RESUMEN
The regular detection of weld seams in large-scale special equipment is crucial for improving safety and efficiency, and this can be achieved effectively through the use of weld seam tracking and detection robots. In this study, a wall-climbing robot with integrated seam tracking and detection was designed, and the wall climbing function was realized via a permanent magnet array and a Mecanum wheel. The function of weld seam tracking and detection was realized using a DeepLabv3+ semantic segmentation model. Several optimizations were implemented to enhance the deployment of the DeepLabv3+ semantic segmentation model on embedded devices. Mobilenetv2 was used to replace the feature extraction network of the original model, and the convolutional block attention module attention mechanism was introduced into the encoder module. All traditional 3×3 convolutions were substituted with depthwise separable dilated convolutions. Subsequently, the welding path was fitted using the least squares method based on the segmentation results. The experimental results showed that the volume of the improved model was reduced by 92.9%, only being 21.8 Mb. The average precision reached 98.5%, surpassing the original model by 1.4%. The reasoning speed was accelerated to 21 frames/s, satisfying the real-time requirements of industrial detection. The detection robot successfully realizes the autonomous identification and tracking of weld seams. This study remarkably contributes to the development of automatic and intelligent weld seam detection technologies.
RESUMEN
Dendritic cells can prime naive CD4+ T cells; however, here we demonstrate that dendritic cell-mediated priming was insufficient for the development of T helper type 2 cell-dependent immunity. We identify basophils as a dominant cell population that coexpressed major histocompatibility complex class II and interleukin 4 message after helminth infection. Basophilia was promoted by thymic stromal lymphopoietin, and depletion of basophils impaired immunity to helminth infection. Basophils promoted antigen-specific CD4+ T cell proliferation and interleukin 4 production in vitro, and transfer of basophils augmented the population expansion of helminth-responsive CD4+ T cells in vivo. Collectively, our studies suggest that major histocompatibility complex class II-dependent interactions between basophils and CD4+ T cells promote T helper type 2 cytokine responses and immunity to helminth infection.
Asunto(s)
Basófilos/inmunología , Linfocitos T CD4-Positivos/inmunología , Citocinas/inmunología , Antígenos de Histocompatibilidad Clase II/inmunología , Inmunidad/inmunología , Animales , Basófilos/citología , Basófilos/metabolismo , Antígeno CD11c/inmunología , Linfocitos T CD4-Positivos/citología , Linfocitos T CD4-Positivos/metabolismo , Comunicación Celular/inmunología , Proliferación Celular , Citocinas/metabolismo , Femenino , Citometría de Flujo , Expresión Génica , Antígenos de Histocompatibilidad Clase II/genética , Immunoblotting , Interleucina-4/genética , Interleucina-4/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos , Ratones Noqueados , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Esquistosomiasis mansoni/inmunología , Esquistosomiasis mansoni/parasitología , Células Th2/metabolismo , Timo/citología , Timo/inmunología , Tricuriasis/inmunología , Tricuriasis/parasitologíaRESUMEN
Reversed-phase liquid chromatography coupled with middle chromatogram isolated gel column was employed for the efficient preparative separation of the arylbutanoid-type phenol [(-)-rhododendrin] from Saxifraga tangutica. Universal C18 (XTerra C18) and XCharge C18 columns were compared for (-)-rhododendrin fraction analysis and preparation. Although tailing and overloading occurred on the XTerra C18 column, the positively charged reversed-phase C18 column (XCharge C18) overcame these drawbacks, allowing for favorable separation resolution, even when loading at a on a preparative scale (3.69 mg per injection). The general separation process was as follows. First, 365.0 mg of crude (-)-rhododendrin was enriched from 165 g Saxifraga tangutica extract via a middle chromatogram isolated gel column. Second, separation was performed on an XTerra C18 preparative column, from which 73.8 mg of the target fraction was easily obtained. Finally, the 24.0 mg tailing peak of (-)-rhododendrin on XTerra C18 column was selectively purified on the XCharge C18 analytical column. These results demonstrate that the tailing nonalkaloid peaks can be effectively used for preparative isolation on XCharge C18 columns.
