Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 55
Filtrar
1.
Water Res ; 251: 121091, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38244299

RESUMEN

Ammonia retention and recovery from high-nitrogenous wastewater are new concepts being used for nitrogen management. A microaerophilic activated sludge system was developed to convert organic nitrogen into ammonia and retain it for its recovery; however, the settleability of activated sludge remains a challenge. Therefore, this study proposed an aerobic granular sludge system as a potential solution. Two types of sequencing batch reactors-airlift and upflow reactors-were operated to investigate the feasibility of fast granule formation, the performance of organic carbon removal and ammonia retention, and the dynamics of microbial community composition. The operation fed with industrial fermentation wastewater demonstrated that the airlift reactor ensured a more rapid granule formation than the upflow reactor because of the high shear force, and it maintained a superior ammonia retention stability of approximately 85 %. Throughout the operational period, changes in hydraulic retention time (HRT), settling time, and exchange ratio altered the granular particle sizes and microbial community compositions. Rhodocyclaceae were replaced with Comamonadaceae, Methylophilaceae, Xanthomonadaceae, and Chitinophagaceae as core taxa instrumental in granulation, likely because of their extracellular polymeric substance secretion. As the granulation process progressed, a significant decrease in the relative abundances of nitrifying bacteria-Nitrospiraceae and Nitrosomonadaceae-was observed. The reduction of settling time and HRT enhanced granulation and inhibited the activity of nitrifying bacteria. The success in granulation for ammonia conversion and retention in this study accelerates the paradigm shift from ammonia removal to ammonia recovery from industrial fermentation wastewater.


Asunto(s)
Aguas del Alcantarillado , Aguas Residuales , Aguas del Alcantarillado/microbiología , Amoníaco , Fermentación , Carbono , Matriz Extracelular de Sustancias Poliméricas/química , Eliminación de Residuos Líquidos , Reactores Biológicos/microbiología , Bacterias , Aerobiosis , Nitrógeno/análisis
2.
Environ Sci Technol ; 57(37): 13874-13886, 2023 09 19.
Artículo en Inglés | MEDLINE | ID: mdl-37676844

RESUMEN

A transition to ammonia recovery from wastewater has started; however, a technology for sustainable nitrogen retention in the form of ammonia and organic carbon removal is still in development. This study validated a microaerophilic activated sludge (MAS) system to efficiently retain ammonia from high-strength nitrogenous wastewater. The MAS is based on conventional activated sludge (CAS) with aerobic and settling compartments. Low dissolved oxygen (DO) concentrations (<0.2 mg/L) and short solids retention times (SRTs) (<5 days) eliminated nitrifying bacteria. The two parallel MASs were successfully operated for 300 days and had ammonia retention of 101.7 ± 24.9% and organic carbon removal of 85.5 ± 8.9%. The MASs mitigated N2O emissions with an emission factor of <0.23%, much lower than the default value of CAS (1.6%). A short-term step-change test demonstrated that N2O indicated the initiation of nitrification and the completion of denitrification in the MAS. The parallel MASs had comparable microbial diversity, promoting organic carbon oxidation while inhibiting ammonia-oxidizing microorganisms (AOMs), as revealed by 16S rRNA gene amplicon sequencing, the quantitative polymerase chain reaction of functional genes, and fluorescence in situ hybridization of ß-proteobacteria AOB. The microbial analyses also uncovered that filamentous bacteria were positively correlated with effluent turbidity. Together, controlling DO and SRT achieved organic carbon removal and successful ammonia retention, mainly by suppressing AOM activity. This process represents a new nitrogen management paradigm.


Asunto(s)
Microbiota , Aguas del Alcantarillado , Aguas Residuales , Amoníaco , Hibridación Fluorescente in Situ , ARN Ribosómico 16S , Carbono , Nitrógeno
3.
ACS Omega ; 7(7): 6238-6247, 2022 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-35224386

RESUMEN

A one-step preparation of alginate-stabilized gold nanoparticles (Au NPs) using the microwave-induced plasma-in-liquid process (MWPLP) was reported. Effects of alginate with various concentrations on the preparation and properties of the synthesized Au NPs, including reaction rate, morphology, size, and optical absorption property, were studied. The introduction of alginate (1) accelerated the reaction rate, (2) prevented aggregation and precipitation due to long time discharge in MWPLP, and (3) provided long-term colloidal stability. An abnormal size change (from large to small) of Au NPs during particle growth, which was opposite to the typical change in bottom-up chemical reduction, was observed and a possible mechanism was proposed based on the dynamical and thermodynamical instability of particles during growth. The strategy of drying and redispersion of Au NPs in alginate solution was also studied. The drying and redispersion process had an imperceptible effect on the Au NPs. As a consequence, this strategy might be an effective technique for the long-term storage of Au NPs and other metal NPs. The alginate-stabilized Au NPs without the addition of toxic reducing or stabilizing agents can be appropriate to biomedical applications.

