RESUMEN
Extraintestinal pathogenic Escherichia coli (ExPEC) is a well-known critical pathogenic zoonosis that causes extraintestinal infections in humans and animals by affecting their immune organs. Recently, research on the outer membrane protein of E. coli, tolerant colicin (TolC), a virulent protein in the formation of the ExPEC efflux pump, has been an attractive subject. However, the pathogenic mechanisms remain unclear. This study aimed to explore the role of TolC in the pathogenesis of the ExPEC strain PPECC42; a complementation strain (Cm-TolC) and an isogenic mutant (ΔTolC) were constructed. Loss of TolC drastically impaired the virulence of ExPEC in an experimental mouse model. ΔTolC showed a substantial decrease in the porcine aortic vascular endothelial cell (PAVEC) adherence, invasion, and pro-inflammatory response, in contrast to that of the wild type, with a reduced survival ratio in both the bacterial load and whole blood in mice. ΔTolC also showed decreased expression of necroptosis signals such as receptor-interacting protein kinase 1, phosphorylated mixed-lineage kinase domain-like protein, and mitochondrial proteins such as phosphoglycerate mutase family member 5. Our data suggest that TolC is closely associated with ExPEC pathogenesis. These results provide scientific grounds for exploring the potential of TolC as an effective drug target for controlling ExPEC infection, screening new inhibitors, and developing new drugs. This will allow for further prevention and control of ExPEC infection.
Asunto(s)
Colicinas , Infecciones por Escherichia coli , Escherichia coli Patógena Extraintestinal , Animales , Colicinas/metabolismo , Escherichia coli/genética , Infecciones por Escherichia coli/microbiología , Escherichia coli Patógena Extraintestinal/metabolismo , Humanos , Ratones , Porcinos , VirulenciaRESUMEN
This study assessed the molecular mechanism of EPA or DHA protection against intestinal porcine epithelial cell line 1 (IPEC-1) cell damage induced by deoxynivalenol (DON). The cells were divided into six groups, including the CON group, the EPA group, the DHA group, the DON group, the EPA + DON group and the DHA + DON group. RNA sequencing was used to investigate the potential mechanism, and qRT-PCR was employed to verify the expression of selected genes. Changes in ultrastructure were used to estimate pathological changes and endoplasmic reticulum (ER) injury in IPEC-1 cells. Transferrin receptor 1 (TFR1) was tested by ELISA. Fe2+ and malondialdehyde (MDA) contents were estimated by spectrophotometry, and reactive oxygen species (ROS) was assayed by fluorospectrophotometry. RNA sequencing analysis showed that EPA and DHA had a significant effect on the expression of genes involved in ER stress and iron balance during DON-induced cell injury. The results showed that DON increased ER damage, the content of MDA and ROS, the ratio of X-box binding protein 1s (XBP-1s)/X-box binding protein 1u (XBP-1u), the concentration of Fe2+ and the activity of TFR1. However, the results also showed that EPA and DHA decreased the ratio of XBP-1s/XBP-1u to relieve DON-induced ER damage of IPEC-1 cells. Moreover, EPA and DHA (especially DHA) reversed the factors related to iron balance. It can be concluded that EPA and DHA reversed IPEC-1 cell damage induced by DON. DHA has the potential to protect IPEC-1 cells from DON-induced iron imbalance by inhibiting ER stress.
Asunto(s)
Intestinos , Tricotecenos , Animales , Porcinos , Especies Reactivas de Oxígeno/metabolismo , Tricotecenos/metabolismo , Tricotecenos/farmacología , Células Epiteliales/metabolismo , Estrés del Retículo EndoplásmicoRESUMEN
To test the dynamic changes of the expression of genes and microRNA in the gastrocnemius muscle after LPS challenge, 36 piglets were assigned to a control group (slaughtered 0 h after saline injection) and LPS groups (slaughtered at 1 h, 2 h, 4 h, 8 h, and 12 h after LPS treatment, respectively). After LPS treatment, the mRNA expression of IL-1ß, IL-6, and TNF-α reached maximal levels at 1 h, 2 h, and 1 h, respectively (P < 0.05), and mRNA expression of TLR4, NODs, muscle-specific ring finger 1, and muscle atrophy F-box peaked at 12 h (P < 0.05). Moreover, the expression of miR-122, miR-135a, and miR-370 reduced at 1 h, 1 h, and 2 h, respectively (P < 0.05), and miR-34a, miR-224, miR-132, and miR-145 reached maximum expression levels at 1 h, 1 h, 2 h, and 4 h, respectively (P < 0.05). These results suggested that mRNA expression of pro-inflammatory cytokines was elevated in the early stage, mRNA expression of genes related to TLR4 and NODs signaling pathways and protein degradation increased in the later phase, and the expression of microRNA related to muscle inflammation and protein degradation changed in the early stage after LPS injection.