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Glicósidos/aislamiento & purificación , Fenoles/aislamiento & purificación , Extractos Vegetales/aislamiento & purificación , Cromatografía de Fase Inversa , Geles/química , Glicósidos/química , Conformación Molecular , Fenoles/química , Extractos Vegetales/química , Saxifragaceae/química , EstereoisomerismoRESUMEN
This study presents an efficient strategy based on liquid-liquid extraction and pH-zone-refining counter-current chromatography for selective enrichment, separation, and purification of alkaloids and organic acids from natural products. First, an acid or base modified two-phase solvent system with maximum or minimum partition coefficient was developed for the liquid-liquid extraction of the crude extract. As a result, alkaloids or organic acids could be selectively enriched in the upper or lower phase. Then pH-zone-refining counter-current chromatography was employed to separate and purify the selectively enriched alkaloids or organic acids efficiently. The selective enrichment and separation of five bufadienolide from toad venom of Bufo marinus was used as an example to show the advantage of this strategy. As a result, 759 mg of selectively enriched bufadienolide was obtained from 2 g of crude extract and the total content of five targets was increased from 14.64 to 83%. A total of 31 mg of marinobufagin-3-adipoyl-l-arginine, 42 mg of telocinobufagin-3-pimeloyl-l-arginine, 51 mg of telocinobufagin-3-suberoyl-l-arginine, 132 mg of marinobufagin-3-suberoyl-l-arginine, and 57 mg of bufalin-3-suberoyl-l-arginine were all simultaneously separated from 500 mg of selectively enriched sample, with the purity of 92.4, 97.5, 90.3, 92.1, and 92.8%, respectively.
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Alcaloides/aislamiento & purificación , Productos Biológicos/aislamiento & purificación , Distribución en Contracorriente , Extracción Líquido-Líquido , Alcaloides/química , Animales , Productos Biológicos/química , Bufo marinus , Concentración de Iones de HidrógenoRESUMEN
Resistin-like molecule (RELM)α belongs to a family of secreted mammalian proteins that have putative immunomodulatory functions. Recent studies have identified a pathogenic role for RELMα in chemically induced colitis through effects on innate cell populations. However, whether RELMα regulates intestinal adaptive immunity to enteric pathogens is unknown. In this study, we employed Citrobacter rodentium as a physiologic model of pathogenic Escherichia coli-induced diarrheal disease, colitis, and Th17 cell responses. In response to Citrobacter, RELMα expression was induced in intestinal epithelial cells, infiltrating macrophages, and eosinophils of the infected colons. Citrobacter-infected RELMα(-/-) mice exhibited reduced infection-induced intestinal inflammation, characterized by decreased leukocyte recruitment to the colons and reduced immune cell activation compared with wild-type (WT) mice. Interestingly, Citrobacter colonization and clearance were unaffected in RELMα(-/-) mice, suggesting that the immune stimulatory effects of RELMα following Citrobacter infection were pathologic rather than host-protective. Furthermore, infected RELMα(-/-) mice exhibited decreased CD4(+) T cell expression of the proinflammatory cytokine IL-17A. To directly test whether RELMα promoted Citrobacter-induced intestinal inflammation via IL-17A, infected WT and IL-17A(-/-) mice were treated with rRELMα. RELMα treatment of Citrobacter-infected WT mice exacerbated intestinal inflammation and IL-17A expression whereas IL-17A(-/-) mice were protected from RELMα-induced intestinal inflammation. Finally, infected RELMα(-/-) mice exhibited reduced levels of serum IL-23p19 compared with WT mice, and RELMα(-/-) peritoneal macrophages showed deficient IL-23p19 induction. Taken together, these data identify a proinflammatory role for RELMα in bacterial-induced colitis and suggest that the IL-23/Th17 axis is a critical mediator of RELMα-induced inflammation.