4.
Diabetes ; 71(3): 470-482, 2022 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-35040474

RESUMEN

We previously showed that treating NOD mice with an agonistic monoclonal anti-TLR4/MD2 antibody (TLR4-Ab) reversed acute type 1 diabetes (T1D). Here, we show that TLR4-Ab reverses T1D by induction of myeloid-derived suppressor cells (MDSCs). Unbiased gene expression analysis after TLR4-Ab treatment demonstrated upregulation of genes associated with CD11b+Ly6G+ myeloid cells and downregulation of T-cell genes. Further RNA sequencing of purified, TLR4-Ab-treated CD11b+ cells showed significant upregulation of genes associated with bone marrow-derived CD11b+ cells and innate immune system genes. TLR4-Ab significantly increased percentages and numbers of CD11b+ cells. TLR4-Ab-induced CD11b+ cells, derived ex vivo from TLR4-Ab-treated mice, suppress T cells, and TLR4-Ab-conditioned bone marrow cells suppress acute T1D when transferred into acutely diabetic mice. Thus, the TLR4-Ab-induced CD11b+ cells, by the currently accepted definition, are MDSCs able to reverse T1D. To understand the TLR4-Ab mechanism, we compared TLR4-Ab with TLR4 agonist lipopolysaccharide (LPS), which cannot reverse T1D. TLR4-Ab remains sequestered at least 48 times longer than LPS within early endosomes, alters TLR4 signaling, and downregulates inflammatory genes and proteins, including nuclear factor-κB. TLR4-Ab in the endosome, therefore, induces a sustained, attenuated inflammatory response, providing an ideal "second signal" for the activation/maturation of MDSCs that can reverse acute T1D.


Asunto(s)
Anticuerpos Monoclonales/metabolismo , Diabetes Mellitus Tipo 1/tratamiento farmacológico , Endosomas/metabolismo , Células Supresoras de Origen Mieloide/efectos de los fármacos , Receptor Toll-Like 4/inmunología , Animales , Anticuerpos Monoclonales/farmacología , Anticuerpos Monoclonales/uso terapéutico , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/inmunología , Antígeno CD11b/análisis , Diabetes Mellitus Tipo 1/inmunología , Femenino , Regulación de la Expresión Génica/inmunología , Ratones , Ratones Endogámicos NOD , Células Supresoras de Origen Mieloide/inmunología , Células Supresoras de Origen Mieloide/fisiología
5.
Int Immunol ; 32(12): 785-798, 2020 11 23.
Artículo en Inglés | MEDLINE | ID: mdl-32840578

RESUMEN

Toll-like receptors (TLRs) impact myeloid cell responsiveness to environmental cues such as pathogen components and metabolites. Although TLR protein expression in monocytes and tissue macrophages is thought to be optimized for microenvironments in each tissue, a comprehensive study has not been reported. We here examined protein expression of endogenous TLRs in tissue-resident myeloid cells. Neutrophils in peripheral blood, spleen, liver and lung expressed TLR2, TLR4 and TLR5 in all tissues. Ly6C+ MHC II‒ classical monocytes mature into Ly6C‒ MHC II+ monocyte-derived dendritic cells (moDCs) or Ly6C‒ MHC II‒ patrolling monocytes. These subsets were found in all the tissues studied. TLR2 and TLR4 were displayed on all of these subsets, regardless of location. In contrast, expression of endosomal TLRs did vary with tissues and subsets. moDCs expressed TLR9, but much less TLR7. In contrast, TLR7, not TLR3 or TLR9, was highly expressed in classical and patrolling monocytes. Tissue macrophages such as red pulp macrophages in the spleen, Kupffer cells in the liver, microglia in the brain, alveolar macrophages in the lung and adipose tissue macrophages all expressed TLR2, TLR4 and TLR3. TLR7 was also expressed in these tissue macrophages except Kupffer cells in the liver. TLR9 expression in tissue macrophages was much lower or hard to detect. These results suggest that expression of endosomal TLRs in myeloid cells is influenced by their differentiation status and tissue-specific microenvironments.


