BjuB006596, novel.12977, and BjuA033308) associated with seed germination and drought stress in leafy Indian mustard. Taken together, these findings deepen our understanding of the gene networks for drought responses during seed germination in leafy Indian mustard and provide potential target genes for the genetic improvement of drought tolerance in this crop.
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Germinación , Transcriptoma , Germinación/genética , Planta de la Mostaza/genética , Planta de la Mostaza/metabolismo , Sequías , Semillas , Perfilación de la Expresión Génica , Hormonas/metabolismo , Regulación de la Expresión Génica de las PlantasRESUMEN
Interstitial fibrosis is the key pathological characteristics of chronic kidney diseases (CKD). In this study, we reported that hederagenin (HDG) can effectively improve the renal interstitial fibrosis and its mechanism. We constructed CKD animal models of ischemia reperfusion injury (IRI) and unilateral ureteral obstruction (UUO) respectively to observe the improvement effect of HDG on CKD. The results showed that HDG can effectively improve the pathological structure of kidney and the renal fibrosis in CKD mice. Meanwhile, HDG can also significantly reduce the expression of α-SMA and FN induced by TGF-ß in Transformed C3H Mouse Kidney-1 (TCMK1) cells. Mechanistically, we performed transcriptome sequencing on UUO kidneys treated with HDG. By real time PCR screening of the sequencing results, we determined that ISG15 plays an important role in the intervention of HDG in CKD. Subsequently, we knocked-down ISG15 in TCMK1 and found that ISG15 knock-down significantly inhibited TGF-ß-induced fibrotic protein expression and JAK/STAT activation. Finally, we performed electrotransfection and used liposomes to transfect ISG15 overexpression plasmids to up-regulate ISG15 in kidney and cells, respectively. We found that ISG15 can aggravate renal tubular cell fibrosis and abolish the protection of HDG on CKD. These results indicated that HDG significantly improves renal fibrosis in CKD by inhibiting ISG15 and its downstream JAK/STAT signaling pathway, which provides a new drug and research target for the subsequent treatment of CKD.
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Insuficiencia Renal Crónica , Obstrucción Ureteral , Ratones , Animales , Ratones Endogámicos C3H , Riñón/patología , Insuficiencia Renal Crónica/patología , Obstrucción Ureteral/tratamiento farmacológico , Transducción de Señal , Factor de Crecimiento Transformador beta/metabolismo , Fibrosis , Factor de Crecimiento Transformador beta1/metabolismoRESUMEN
Type IV pili (T4P) are polar surface structures that play important roles in bacterial motility, biofilm formation, and pathogenicity. The protein FimX and its orthologs are known to mediate T4P formation in the human pathogen Pseudomonas aeruginosa and some other bacterial species. It was reported recently that FimX(XAC2398) from Xanthomonas axonopodis pv. citri interacts with PilZ(XAC1133) directly through the nonenzymatic EAL domain of FimX(XAC2398). Here we present experimental data to reveal that the strong interaction between FimX(XAC2398) and PilZ(XAC1133) is not conserved in P. aeruginosa and likely other Pseudomonas species. In vitro and in vivo binding experiments showed that the interaction between FimX and PilZ in P. aeruginosa is below the measurable limit. Surface plasmon resonance assays further confirmed that the interaction between the P. aeruginosa proteins is at least more than 3 orders of magnitude weaker than that between the X. axonopodis pv. citri pair. The N-terminal lobe region of FimX(XAC2398) was identified as the binding surface for PilZ(XAC1133) by amide hydrogen-deuterium exchange and site-directed mutagenesis studies. Lack of several key residues in the N-terminal lobe region of the EAL domain of FimX is likely to account for the greatly reduced binding affinity between FimX and PilZ in P. aeruginosa. All together, the results suggest that the interaction between PilZ and FimX in Xanthomonas species is not conserved in P. aeruginosa due to the evolutionary divergence among the FimX orthologs. The precise roles of FimX and PilZ in bacterial motility and T4P biogenesis are likely to vary among bacterial species.