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Citrobacter rodentium/inmunología , Inflamación/inmunología , Péptidos y Proteínas de Señalización Intercelular/inmunología , Interleucina-17/inmunología , Intestinos/efectos de los fármacos , Macrófagos Peritoneales/efectos de los fármacos , Células Th17/efectos de los fármacos , Inmunidad Adaptativa/efectos de los fármacos , Animales , Citrobacter rodentium/patogenicidad , Sulfato de Dextran , Eosinófilos/efectos de los fármacos , Eosinófilos/inmunología , Eosinófilos/patología , Células Epiteliales/efectos de los fármacos , Células Epiteliales/inmunología , Células Epiteliales/patología , Femenino , Expresión Génica/efectos de los fármacos , Inflamación/inducido químicamente , Inflamación/microbiología , Inflamación/patología , Péptidos y Proteínas de Señalización Intercelular/deficiencia , Péptidos y Proteínas de Señalización Intercelular/genética , Péptidos y Proteínas de Señalización Intercelular/farmacología , Interleucina-17/deficiencia , Interleucina-17/genética , Subunidad p19 de la Interleucina-23/sangre , Subunidad p19 de la Interleucina-23/inmunología , Intestinos/inmunología , Intestinos/microbiología , Macrófagos Peritoneales/inmunología , Macrófagos Peritoneales/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas Recombinantes/genética , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/farmacología , Células Th17/inmunología , Células Th17/patologíaRESUMEN
Aggregatibacter actinomycetemcomitans produces a repeats-in-toxin (RTX) leukotoxin (LtxA) that selectively kills human immune cells. Binding of LtxA to its ß2 integrin receptor (lymphocyte function-associated antigen-1 (LFA-1)) results in the clustering of the toxin·receptor complex in lipid rafts. Clustering occurs only in the presence of LFA-1 and cholesterol, and LtxA is unable to kill cells lacking either LFA-1 or cholesterol. Here, the interaction of LtxA with cholesterol was measured using surface plasmon resonance and differential scanning calorimetry. The binding of LtxA to phospholipid bilayers increased by 4 orders of magnitude in the presence of 40% cholesterol relative to the absence of cholesterol. The affinity was specific to cholesterol and required an intact secondary structure. LtxA contains two cholesterol recognition/amino acid consensus (CRAC) sites; CRAC(336) ((333)LEEYSKR(339)) is highly conserved among RTX toxins, whereas CRAC(503) ((501)VDYLK(505)) is unique to LtxA. A peptide corresponding to CRAC(336) inhibited the ability of LtxA to kill Jurkat (Jn.9) cells. Although peptides corresponding to both CRAC(336) and CRAC(503) bind cholesterol, only CRAC(336) competitively inhibited LtxA binding to this sterol. A panel of full-length LtxA CRAC mutants demonstrated that an intact CRAC(336) site was essential for LtxA cytotoxicity. The conservation of CRAC(336) among RTX toxins suggests that this mechanism may be conserved among RTX toxins.
Asunto(s)
Toxinas Bacterianas/química , Colesterol/química , Exotoxinas/química , Microdominios de Membrana/química , Pasteurellaceae/química , Secuencias de Aminoácidos , Toxinas Bacterianas/metabolismo , Colesterol/metabolismo , Exotoxinas/metabolismo , Humanos , Células Jurkat , Antígeno-1 Asociado a Función de Linfocito/química , Antígeno-1 Asociado a Función de Linfocito/metabolismo , Microdominios de Membrana/metabolismo , Pasteurellaceae/metabolismo , Unión Proteica , Resonancia por Plasmón de SuperficieRESUMEN
Nitric oxide (NO), a potent vasodilator, plays an important role in preventing hypoxia induced pulmonary hypertension. Endogenous NO is synthesized by nitric oxide synthases (NOSs) from l-arginine. In mammals, three different NOSs have been identified, including neuronal NOS (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS). Plateau pika (Ochotona curzoniae) is a typical hypoxia tolerant mammal that lives at 3000-5000 m above sea level on the Qinghai-Tibet Plateau. The aim of this study was to investigate whether NOS expression and NO production are regulated by chronic hypoxia in plateau pika. Quantitative real-time PCR and western blot analyses were conducted to quantify relative abundances of iNOS and eNOS transcripts and proteins in the lung tissues of plateau pikas at different altitudes (4550, 3950 and 3200 m). Plasma NO metabolites, nitrite/nitrate (NO(x)â») levels were also examined by Ion chromatography to determine the correlation between NO production and altitude level. The results revealed that iNOS transcript levels were significantly lower in animals at high altitudes (decreased by 53% and 57% at altitude of 3950 and 4550 m compared with that at 3200 m). Similar trends in iNOS protein abundances were observed (26% and 41% at 3950 and 4550 m comparing with at 3200 m). There were no significant differences in eNOS mRNA and protein levels in the pika lungs among different altitudes. The plasma NO(x)â» levels of the plateau pikas at high altitudes significantly decreased (1.65±0.19 µg/mL at 3200 m to 0.44±0.03 µg/mL at 3950 m and 0.24±0.01 µg/mL at 4550 m). This is the first evidence describing the effects of chronic hypoxia on NOS expression and NO levels in the plateau pika in high altitude adaptation. We conclude that iNOS expression and NO production are suppressed at high altitudes, and the lower NO concentration at high altitudes may serve crucial roles for helping the plateau pika to survive at hypoxic environment.