Asunto(s)
Endosomas/inmunología , Macrófagos/inmunología , Monocitos/inmunología , Receptores Toll-Like/inmunología , Animales , Células Cultivadas , Ratones , Receptores Toll-Like/genética
6.
Rapid Commun Mass Spectrom ; 34 Suppl 1: e8551, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31412144

RESUMEN

RATIONALE: Hepatocellular carcinoma (HCC) is a highly malignant disease for which the development of prospective or prognostic biomarkers is urgently required. Although metabolomics is widely used for biomarker discovery, there are some bottlenecks regarding the comprehensiveness of detected features, reproducibility of methods, and identification of metabolites. In addition, information on localization of metabolites in tumor tissue is needed for functional analysis. Here, we developed a wide-polarity global metabolomics (G-Met) method, identified HCC biomarkers in human liver samples by high-definition mass spectrometry (HDMS), and demonstrated localization in cryosections using desorption electrospray ionization MS imaging (DESI-MSI) analysis. METHODS: Metabolic profiling of tumor (n = 38) and nontumor (n = 72) regions in human livers of HCC was performed by an ultrahigh-performance liquid chromatography quadrupole time-of-flight MS (UHPLC/QTOFMS) instrument equipped with a mixed-mode column. The HCC biomarker candidates were extracted by multivariate analyses and identified by matching values of the collision cross section and their fragment ions on the mass spectra obtained by HDMS. Cryosections of HCC livers, which included both tumor and nontumor regions, were analyzed by DESI-MSI. RESULTS: From the multivariate analysis, m/z 904.83 and m/z 874.79 were significantly high and low, respectively, in tumor samples and were identified as triglyceride (TG) 16:0/18:1(9Z)/20:1(11Z) and TG 16:0/18:1(9Z)/18:2(9Z,12Z) using the synthetic compounds. The TGs were clearly localized in the tumor or nontumor areas of the cryosection. CONCLUSIONS: Novel biomarkers for HCC were identified by a comprehensive and reproducible G-Met method with HDMS using a mixed-mode column. The combination analysis of UHPLC/QTOFMS and DESI-MSI revealed that the different molecular species of TGs were associated with tumor distribution and were useful for characterizing the progression of tumor cells and discovering prospective biomarkers.


Asunto(s)
Carcinoma Hepatocelular/diagnóstico , Neoplasias Hepáticas/diagnóstico , Hígado/patología , Biomarcadores de Tumor/análisis , Biomarcadores de Tumor/metabolismo , Carcinoma Hepatocelular/metabolismo , Cromatografía Líquida de Alta Presión , Humanos , Hígado/metabolismo , Neoplasias Hepáticas/metabolismo , Metaboloma , Espectrometría de Masa por Ionización de Electrospray , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
7.
Sci Rep ; 9(1): 19075, 2019 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-31836785

RESUMEN

Carboxyl-containing metabolites, such as bile acids and fatty acids, have many important functions and microbiota is involved in the production of them. In the previous study, we found that the chronic kidney disease (CKD) model mice raised under germ-free conditions provided more severe renal damage than the mice with commensal microbiota. However, the precise influence by the microbiome and carboxyl-containing metabolites to the renal functions is unknown. In this study, we aimed to develop a novel chemical isotope labeling-LC-MS/MS method using the 2-picolylamine and its isotopologue and applied the analysis of effects of microbiome and CKD pathophysiology. The developed semi-quantitative method provided the high accuracy not inferior to the absolute quantification. By comparing of four groups of mice, we found that both microbiota and renal function can alter the composition and level of these metabolites in both plasma and intestine. In particular, the intestinal level of indole-3-acetic acid, short-chain fatty acids and n-3 type of polyunsaturated fatty acid, which play important roles in the endothelial barrier function, were significantly lower in germ-free conditions mice with renal failure. Accordingly, it is suggested these metabolites might have a renoprotective effect on CKD by suppressing epithelial barrier disruption.


Asunto(s)
Aminas/química , Microbioma Gastrointestinal , Marcaje Isotópico , Metaboloma , Insuficiencia Renal Crónica/microbiología , Espectrometría de Masas en Tándem , Aminas/síntesis química , Animales , Ácidos y Sales Biliares/metabolismo , Ciego/metabolismo , Cromatografía Liquida , Heces/microbiología , Indicadores y Reactivos , Redes y Vías Metabólicas , Ratones , Organismos Libres de Patógenos Específicos
8.
Immunology ; 158(2): 136-149, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31515801