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Proteínas Bacterianas/metabolismo , Fimbrias Bacterianas/metabolismo , Mapeo de Interacción de Proteínas , Pseudomonas aeruginosa/fisiología , Xanthomonas axonopodis/fisiología , Secuencia de Aminoácidos , Proteínas Bacterianas/genética , Modelos Moleculares , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Unión Proteica , Conformación Proteica , Alineación de Secuencia , Resonancia por Plasmón de SuperficieRESUMEN
Background: Thirty per cent supramolecular salicylic acid (SSA) is a water-soluble, sustained release salicylic acid (SA) modality, which is well tolerated by sensitive skin. Anti-inflammatory therapy plays an important role in papulopustular rosacea (PPR) treatment. SSA at a 30% concentration has a natural antiinflammatory property. Aims: This study aims to investigate the efficacy and safety of 30% SSA peeling for PPR treatment. Methods: Sixty PPR patients were randomly divided into two groups: SSA group (30 cases) and control group (30 cases). Patients of the SSA group were treated with 30% SSA peeling three times every 3 weeks. Patients in both groups were instructed to topically apply 0.75% metronidazole gel twice daily. Transdermal water loss (TEWL), skin hydration and erythema index were assessed after 9 weeks. Results: Fifty-eight patients completed the study. The improvement of erythema index in the SSA group was significantly better than that in the control group. No significant difference was found in terms of TEWL between the two groups. The content of skin hydration in both the groups increased, but there was no statistical significance. No severe adverse events were observed in both the groups. Conclusion: SSA can significantly improve the erythema index and overall appearance of skin in rosacea patients. It has a good therapeutic effect, good tolerance and high safety.
RESUMEN
OBJECTIVE: Neuropathic pain (NP) plays an important role in patients with knee osteoarthritis (KOA). However, the prevalence of NP at different treatment stages including outpatient, awaiting and after total knee arthroplasty (TKA) have not been compared. The understanding of this issue and identify risk factors can help physicians develop individualized strategies to manage the pain of KOA. Therefore, the aim of the study is to investigate the prevalence and risk factors of NP at different treatment stages of KOA. METHODS: Patients diagnosed as KOA between August 2016 and August 2020 were enrolled in this cross-sectional study and divided into three groups according to treatment stage, including outpatient stage, awaiting TKA stage (pre-TKA) and after TKA stage (post-TKA). A numeric rating scale (NRS) and PainDETECT questionnaire were used to evaluate nociceptive pain and NP. Patient demographics, radiological assessments using Kellgren-Lawrence (K-L) grade, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were analyzed. Data analysis and statistics were processed using SPSS 20.0 and examined by ANOVA with/without Bonferroni correction or Kruskal-Wallis test. A chi-square test was used to determine cross-table data and calculate the odds ratio (OR) value. RESULTS: Of the 921 patients, the prevalence of possible and likely NP was 17.5% (56/320) and 2.5% (8/320) in the pre-TKA group compared with 3.4% (8/233) and 0.4% (1/233) in the outpatient group and 1.4% (5/368) and 0.5% (2/368) in the post-TKA group, respectively. In the pre-TKA group, higher NRS (NRS >3; OR = 10.65, 95% CI: 3.25-34.92, P < 0.001) and WOMAC pain score (score > 10; OR = 4.88, 95% CI: 2.38-10.01, P < 0.001) conferred an increased risk of unclear pain. Age, gender, BMI and K-L grade showed no significant differences among the unlikely, possible and likely NP groups. CONCLUSION: Prevalence of NP is different at stages of out-patient, awaiting and after TKA in patients with KOA. Patients awaiting TKA have the highest prevalence of NP compared with patients in outpatient and post-TKA groups. In the patients waiting for TKA, higher NRS (NRS >3) and WOMAC pain scores (score > 10) are risk factors of NP.
Asunto(s)
Artroplastia de Reemplazo de Rodilla , Neuralgia , Osteoartritis de la Rodilla , Humanos , Osteoartritis de la Rodilla/cirugía , Pacientes Ambulatorios , Prevalencia , Estudios Transversales , Neuralgia/cirugía , Factores de Riesgo , Articulación de la Rodilla/cirugía , Resultado del TratamientoRESUMEN
The aging population is now a global challenge, and impaired walking ability is a common feature in the elderly. In addition, some occupations such as military and relief workers require extra physical help to perform tasks efficiently. Robotic hip exoskeletons can support ambulatory functions in the elderly and augment human performance in healthy people during normal walking and loaded walking by providing assistive torque. In this review, the current development of robotic hip exoskeletons is presented. In addition, the framework of actuation joints and the high-level control strategy (including the sensors and data collection, the way to recognize gait phase, the algorithms to generate the assist torque) are described. The exoskeleton prototypes proposed by researchers in recent years are organized to benefit the related fields realizing the limitations of the available robotic hip exoskeletons, therefore, this work tends to be an influential factor with a better understanding of the development and state-of-the-art technology.