Asunto(s)
Altitud , Regulación Enzimológica de la Expresión Génica , Lagomorpha/metabolismo , Óxido Nítrico Sintasa de Tipo II/biosíntesis , Óxido Nítrico/biosíntesis , Animales , Hipoxia/sangre , Hipoxia/enzimología , Hipoxia/genética , Lagomorpha/sangre , Lagomorpha/genética , Pulmón/enzimología , Pulmón/metabolismo , Óxido Nítrico/sangre , Óxido Nítrico Sintasa de Tipo II/genética , TibetRESUMEN
The Gram-negative bacterium, Aggregatibacter actinomycetemcomitans, is a common inhabitant of the human upper aerodigestive tract. The organism produces an RTX (Repeats in ToXin) toxin (LtxA) that kills human white blood cells. LtxA is believed to be a membrane-damaging toxin, but details of the cell surface interaction for this and several other RTX toxins have yet to be elucidated. Initial morphological studies suggested that LtxA was bending the target cell membrane. Because the ability of a membrane to bend is a function of its lipid composition, we assessed the proficiency of LtxA to release of a fluorescent dye from a panel of liposomes composed of various lipids. Liposomes composed of lipids that form nonlamellar phases were susceptible to LtxA-induced damage while liposomes composed of lipids that do not form non-bilayer structures were not. Differential scanning calorimetry demonstrated that the toxin decreased the temperature at which the lipid transitions from a bilayer to a nonlamellar phase, while (31) P nuclear magnetic resonance studies showed that the LtxA-induced transition from a bilayer to an inverted hexagonal phase occurs through the formation of an isotropic intermediate phase. These results indicate that LtxA cytotoxicity occurs through a process of membrane destabilization.
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Toxinas Bacterianas/farmacología , Exotoxinas/farmacología , Membrana Dobles de Lípidos/química , Liposomas/química , Pasteurellaceae , Toxinas Bacterianas/química , Toxinas Bacterianas/metabolismo , Forma de la Célula/efectos de los fármacos , Exotoxinas/química , Exotoxinas/metabolismo , Fluoresceínas/química , Colorantes Fluorescentes/química , Humanos , Células Jurkat , Microvellosidades/efectos de los fármacos , Microvellosidades/ultraestructura , Transición de Fase , Fosfatidilcolinas/química , Fosfatidiletanolaminas/químicaRESUMEN
Intestinal epithelial cells (IECs) provide a primary physical barrier against commensal and pathogenic microorganisms in the gastrointestinal (GI) tract, but the influence of IECs on the development and regulation of immunity to infection is unknown. Here we show that IEC-intrinsic IkappaB kinase (IKK)-beta-dependent gene expression is a critical regulator of responses of dendritic cells and CD4+ T cells in the GI tract. Mice with an IEC-specific deletion of IKK-beta show a reduced expression of the epithelial-cell-restricted cytokine thymic stromal lymphopoietin in the intestine and, after infection with the gut-dwelling parasite Trichuris, fail to develop a pathogen-specific CD4+ T helper type 2 (T(H)2) response and are unable to eradicate infection. Further, these animals show exacerbated production of dendritic-cell-derived interleukin-12/23p40 and tumour necrosis factor-alpha, increased levels of CD4+ T-cell-derived interferon-gamma and interleukin-17, and develop severe intestinal inflammation. Blockade of proinflammatory cytokines during Trichuris infection ablates the requirement for IKK-beta in IECs to promote CD4+ T(H)2 cell-dependent immunity, identifying an essential function for IECs in tissue-specific conditioning of dendritic cells and limiting type 1 cytokine production in the GI tract. These results indicate that the balance of IKK-beta-dependent gene expression in the intestinal epithelium is crucial in intestinal immune homeostasis by promoting mucosal immunity and limiting chronic inflammation.
Asunto(s)
Células Epiteliales/enzimología , Regulación Enzimológica de la Expresión Génica , Homeostasis , Quinasa I-kappa B/metabolismo , Intestinos/inmunología , Animales , Linfocitos T CD4-Positivos/inmunología , Citocinas/deficiencia , Citocinas/inmunología , Células Dendríticas/inmunología , Células Epiteliales/metabolismo , Quinasa I-kappa B/genética , Inmunidad Mucosa/inmunología , Interferón gamma/inmunología , Interleucina-17/inmunología , Intestinos/citología , Intestinos/parasitología , Ratones , FN-kappa B/metabolismo , Trichuris/inmunología , Trichuris/fisiología , Linfopoyetina del Estroma TímicoRESUMEN
Exopolysaccharide (EPS), a bioproduct of lactic acid bacteria (LAB), has various health-promoting biological activities that may be beneficial for cancer therapy. This in vivo and in vitro study aimed to elucidate the anti-colorectal cancer (CRC) capacity of a homopolysaccharide EPS obtained from Weissella confusa J4-1 (EPSJ4-1) isolated from the faeces of healthy infants. We confirmed that EPSJ4-1 contained glucose and effectively suppressed the proliferation, migration, and invasion of CRC cells. EPSJ4-1 treatment significantly retarded the growth of HT-29 tumour xenografts without causing cytotoxicity to normal organs. EPSJ4-1 exerts an inhibitory effect on cell proliferation by inducing G0/G1 phase cell cycle arrest in CRC cells. Furthermore, EPSJ4-1 upregulated p21 levels and downregulated mutant p53 and cyclin kinase 2 levels. This is the first study to demonstrate the antitumour effects of EPS from W. confusa on CRC via cell cycle arrest and inhibition of cell migration and invasion, suggesting that EPSJ4-1 has the potential to be developed as a nutraceutical or pharmaceutical drug to prevent and treat CRC.