RESUMEN

Immune-checkpoint blockade antibodies have been approved for the treatment of cancer. However, poorly immunogenic tumours are less responsive to such therapies. Agonistic anti-Toll-like receptor 4 (TLR4) monoclonal antibodies (mAbs) activate only cell-surface TLR4; in contrast, lipopolysaccharide (LPS) activates both TLR4 and intracellular inflammatory caspases. In this study, we investigated the adjuvant activity of an anti-TLR4 mAb in T-cell-mediated antitumour immunity. The anti-TLR4 mAb induced the activation of antigen-specific T-cells in adoptive transfer studies. The growth of ovalbumin (OVA)-expressing tumours was significantly suppressed by administration of OVA and the anti-TLR4 mAb in combination, but not individually. The antitumour effect of anti-PD-1 mAb was enhanced in mice administered with OVA plus the anti-TLR4 mAb. The OVA-specific IFN-γ-producing CD8 T-cells were induced by administration of OVA and the anti-TLR4 mAb. The suppression of tumour growth was diminished by depletion of CD8, but not CD4, T-cells. The inflammatory response to the anti-TLR4 mAb was of significantly lesser magnitude than that to LPS, as assessed by NF-κB activation and production of TNF-α, IL-6 and IL-1ß. Administration of LPS (at a dose that elicited levels of proinflammatory cytokines comparable to those by the anti-TLR4 mAb) plus OVA induced no or less-marked activation of OVA-specific T-cells and failed to suppress tumour growth in mice. In conclusion, the agonistic anti-TLR4 mAb induces potent CD8 T-cell-dependent antitumour immunity and an inflammatory response of lesser magnitude than does LPS. The agonistic anti-TLR4 mAb has potential as an adjuvant for use in vaccines against cancer.


Asunto(s)
Adyuvantes Inmunológicos/farmacología , Anticuerpos Monoclonales/farmacología , Antineoplásicos Inmunológicos/farmacología , Melanoma Experimental/terapia , Neoplasias Cutáneas/terapia , Receptor Toll-Like 4/antagonistas & inhibidores , Animales , Linfocitos T CD8-positivos/efectos de los fármacos , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/patología , Inmunización , Inmunoterapia/métodos , Interferón gamma/genética , Interferón gamma/inmunología , Interleucina-1beta/genética , Interleucina-1beta/inmunología , Interleucina-6/genética , Interleucina-6/inmunología , Lipopolisacáridos/farmacología , Activación de Linfocitos/efectos de los fármacos , Macrófagos/efectos de los fármacos , Macrófagos/inmunología , Melanoma Experimental/genética , Melanoma Experimental/inmunología , Melanoma Experimental/patología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , FN-kappa B/genética , FN-kappa B/inmunología , Ovalbúmina/administración & dosificación , Cultivo Primario de Células , Receptor de Muerte Celular Programada 1/genética , Receptor de Muerte Celular Programada 1/inmunología , Neoplasias Cutáneas/genética , Neoplasias Cutáneas/inmunología , Neoplasias Cutáneas/patología , Células TH1/efectos de los fármacos , Células TH1/inmunología , Células TH1/patología , Receptor Toll-Like 4/genética , Receptor Toll-Like 4/inmunología , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/inmunología
9.
Nat Commun ; 10(1): 1835, 2019 04 23.
Artículo en Inglés | MEDLINE | ID: mdl-31015435

RESUMEN

Diabetic kidney disease is a major cause of renal failure that urgently necessitates a breakthrough in disease management. Here we show using untargeted metabolomics that levels of phenyl sulfate, a gut microbiota-derived metabolite, increase with the progression of diabetes in rats overexpressing human uremic toxin transporter SLCO4C1 in the kidney, and are decreased in rats with limited proteinuria. In experimental models of diabetes, phenyl sulfate administration induces albuminuria and podocyte damage. In a diabetic patient cohort, phenyl sulfate levels significantly correlate with basal and predicted 2-year progression of albuminuria in patients with microalbuminuria. Inhibition of tyrosine phenol-lyase, a bacterial enzyme responsible for the synthesis of phenol from dietary tyrosine before it is metabolized into phenyl sulfate in the liver, reduces albuminuria in diabetic mice. Together, our results suggest that phenyl sulfate contributes to albuminuria and could be used as a disease marker and future therapeutic target in diabetic kidney disease.


Asunto(s)
Albuminuria/etiología , Diabetes Mellitus Experimental/complicaciones , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 2/complicaciones , Nefropatías Diabéticas/sangre , Microbioma Gastrointestinal/fisiología , Ésteres del Ácido Sulfúrico/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Albuminuria/sangre , Albuminuria/tratamiento farmacológico , Albuminuria/patología , Animales , Animales Modificados Genéticamente , Estudios de Cohortes , Diabetes Mellitus Experimental/sangre , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Experimental/orina , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 2/sangre , Nefropatías Diabéticas/etiología , Nefropatías Diabéticas/patología , Perros , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/uso terapéutico , Femenino , Humanos , Células de Riñón Canino Madin Darby , Masculino , Metabolómica/métodos , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Transportadores de Anión Orgánico/genética , Podocitos/metabolismo , Podocitos/patología , Ratas , Estreptozocina/toxicidad , Ésteres del Ácido Sulfúrico/sangre , Tirosina Fenol-Liasa/antagonistas & inhibidores , Tirosina Fenol-Liasa/metabolismo , Adulto Joven
10.
Eur J Immunol ; 49(4): 546-563, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30671932