Asunto(s)
Regulación de la Expresión Génica/genética , Lipopolisacáridos/toxicidad , MicroARNs/biosíntesis , MicroARNs/genética , Proteínas Musculares/genética , Miositis/genética , Animales , Citocinas/biosíntesis , Citocinas/genética , Cinética , Masculino , Proteínas Musculares/metabolismo , Miositis/patología , Proteínas Adaptadoras de Señalización NOD/genética , Transducción de Señal/genética , Porcinos , Receptor Toll-Like 4/genética , Receptor Toll-Like 4/metabolismoRESUMEN
In the present study, we used microRNA (miRNA) sequencing to discover and explore the expression profiles of known and novel miRNAs in 1000 ng/ml LPS stimulated for 8 h vis-à-vis non-stimulated (i.e. control) PBMCs isolated from the blood of healthy pigs. A total of 291 known miRNAs were bio-computationally identified in porcine PBMCs, and 228 novel miRNAs (not enlisted in the swine mirBase) were identified. Among these miRNAs, ssc-miR-148a-3p, ssc-let-7g, ssc-let-7f, 3_8760, ssc-miR-26a, ssc-miR-451, ssc-miR-21, ssc-miR-30d, ssc-miR-99a and ssc-miR-103 were the top 10 most abundant miRNAs in porcine PBMCs. Through miRNA differential analysis combined with quantitative PCR, we found the expressions of ssc-miR-122, ssc-miR-129b, ssc-miR-17-5p and ssc-miR-152 were significantly changed in porcine PBMCs after LPS stimulation. Furthermore, targets prediction and function analysis indicated a significant enrichment in gene ontology functional categories related to diseases, immunity and inflammation. In conclusion, this study on profiling of miRNAs expressed in LPS-stimulated PBMCs provides an important reference point for future studies on regulatory roles of miRNAs in porcine immune system.
Asunto(s)
Leucocitos Mononucleares/inmunología , MicroARNs/genética , Porcinos/inmunología , Animales , Células Cultivadas , Regulación de la Expresión Génica/inmunología , Ontología de Genes , Inmunidad/genética , Inmunización , Lipopolisacáridos/metabolismo , Análisis de Secuencia de ARN , TranscriptomaRESUMEN
In order to find an effective, stable, environmentally compatible electrode for the elimination of organic pollutants, preparation of a novel graphite electrode (NGE) was explored using graphite, epoxy resin, curing agent and acetone as materials. Water, ethanol aqueous solution, acetone, ultrasound-acetone and electrochemical method were used to pretreat the electrode. The first three methods obtained poor effect. Ultrasound-acetone could improve the pretreatment, but satisfied results were difficult to achieve. Electrochemical method could work effectively. Electrochemical oxidation of phenol was carried out on NGE and commercial graphite electrode (CGE), respectively. UV spectroscopy was used to study evolution of phenol oxidation. The results showed that CGE resulted in accumulation of bensoquine in the electrolyte, though it was more effective than NGE on phenol oxidation. While much less benzoquinone was found in the electrolyte for NGE. TOC removal rate were 40% and 31% for NGE and CGE, respectively. SEM study showed that CGE was severely corroded after phenol degradation, while NGE was undamaged, showing good stability.