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Neoplasias Colorrectales , Weissella , Lactante , Humanos , Puntos de Control del Ciclo Celular , Weissella/metabolismo , Proliferación Celular , Neoplasias Colorrectales/metabolismo , Ciclo CelularRESUMEN
Injectable functional biomaterials have made significant progress in cardiac regenerative. In addition, how to adjust the abominable infarction microenvironment and introduce therapeutic stem cells to improve the healing effect has become a hotspot. Herein, injectable stem cell vector is prepared by combining natural alginate hydrogel and Au@Pt nanoparticles (Au@Pt/Alg hydrogel) to encapsulate brown adipose stem cells (BASCs). Au@Pt nanoparticles with both antioxidative and conductive properties could effectively eliminate reactive oxygen species, enhance the frequency of action potential release of cardiomyocytes, and further reduce the inflammatory factors of macrophage in vitro. The Au@Pt/Alg hydrogel enhances the antioxidant, differentiation, and paracrine capability of BASCs. The effect of BASCs loaded Au@Pt/Alg hydrogel is evaluated in a rat myocardial infarction (MI) model. The antioxidant, anti-inflammatory, and heart electrical integration are showed in the MI model. More interestingly, Au@Pt/Alg hydrogel can effectively maintain the paracrine efficiency and pro-angiogenesis effects of BASCs in the infarcted area. This study led us to recognize the great value of Au@Pt/Alg hydrogels for their ability to actively regulate the microenvironment and carry stem cells for MI treatment.
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Infarto del Miocardio , Nanopartículas , Ratas , Animales , Hidrogeles/farmacología , Hidrogeles/uso terapéutico , Antioxidantes/farmacología , Antioxidantes/uso terapéutico , Miocitos Cardíacos , Células MadreRESUMEN
Exopolysaccharide (EPS) from Weissella cibaria has been devoted to the study of food industry. However, the anticancer activity of W. cibaria derived EPS has not yet been investigated. In this study, we obtained the EPS from W. cibaria D-2 isolated from the feces of healthy infants and found that D-2-EPS, a homopolysaccharide with porous web like structure, could effectively inhibit the proliferation, migration, invasion and induce cell cycle arrest in G0/G1 phase of colorectal cancer (CRC) cells. In HT-29 tumor xenografts, D-2-EPS significantly retarded tumor growth without obvious cytotoxicity to normal organs. Furthermore, we revealed that D-2-EPS promoted the apoptosis of CRC cells by increasing the levels of Fas, FasL and activating Caspase-8/Caspase-3, indicating that D-2-EPS might induce apoptosis through the extrinsic Fas/FasL pathway. Taken together, the D-2-EPS has the potential to be developed as a nutraceutical or drug to prevent and treat colorectal cancer.