RESUMEN

In sepsis, the pathology involves a shift from a proinflammatory state toward an immunosuppressive phase. We previously showed that an agonistic anti-TLR4 antibody induced long-term endotoxin tolerance and suppressed antigen-specific secondary IgG production when primed prior to immunization with antigen. These findings led us to speculate that TLR4-induced innate tolerance due to primary infection causes an immunosuppressive pathology in sepsis. Therefore, the mechanism underlying impaired antigen-specific humoral immunity by the TLR4 antibody was investigated. We showed, in a mouse model, that primary antigen-specific IgG responses were impaired in TLR4 antibody-induced tolerized mice, which was the result of reduced numbers of antigen-specific GC B cells and plasma cells. Ovalbumin-specific CD4 and CD8 T-cell responses were impaired in TLR4 antibody-injected OT-I and -II transgenic mice ex vivo. Adoptive transfer studies demonstrated suppression of OVA-specific CD4 and CD8 T-cell responses by the TLR4 antibody in vivo. The TLR4 antibody induced Gr1+ CD11b+ myeloid-derived suppressor cell (MDSC) expansion with suppression of T-cell activation. Monocytic MDSCs were more suppressive and exhibited higher expression of PD-L1 and inducible nitric oxidase compared with granulocytic MDSCs. In conclusion, immune tolerance conferred by TLR4 activation induces the expansion of monocytic MDSCs, which impairs antigen-specific T-cell priming and IgG production.


Asunto(s)
Epítopos de Linfocito T/inmunología , Activación de Linfocitos/inmunología , Linfocitos/inmunología , Linfocitos/metabolismo , Células Supresoras de Origen Mieloide/inmunología , Células Supresoras de Origen Mieloide/metabolismo , Receptor Toll-Like 4/metabolismo , Animales , Formación de Anticuerpos/inmunología , Biomarcadores , Epítopos de Linfocito B/inmunología , Tolerancia Inmunológica , Inmunización , Inmunofenotipificación , Ratones
11.
Biol Pharm Bull ; 41(8): 1170-1177, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30068866

RESUMEN

Patients with chronic kidney disease (CKD) have increased blood levels of phenyl sulfate (PS), a circulating uremic toxin. In this study, we produced anti-PS monoclonal antibodies (mAbs) and characterized their cross-reactivity to structural PS analogs. To induce PS-specific mAbs, we synthesized 4-mercaptophenyl sulfate with a sulfhydryl group at the para-position of PS and conjugated it to carrier proteins via bifunctional linkers. Using these PS conjugates as immunogens and as antigens for enzyme-linked immunosorbent assay (ELISA) screening, we produced by a hybridoma method two novel mAbs (YK33.1 and YKS19.2) that react with PS conjugates independent of carrier and linker structures. Although all of the PS analogs tested, with the exception of indoxyl sulfate, were cross-reactive to both mAbs in phosphate buffered saline (PBS), PS specificity for YKS19.2 was enhanced in human plasma and serum. YKS19.2 mAb was cross-reactive only with o-cresyl sulfate, which is absent in human blood. PS sensitivity for YKS19.2 mAb increased to an IC50 of 10.4 µg/mL when 0.1% Tween 20 was added in a primary competitive reaction. To explore potential clinical applications, we determined concentrations of PS in serum samples from 19 CKD patients by inhibition ELISA using YKS19.2 mAb and compared them to those found using an LC-MS/MS method. A good correlation was observed between each value (R2=0.825). Therefore, the unique antigen specificity of YKS19.2 mAb could be useful for prescreening of patients with accumulated PS or for comprehensive analysis of uremic toxins that have a PS-like structure.


Asunto(s)
Anticuerpos Monoclonales/inmunología , Insuficiencia Renal Crónica/sangre , Ésteres del Ácido Sulfúrico/sangre , Ésteres del Ácido Sulfúrico/inmunología , Animales , Antígenos/química , Antígenos/inmunología , Línea Celular Tumoral , Cromatografía Liquida , Ensayo de Inmunoadsorción Enzimática , Femenino , Hemocianinas/química , Hemocianinas/inmunología , Humanos , Inmunoconjugados/química , Inmunoconjugados/inmunología , Ratones Endogámicos BALB C , Ovalbúmina/química , Ovalbúmina/inmunología , Albúmina Sérica Bovina/química , Albúmina Sérica Bovina/inmunología , Ésteres del Ácido Sulfúrico/química , Espectrometría de Masas en Tándem
12.
J Biol Chem ; 293(26): 10186-10201, 2018 06 29.
Artículo en Inglés | MEDLINE | ID: mdl-29760187