Asunto(s)
Electroquímica/instrumentación , Electrodos , Grafito , Fenol/aislamiento & purificación , Eliminación de Residuos Líquidos/métodos , Electrólitos , Diseño de Equipo , Residuos Industriales , Oxidación-Reducción , Fenol/química , Compuestos de Amonio Cuaternario/química , Compuestos de Amonio Cuaternario/aislamiento & purificación , Purificación del Agua/instrumentaciónRESUMEN
Activated carbon fiber prepared from cotton stalk was used as an adsorbent for the removal of p-nitroaniline (PNA) from aqueous solutions. Liquid phase adsorption experiments were conducted and the maximum adsorptive capacity was determined. The effect of experimental parameters such as pH, salinity and temperature on the adsorption was studied. The obtained experimental data were then fitted with the Langmuir, Freundlich and Redlich-Peterson models to describe the equilibrium isotherms. The kinetics rates were modeled by using the pseudo-first-order and pseudo-second-order equations. The results indicated that cotton stalk activated carbon fiber (CS-ACF) is an effective adsorbent for the removal of PNA from aqueous solutions. The maximum adsorption capacity of 406 mg g(-1) was achieved at the initial PNA concentration of 200 mg L(-1). The optimum pH for the removal of PNA was found to be 7.6. The presence of ammonium chloride proved to be favorable for the process of adsorption. The adsorption amount decreased with increasing temperature. The Redlich-Peterson model was found to best represent the equilibrium data. The kinetic data followed closely the pseudo-second-order equation. Thermodynamic study showed the adsorption was a spontaneous exothermic physical process.
Asunto(s)
Compuestos de Anilina/aislamiento & purificación , Carbón Orgánico/química , Gossypium/química , Contaminantes Químicos del Agua/aislamiento & purificación , Adsorción , Soluciones , Purificación del Agua/métodosRESUMEN
Activated carbon prepared from cotton stalk fibre has been utilized as an adsorbent for the removal of 2-nitroaniline from aqueous solutions. The influence of adsorbent mass, contact time and temperature on the adsorption was investigated by conducting a series of batch adsorption experiments. The equilibrium data at different temperatures were fitted with the Langmuir, Freundlich, Tempkin, Redlich-Peterson and Langmuir-Freundlich models. The Langmuir-Freundlich isotherm was found to best describe the experimental data. The adsorption amount increased with increasing temperature. The maximum adsorption capacity of 2-nitroaniline was found to be 383 mg/g for initial 2-nitroaniline concentration of 200mg/L at 45 degrees C. The kinetic rates were modeled by using the Lagergren-first-order, pseudo-second-order and Elovich models. The pseudo-second-order model was found to explain the adsorption kinetics most effectively. It was also found that the pore diffusion played an important role in the adsorption, and intraparticle diffusion was the rate-limiting step at the first 30 min for the temperatures of 25, 35 and 45 degrees C. FTIR and (13)C NMR study revealed that the amino and isocyanate groups present on the surface of the adsorbent were involved in chemical interaction with 2-nitroaniline. The negative change in free energy (Delta G degrees) and positive change in enthalpy (Delta H degrees) indicated that the adsorption was a spontaneous and endothermic process.
Asunto(s)
Compuestos de Anilina/aislamiento & purificación , Carbón Orgánico/síntesis química , Fibra de Algodón , Contaminantes del Agua/aislamiento & purificación , Adsorción , Carbón Orgánico/química , Difusión , Cinética , Porosidad , Soluciones , Temperatura , Termodinámica , Purificación del Agua/métodosRESUMEN
To study the chemical constituents of Fritillaria monanth Migo, the constituents were separated and purified by column chromatography on silica gel, and the structures were identified by NMR, MS spectral data. Six compounds were isolated and identified as ent-kauran-15-en-17-ol (I), entkauran-15-en-3alpha, 17-diol (II), fritillaziebinol (III), ent-kauran-16a, 17-diol (IV), ent-kauran-3alpha, 16alpha,17-triol (V), ent-16,17-epoxy-kauran-3alpha-ol (VI). All the compounds were isolated from this plant for the first time, and VI is named as ent-16,17-epoxy-kauran-3alpha-ol, which is a new compound.
Asunto(s)
Diterpenos de Tipo Kaurano/aislamiento & purificación , Fritillaria/química , Diterpenos de Tipo Kaurano/química , Estructura Molecular , Raíces de Plantas/química , Plantas Medicinales/químicaRESUMEN
Electrokinetic remediation (EK) and its combined methods are emerging technologies to remove POPs from contaminated soils in situ in last decade. This paper reviews the five major kinds of electrokinetic remediation methods for POPs from contaminated soils: (1) Classic electrokinetic method; (2) Electrokinetic-Fenton method; (3) Electrokinetic remediation combining with bioremediation method; (4) Electrokinetic remediation combining with surfactants/cosolvents method; (5) Electrokinetic remediation combining with ultrasonic method. The basic principle, characteristics, application areas and research developments of those five methods are discussed respectively. The future development direction of EK remediation for POPs from contaminated soils is anticipated.