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Neoplasias Colorrectales , Weissella , Lactante , Humanos , Polisacáridos Bacterianos/metabolismo , Weissella/metabolismo , Apoptosis , Neoplasias Colorrectales/tratamiento farmacológicoRESUMEN
The plateau pika, a typical hypoxia-tolerant mammal lives 3000-5000 m above sea level on the Qinghai-Tibet Plateau, has acquired many physiological and morphological characteristics and strategies in its adaptation to sustained, high-altitude hypoxia. Blunted hypoxic pulmonary vasoconstriction is one such strategy, but the genes involved in this strategy have not been elucidated. Here, we investigated the genes involved and their expression profiles in the lung transcriptome of plateau pikas subjected to different hypoxic conditions (using low-pressure oxygen cabins). A slight, right ventricular hypertrophy was observed in pikas of the control group (altitude: 3200 m) vs. those exposed to 5000 m altitude conditions for one week. Our assembly identified 67,774 genes; compared with their expression in the control animals, 866 and 8364 genes were co-upregulated and co-downregulated, respectively, in pikas subjected to 5000 m altitude conditions for 1 and 4 w. We elucidated pathways that were associated with pulmonary vascular arterial pressure, including vascular smooth muscle contraction, HIF-1 signalling, calcium signalling, cGMP-PKG signalling, and PI3K-Akt signalling based on the differentially expressed genes; the top-100 pathway enrichments were found between the control group and the group exposed to 5000 m altitude conditions for 4 w. The mRNA levels of 18 candidate gene showed that more than 83% of genes were expressed and the number of transcriptome The up-regulated genes were EPAS1, Hbα, iNOS, CX40, CD31, PPM1B, HIF-1α, MYLK, Pcdh12, Surfactant protein B, the down-regulated genes were RYR2, vWF, RASA1, CLASRP, HIF-3α. Our transcriptome data are a valuable resource for future genomic studies on plateau pika.
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Lagomorpha , Fosfatidilinositol 3-Quinasas , Animales , Perfilación de la Expresión Génica , Hipoxia/genética , Hipoxia/metabolismo , Lagomorpha/genética , Lagomorpha/metabolismo , Pulmón/metabolismo , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/metabolismoRESUMEN
Probiotic-based therapy for ulcerative colitis (UC) is a novel and promising approach that has gained much popularity in recent years. However, probiotics may be easily captured and destroyed by the harsh in vivo environment, which limits their application prospects to a large extent. This work introduces a versatile facile approach for decorating individual probiotics with nanozyme coatings, named Pt-Lipid@EcN. A bimolecular lipid coating is deposited on the surface of probiotics used in the oral treatment of UC using simple self-assembly with a liposome under cytocompatible conditions, and it acts as armor to effectively protect the probiotics from strong digestive acids and enzymes. The obtained results indicated that the liposome-coated Escherichia coli Nissle (EcN) 1917 could significantly improve the colonization rate of the microorganisms in the intestinal tract. We also explored the specific mechanism of Pt-Lipid@EcN to improve the behavior of murine UC models, including reduction of inflammatory effects and histological injury, and regulation of epithelial barrier homeostasis in the intestine. The nanozyme-shielded probiotic exhibited enhanced anti-inflammatory ability in vivo, introducing novel strategies for the application of nanozyme biomedicine in the treatment of colonic inflammatory diseases.
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Colitis Ulcerosa , Probióticos , Animales , Colitis Ulcerosa/tratamiento farmacológico , Escherichia coli/fisiología , Intestinos , Lípidos , Liposomas , Ratones , Probióticos/uso terapéuticoRESUMEN
IL-31 is a recently identified cytokine made predominantly by CD4(+) Th2 cells and its receptor, IL-31R, is expressed by a number of cell types including monocytes, epithelial cells, and T cells. Originally identified as a potential mediator of inflammation in the skin, we recently reported a novel function for endogenous IL-31R interactions in limiting type 2 inflammation in the lung. However, whether IL-31-IL-31R interactions regulate immunity or inflammation at other mucosal sites, such as the gut, is unknown. In this study, we report a regulatory role for IL-31-IL-31R interactions in the intestine following infection with the gastrointestinal helminth Trichuris muris, immunity to which is critically dependent on CD4(+) Th2 cells that produce IL-4 and IL-13. IL-31Ralpha was constitutively expressed in the colon and exposure to Trichuris induced the expression of IL-31 in CD4(+) T cells. In response to Trichuris infection, IL-31Ralpha(-/-) mice exhibited increased Th2 cytokine responses in the mesenteric lymph nodes and elevated serum IgE and IgG1 levels compared with wild type mice. IL-31Ralpha(-/-) mice also displayed enhanced goblet cell hyperplasia and a marked increase in secretion of goblet cell-derived resistin-like molecule beta into the intestinal lumen. Consistent with their exacerbated type 2 inflammatory responses, IL-31Ralpha(-/-) mice exhibited accelerated expulsion of Trichuris with significantly decreased worm burdens compared with their wild type counterparts early following infection. Collectively, these data provide the first evidence of a function for IL-31-IL-31R interactions in limiting the magnitude of type 2 inflammatory responses within the intestine.