RESUMEN

Toll-like receptor 4 (TLR4) is an indispensable immune receptor for lipopolysaccharide (LPS), a major component of the Gram-negative bacterial cell wall. Following LPS stimulation, TLR4 transmits the signal from the cell surface and becomes internalized in an endosome. However, the spatial regulation of TLR4 signaling is not fully understood. Here, we investigated the mechanisms of LPS-induced TLR4 internalization and clarified the roles of the extracellular LPS-binding molecules, LPS-binding protein (LBP), and glycerophosphatidylinositol-anchored protein (CD14). LPS stimulation of CD14-expressing cells induced TLR4 internalization in the presence of serum, and an inhibitory anti-LBP mAb blocked its internalization. Addition of LBP to serum-free cultures restored LPS-induced TLR4 internalization to comparable levels of serum. The secretory form of the CD14 (sCD14) induced internalization but required a much higher concentration than LBP. An inhibitory anti-sCD14 mAb was ineffective for serum-mediated internalization. LBP lacking the domain for LPS transfer to CD14 and a CD14 mutant with reduced LPS binding both attenuated TLR4 internalization. Accordingly, LBP is an essential serum molecule for TLR4 internalization, and its LPS transfer to membrane-anchored CD14 (mCD14) is a prerequisite. LBP induced the LPS-stimulated phosphorylation of TBK1, IKKϵ, and IRF3, leading to IFN-ß expression. However, LPS-stimulated late activation of NF-κB or necroptosis were not affected. Collectively, our results indicate that LBP controls LPS-induced TLR4 internalization, which induces TLR adaptor molecule 1 (TRIF)-dependent activation of the TBK1-IKKϵ-IRF3-IFN-ß pathway. In summary, we showed that LBP-mediated LPS transfer to mCD14 is required for serum-dependent TLR4 internalization and activation of the TRIF pathway.


Asunto(s)
Proteínas de Fase Aguda/metabolismo , Proteínas Portadoras/metabolismo , Quinasa I-kappa B/metabolismo , Factor 3 Regulador del Interferón/metabolismo , Receptores de Lipopolisacáridos/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Receptor Toll-Like 4/metabolismo , Humanos , Lipopolisacáridos/farmacología , Antígeno 96 de los Linfocitos/metabolismo , Fosforilación/efectos de los fármacos , Transporte de Proteínas/efectos de los fármacos
13.
Am J Physiol Renal Physiol ; 315(4): F824-F833, 2018 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-29167170

RESUMEN

Accumulation of uremic toxins, which exert deleterious effects in chronic kidney disease, is influenced by the intestinal environment; the microbiota contributes to the production of representative uremic toxins, including p-cresyl sulfate and indoxyl sulfate. Canagliflozin is a sodium-glucose cotransporter (SGLT) 2 inhibitor, and it also exerts a modest inhibitory effect on SGLT1. The inhibition of intestinal SGLT1 can influence the gastrointestinal environment. We examined the effect of canagliflozin on the accumulation of uremic toxins in chronic kidney disease using adenine-induced renal failure mice. Two-week canagliflozin (10 mg/kg po) treatment did not influence the impaired renal function; however, it significantly reduced the plasma levels of p-cresyl sulfate and indoxyl sulfate in renal failure mice (a 75% and 26% reduction, respectively, compared with the vehicle group). Additionally, canagliflozin significantly increased cecal short-chain fatty acids in the mice, suggesting the promotion of bacterial carbohydrate fermentation in the intestine. Analysis of the cecal microbiota showed that canagliflozin significantly altered microbiota composition in the renal failure mice. These results indicate that canagliflozin exerts intestinal effects that reduce the accumulation of uremic toxins including p-cresyl sulfate. Reduction of accumulated uremic toxins by canagliflozin could provide a potential therapeutic option in chronic kidney disease.


Asunto(s)
Canagliflozina/farmacología , Microbioma Gastrointestinal/efectos de los fármacos , Insuficiencia Renal Crónica/tratamiento farmacológico , Toxinas Biológicas/sangre , Animales , Modelos Animales de Enfermedad , Tracto Gastrointestinal/efectos de los fármacos , Masculino , Ratones Endogámicos C57BL , Insuficiencia Renal Crónica/sangre , Inhibidores del Cotransportador de Sodio-Glucosa 2/farmacología , Toxinas Biológicas/farmacología , Uremia/sangre , Uremia/tratamiento farmacológico
14.
Artículo en Inglés | MEDLINE | ID: mdl-29024911