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Interleucinas/inmunología , Parasitosis Intestinales/inmunología , Receptores de Interleucina/inmunología , Células Th2/inmunología , Tricuriasis/inmunología , Animales , Linfocitos B/inmunología , Linfocitos B/metabolismo , Western Blotting , Proliferación Celular , Citocinas/biosíntesis , Citocinas/inmunología , Ensayo de Inmunoadsorción Enzimática , Citometría de Flujo , Técnica del Anticuerpo Fluorescente , Células Caliciformes/inmunología , Células Caliciformes/metabolismo , Inmunoglobulina E/sangre , Inmunoglobulina E/inmunología , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Interleucinas/metabolismo , Parasitosis Intestinales/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores de Interleucina/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Células Th2/metabolismo , Tricuriasis/metabolismoRESUMEN
IL-27 limits CD4(+) T(H)17 cell development in vitro and during inflammatory responses in the CNS. However, whether IL-27-IL-27R interactions regulate the homeostasis or function of CD4(+) T cell populations in the intestine is unknown. To test this, we examined CD4(+) T cell populations in the intestine of wild-type and IL-27R(-/-) mice. Naive IL-27R(-/-) mice exhibited a selective decrease in the frequency of IFN-gamma producing CD4(+) T(H)1 cells and an increase in the frequency of T(H)17 cells in gut-associated lymphoid tissues. Associated with elevated expression of IL-17A, IL-27R(-/-) mice exhibited earlier onset and significantly increased severity of clinical disease compared with wild-type controls in a murine model of intestinal inflammation. Rag(-/-)/IL-27R(-/-) mice were also more susceptible than Rag(-/-) mice to development of dextran sodium sulfate-induced intestinal inflammation, indicating an additional role for IL-27-IL-27R in the regulation of innate immune cell function. Consistent with this, IL-27 inhibited proinflammatory cytokine production by activated neutrophils. Collectively, these data identify a role for IL-27-IL-27R interaction in controlling the homeostasis of the intestinal T cell pool and in limiting intestinal inflammation through regulation of innate and adaptive immune cell function.
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Linfocitos T CD4-Positivos/patología , Colitis/inmunología , Homeostasis/inmunología , Interleucinas/fisiología , Animales , Colitis/patología , Modelos Animales de Enfermedad , Inmunidad , Inflamación/inmunología , Interleucina-17 , Interleucinas/inmunología , Intestinos/inmunología , Intestinos/patología , Recuento de Linfocitos , Ratones , Receptores de Interleucina , Linfocitos T Colaboradores-Inductores/patologíaRESUMEN
In this study, polyamide and MCI GEL® CHP20P were employed as stationary phases in medium pressure chromatography (MPC) for the efficient preparative separation of bergenin from Saxifraga atrata. Ethanol-water, methanol-water, and acetonitrile-water mobile phases all showed good enrichment capacity for bergenin fraction when polyamide was used as a stationary phase. After 5 cycles of polyamide MPC using acetonitrile/water, 1.2 g of bergenin fraction was isolated from 180 g Saxifraga atrata herb. Further purification of this fraction was conducted using MCI GEL® CHP20P styrene-divinylbenzene beads. The bergenin fraction was separated into two fractions, and after three runs of MPC, 714.2 mg of bergenin with purity above 99% was obtained. The results demonstrate that the combination of polyamide and styrene-divinylbenzene MPC can be utilized for preparative isolation of compounds from natural products with high yield and purity.
Asunto(s)
Benzopiranos/aislamiento & purificación , Cromatografía Liquida/métodos , Nylons/química , Saxifragaceae/química , Estirenos/química , Benzopiranos/análisis , Benzopiranos/química , Cromatografía Liquida/instrumentación , Geles/química , Compuestos de Vinilo/químicaRESUMEN
Traditional Tibetan medicine (TTM) is a valuable source of novel therapeutic lead molecules inspired by natural products (NPs). The health benefits of Saxifraga atrata are well documented in TTM, but reports on its chemical composition are limited, most likely due to the complicated purification process. Herein, target separation and identification of 4 main radical scavenging compounds from the methanolic extract of S. atrata was were performed using medium- and high-pressure liquid chromatography coupled with online HPLC-DPPH detection. The sample was pretreated using medium pressure liquid chromatography with MCI GELâ CHP20P styrene-divinylbenzene beads as a stationary phase, yielding 1.4 g of the target DPPH inhibitors (Fr4, 11.9% recovery). The compounds were further purified and isolated using HPLC on RP-C18 (ReproSil-Pur C18 AQ) followed by HILIC (Click XIon) column separation, resulting in 2.8 mg of fraction Fr4-1-1, 6.8 mg of fraction Fr4-2, 244.9 mg of the Fr4-3-1 sample, and 38.3 mg of Fr4-4-1. The structure and purity of the target compounds were determined, and four compounds (ethyl gallate, 11-O-galloylbergenin, rutin and isoquercitrin) were isolated with >95% purity. The developed methodology is efficient for targeted isolation of high-purity radical scavengers from NP extracts and could be used for rapid identification and isolation of DPPH inhibitors from various NPs.
Asunto(s)
Compuestos de Bifenilo/análisis , Técnicas de Química Analítica/métodos , Cromatografía Líquida de Alta Presión , Picratos/análisis , Extractos Vegetales/aislamiento & purificación , Saxifragaceae/química , Antioxidantes/análisis , Compuestos de Bifenilo/antagonistas & inhibidores , Picratos/antagonistas & inhibidores , Extractos Vegetales/químicaRESUMEN
The secreted goblet cell-derived protein resistin-like molecule beta (RELMbeta) has been implicated in divergent functions, including a direct effector function against parasitic helminths and a pathogenic function in promoting inflammation in models of colitis and ileitis. However, whether RELMbeta influences CD4(+) T cell responses in the intestine is unknown. Using a natural model of intestinal inflammation induced by chronic infection with gastrointestinal helminth Trichuris muris, we identify dual functions for RELMbeta in augmenting CD4(+) Th1 cell responses and promoting infection-induced intestinal inflammation. Following exposure to low-dose Trichuris, wild-type C57BL/6 mice exhibit persistent infection associated with robust IFN-gamma production and intestinal inflammation. In contrast, infected RELMbeta(-/-) mice exhibited a significantly reduced expression of parasite-specific CD4(+) T cell-derived IFN-gamma and TNF-alpha and failed to develop Trichuris-induced intestinal inflammation. In in vitro T cell differentiation assays, recombinant RELMbeta activated macrophages to express MHC class II and secrete IL-12/23p40 and enhanced their ability to mediate Ag-specific IFN-gamma expression in CD4(+) T cells. Taken together, these data suggest that goblet cell-macrophage cross-talk, mediated in part by RELMbeta, can promote adaptive CD4(+) T cell responses and chronic inflammation following intestinal helminth infection.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Células Caliciformes/inmunología , Hormonas Ectópicas/fisiología , Mediadores de Inflamación/fisiología , Interferón gamma/biosíntesis , Parasitosis Intestinales/inmunología , Parasitosis Intestinales/patología , Tricuriasis/inmunología , Enfermedad Aguda , Adyuvantes Inmunológicos/fisiología , Animales , Linfocitos T CD4-Positivos/citología , Linfocitos T CD4-Positivos/metabolismo , Comunicación Celular/inmunología , Enfermedad Crónica , Células Caliciformes/metabolismo , Hormonas Ectópicas/genética , Péptidos y Proteínas de Señalización Intercelular , Parasitosis Intestinales/metabolismo , Macrófagos/inmunología , Macrófagos/patología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Resistina/genética , Resistina/fisiología , Tricuriasis/metabolismo , Tricuriasis/patología , Trichuris/inmunologíaRESUMEN
The dysfunction of the intestinal epithelial barrier contributes to local or systemic infection and inflammation. Some lactic acid bacteria (LAB) strains had been shown to improve the conditions of barrier function and, for this reason, are recognized as probiotics. Weissella cibaria, a species belonging to the LAB group, is known to promote several health benefits. However, the role of W. cibaria in regulating the integrity of the intestinal epithelial barrier has not yet been investigated. In this study, W. cibaria MW01 was isolated from Chinese sauerkraut and was selected based on its functional features, such as gastric juice and bile salt tolerance, besides antagonistic activity against pathogenic bacteria. In a cellular model of the intestinal barrier, it was observed that W. cibaria was able to adhere more efficiently than Lactobacillus rhamnosus GG in Caco-2 cells. Moreover, the LPS-induced inflammation in Caco-2 cells was attenuated by the treatment with W. cibaria MW01, which reduced the synthesis of TNF-α, IL-6, and IL-8. In addition, it was noted that the treatment with W. cibaria MW01 recovered the integrity of the Caco-2 cell monolayer exposed to LPS. Furthermore, W. cibaria MW01 significantly alleviated LPS-induced downregulation of tight junction proteins (TJP) (claudin, occludin, and tight junction protein-1). Mechanistically, W. cibaria MW01 inhibited the translocation of NF-κB to the nucleus and deactivated the MLCK-pMLC pathway during LPS exposure. Thus, W. cibaria MW01, as a potential probiotic, can protect intestinal epithelial barrier function by regulating inflammation and expression of TJP via the NF-κB-mediated MLCK-pMLC pathway.