RESUMEN

Column choice is crucial to the development of liquid chromatography/tandem mass spectrometry (LC-MS/MS) methods because analyte selectivity is dependent on the nature of the stationary phase. Recently, mixed-mode chromatography, which employs a combination of two or more stationary phases and solvent systems, has emerged as an alternative to multiple, complementary, single-column systems. This report describes the development and validation of a novel analytical method based on LC-MS/MS employing a reversed-phase/cation-exchange/anion-exchange tri-modal column (Scherzo SS-C18; Imtakt) for the simultaneous quantification of various uremic toxins (UTx), including creatinine, 1-methyladenosine, trimethylamine-N-oxide, indoxyl sulfate, p-cresyl sulfate, phenyl sulfate and 4-ethylphenyl sulfate. Stable isotope-labeled compounds were prepared as internal standards (ISs) for each analyte. Mobile phase optimization and appropriate gradient conditions resulted in satisfactory retention and peak resolution that could not have been attained with a single stationary phase LC system. The essential validation parameters, including intra- and inter-assay precision and accuracy, were adequate. The validated method was applied to measure serum levels of the aforementioned compounds in 19 patients with chronic kidney disease. This is the first report detailing the simultaneous quantification of these analytes using stable isotopes as ISs. Our results suggest that Scherzo SS-C18 columns will be considered breakthrough tools in the development of analytical methods for compounds that are difficult to quantify simultaneously in traditional LC systems.


Asunto(s)
Cromatografía por Intercambio Iónico/métodos , Cromatografía de Fase Inversa/métodos , Espectrometría de Masas en Tándem/métodos , Toxinas Biológicas/sangre , Humanos , Modelos Lineales , Insuficiencia Renal Crónica/sangre , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
16.
FEBS Lett ; 591(16): 2406-2416, 2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-28741733

RESUMEN

Lipopolysaccharide (LPS)-induced activation of Toll-like receptor 4 (TLR4) elicits the innate immune response and can trigger septic shock if excessive. Two antibodies (HT4 and HT52) inhibit LPS-induced human TLR4 activation via novel LPS binding-independent mechanisms. The HT52 epitope resides on leucine-rich repeat 2 (LRR2) and is a feature of many inhibitory antibodies; antigen specificity of HT4 does not reside in LRR2. Here, we identified an HT4 epitope on LRR13 located close to the TLR4 dimerization interface that plays a role in NFκB activation. HT4 and HT52 mutually enhanced TLR4 inhibition. LRR13 is a novel inhibitory epitope and may be useful for developing anti-TLR4 antibodies. Combination therapy with LRR2 and LRR13 may effectively inhibit TLR4 activation.


Asunto(s)
Secuencias de Aminoácidos , Anticuerpos Monoclonales/inmunología , Epítopos/inmunología , Receptor Toll-Like 4/química , Receptor Toll-Like 4/inmunología , Secuencia de Aminoácidos , Animales , Línea Celular , Humanos , Lipopolisacáridos/farmacología , Ratones , Multimerización de Proteína , Estructura Cuaternaria de Proteína , Receptor Toll-Like 4/metabolismo
17.
Kidney Int ; 92(3): 634-645, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28396122

RESUMEN

Gut microbiota is involved in the metabolism of uremic solutes. However, the precise influence of microbiota to the retention of uremic solutes in CKD is obscure. To clarify this, we compared adenine-induced renal failure and control mice under germ-free or specific pathogen-free (SPF) conditions, examining the metabolite profiles of plasma, feces, and urine using a capillary electrophoresis time-of-flight mass spectrometry-based approach. Mice with renal failure under germ-free conditions demonstrated significant changes in plasma metabolites. Among 183 detected solutes, plasma levels of 11 solutes, including major uremic toxins, were significantly lower in germ-free mice than in SPF mice with renal failure. These 11 solutes were considered microbiota-derived uremic solutes and included indoxyl sulfate, p-cresyl sulfate, phenyl sulfate, cholate, hippurate, dimethylglycine, γ-guanidinobutyrate, glutarate, 2-hydroxypentanoate, trimethylamine N-oxide, and phenaceturate. Metabolome profiling showed that these solutes were classified into three groups depending on their origins: completely derived from microbiota (indoxyl sulfate, p-cresyl sulfate), derived from both host and microbiota (dimethylglycine), and derived from both microbiota and dietary components (trimethylamine N-oxide). Additionally, germ-free renal failure conditions resulted in the disappearance of colonic short-chain fatty acids, decreased utilization of intestinal amino acids, and more severe renal damage compared with SPF mice with renal failure. Microbiota-derived short-chain fatty acids and efficient amino acid utilization may have a renoprotective effect, and loss of these factors may exacerbate renal damage in germ-free mice with renal failure. Thus, microbiota contributes substantially to the production of harmful uremic solutes, but conversely, growth without microbiota has harmful effects on CKD progression.


Asunto(s)
Lesión Renal Aguda/metabolismo , Microbioma Gastrointestinal/fisiología , Metaboloma , Insuficiencia Renal Crónica/metabolismo , Toxinas Biológicas/sangre , Uremia/metabolismo , Lesión Renal Aguda/sangre , Lesión Renal Aguda/inducido químicamente , Lesión Renal Aguda/orina , Adenina/toxicidad , Animales , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Electroforesis Capilar , Ácidos Grasos Volátiles/análisis , Ácidos Grasos Volátiles/metabolismo , Humanos , Riñón/patología , Espectrometría de Masas , Metabolómica/métodos , Ratones , Insuficiencia Renal Crónica/sangre , Insuficiencia Renal Crónica/patología , Insuficiencia Renal Crónica/orina , Organismos Libres de Patógenos Específicos , Toxinas Biológicas/orina , Uremia/sangre , Uremia/orina
18.
Sci Rep ; 7: 45150, 2017 03 24.
Artículo en Inglés | MEDLINE | ID: mdl-28338044

RESUMEN

Mixtures of a copper complex and copper fine particles as copper-based metal-organic decomposition (MOD) dispersions have been demonstrated to be effective for low-temperature sintering of conductive copper film. However, the copper particle size effect on decomposition process of the dispersion during heating and the effect of organic residues on the resistivity have not been studied. In this study, the decomposition process of dispersions containing mixtures of a copper complex and copper particles with various sizes was studied. The effect of organic residues on the resistivity was also studied using thermogravimetric analysis. In addition, the choice of copper salts in the copper complex was also discussed. In this work, a low-resistivity sintered copper film (7 × 10-6 Ω·m) at a temperature as low as 100 °C was achieved without using any reductive gas.

19.
ACS Omega ; 2(8): 5104-5110, 2017 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-31457785

RESUMEN

Production of oxygen-deficient tungsten oxide nanoparticles with a diameter of around 10 nm have been successfully developed using a microwave-induced plasma in liquid technique. The prepared blue-green nanoparticles exhibit strong absorption in the visible region; thus, these could be efficient visible-light photocatalysts. The high-angle annular dark-field images revealed the dislocation of tungsten, which causes oxygen deficiencies.

20.
Tohoku J Exp Med ; 240(1): 47-56, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27594509

RESUMEN

The interleukin (IL)-17 family, consisting of six homodimeric cytokines IL-17A, IL-17B, IL-17C, IL-17D, IL-17E/IL-25, and IL-17F, mediates a variety of biological activities including regulation of chemokine secretion and angiogenesis. Among the IL-17 family members, IL-17A and IL-17E/IL-25 are angiogenesis stimulators, while IL-17B and IL-17F are angiogenesis inhibitors. Recently, IL-17A/F heterodimer, comprised of the IL-17A and IL-17F subunits, was found as another member of the IL-17 cytokine family. However, to date, it has been unknown whether IL-17A/F has biological actions to affect the angiogenesis-related vascular endothelial functions. Therefore, in this study, we investigated the biological effects of IL-17A/F on the growth, migration and capillary-like tube formation of vascular endothelial cells. Recombinant IL-17A/F protein had no direct effects on the growth of human dermal microvascular endothelial cells (HMVECs), whereas, after 4-hour incubation in a modified Boyden Chemotaxicell chamber, IL-17A/F significantly induced migration of HMVECs over a wide range of doses via the phosphatidylinositol-3 kinase (PI3K) signaling pathway. We further investigated the biological effect of IL-17A/F on capillary-like tube formation using a co-culture system of human umbilical vein endothelial cells (HUVECs) and human dermal fibroblasts (HDFs), which mimicked the in vivo microenvironment. In this co-culture system, IL-17A/F significantly promoted capillary-like endothelial tube formation in a dose-dependent fashion via the PI3K and extracellular signal-regulated kinase (ERK) signaling pathways. Additionally, IL-17A/F up-regulated secretion of angiogenic growth factors such as IL-8 and growth-related oncogene (GRO)-α by HDFs. These findings identify a novel biological function for IL-17A/F as an indirect angiogenic agent.


Asunto(s)
Movimiento Celular/efectos de los fármacos , Células Endoteliales/citología , Interleucina-17/farmacología , Neovascularización Fisiológica/efectos de los fármacos , Multimerización de Proteína , Proliferación Celular/efectos de los fármacos , Quimiocinas/metabolismo , Dermis/irrigación sanguínea , Células Endoteliales/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Humanos , Microvasos/citología , Regulación hacia Arriba/efectos de los fármacos , Factor A de Crecimiento Endotelial Vascular/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...