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1.
Nat Immunol ; 23(2): 287-302, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35105987

RESUMEN

The volume-regulated anion channel (VRAC) is formed by LRRC8 proteins and is responsible for the regulatory volume decrease (RVD) after hypotonic cell swelling. Besides chloride, VRAC transports other molecules, for example, immunomodulatory cyclic dinucleotides (CDNs) including 2'3'cGAMP. Here, we identify LRRC8C as a critical component of VRAC in T cells, where its deletion abolishes VRAC currents and RVD. T cells of Lrrc8c-/- mice have increased cell cycle progression, proliferation, survival, Ca2+ influx and cytokine production-a phenotype associated with downmodulation of p53 signaling. Mechanistically, LRRC8C mediates the transport of 2'3'cGAMP in T cells, resulting in STING and p53 activation. Inhibition of STING recapitulates the phenotype of LRRC8C-deficient T cells, whereas overexpression of p53 inhibits their enhanced T cell function. Lrrc8c-/- mice have exacerbated T cell-dependent immune responses, including immunity to influenza A virus infection and experimental autoimmune encephalomyelitis. Our results identify cGAMP uptake through LRRC8C and STING-p53 signaling as a new inhibitory signaling pathway in T cells and adaptive immunity.


Asunto(s)
Aniones/metabolismo , Fosfatos de Dinucleósidos/metabolismo , Canales Iónicos/metabolismo , Proteínas de la Membrana/metabolismo , Linfocitos T/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Animales , Calcio/metabolismo , Femenino , Ratones , Ratones Endogámicos C57BL , Nucleótidos Cíclicos/metabolismo , Transducción de Señal/fisiología
2.
J Biol Chem ; 300(7): 107413, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38810698

RESUMEN

Ataxin-2 (Atx2) is a polyglutamine (polyQ) tract-containing RNA-binding protein, while its polyQ expansion may cause protein aggregation that is implicated in the pathogenesis of neurodegenerative diseases such as spinocerebellar ataxia type 2 (SCA2). However, the molecular mechanism underlying how Atx2 aggregation contributes to the proteinopathies remains elusive. Here, we investigated the influence of Atx2 aggregation on the assembly and functionality of cellular processing bodies (P-bodies) by using biochemical and fluorescence imaging approaches. We have revealed that polyQ-expanded (PQE) Atx2 sequesters the DEAD-box RNA helicase (DDX6), an essential component of P-bodies, into aggregates or puncta via some RNA sequences. The N-terminal like-Sm (LSm) domain of Atx2 (residues 82-184) and the C-terminal helicase domain of DDX6 are responsible for the interaction and specific sequestration. Moreover, sequestration of DDX6 may aggravate pre-mRNA mis-splicing, and interfere with the assembly of cellular P-bodies, releasing the endoribonuclease MARF1 that promotes mRNA decay and translational repression. Rescuing the DDX6 protein level can recover the assembly and functionality of P-bodies, preventing targeted mRNA from degradation. This study provides a line of evidence for sequestration of the P-body components and impairment of the P-body homeostasis in dysregulating RNA metabolism, which is implicated in the disease pathologies and a potential therapeutic target.


Asunto(s)
Ataxina-2 , ARN Helicasas DEAD-box , Homeostasis , Péptidos , ARN Helicasas DEAD-box/metabolismo , ARN Helicasas DEAD-box/genética , Humanos , Ataxina-2/metabolismo , Ataxina-2/genética , Péptidos/metabolismo , Péptidos/química , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas/genética , Células HEK293 , Ataxias Espinocerebelosas/metabolismo , Ataxias Espinocerebelosas/genética , Agregado de Proteínas , Empalme del ARN , Dominios Proteicos , Precursores del ARN/metabolismo , Precursores del ARN/genética
3.
Environ Sci Technol ; 58(40): 17908-17915, 2024 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-39344972

RESUMEN

Resistant bacteria have always been of research interest worldwide. In the urban water system, the increased disinfectant usage gives more chances for undesirable disinfection-resistant bacteria. As the strongest oxidative disinfectant in large-scale water treatment, ozone might select ozone-resistant bacteria (ORB), which, however, have rarely been reported and are inexplicit for their resistant mechanisms and physiological characteristics. In this study, six strains of ORB were screened from a water reclamation plant in Beijing. Three of them (O7, CR19, and O4) were more resistant to ozone than all previously reported ORB or even spores. The ozone consumption capacity of extracellular polymeric substances and cell walls was proved to be the main sources of bacterial ozone resistance, rather than intracellular antioxidant enzymes. The transcriptome results elucidated that strong ORB possessed a combined antioxidant mechanism consisting of the enhanced transcription of protein synthesis, protein export, and polysaccharide export genes (LptF, LptB, NodJ, LivK, LviG, MetQ, MetN, and GltU). This study confirmed the existence of ORB in urban water systems and brought doubts to the idea of a traditional control strategy against chlorine-resistant bacteria. A salient "trade-off" effect between the ozone resistance and propagation ability indicated the weakness and potential control approaches of ORB.


Asunto(s)
Bacterias , Ozono , Purificación del Agua , Ozono/farmacología , Bacterias/efectos de los fármacos , Desinfectantes/farmacología , Desinfección
4.
Int J Mol Sci ; 25(19)2024 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-39408766

RESUMEN

Sugarcane thrips, Fulmekiola serrata (Kobus) (Thysanoptera: Thripidae), is a common foliar pest that infests sugarcane and is found throughout tropical and subtropical countries. In this study, we obtained and analyzed the complete mitochondrial genome of F. serrata for the first time and explored the phylogenetic relationships of the higher-order elements of Thysanoptera members at the mitochondrial level. The complete mitochondrial genome of F. serrata is 16,596 bp in length and includes 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes, and 1 noncoding control region. A+T accounted for 75% of the total bases in the mitochondrial genome of F. serrata, revealing an obvious AT bias. Among the 13 PCGs, except for nad5, which had a start codon of TTG, the remaining genes had ATNs typical of insects (ATA, ATT, ATC, and ATG); nad1, nad2, nad3, and atp8 had incomplete termination codons of TA or T. The remaining nine PCGs were complete with the termination codon TAA. Of the 22 tRNA secondary structures, all were typical cloverleaf secondary structures except for trnS1, which was missing the DHU arm. Compared with the hypothetical ancestral gene arrangement of arthropods, F. serrata presented extensive gene rearrangement, with 23 translocated genes, 8 inverted genes, and 5 shuffled genes. Both maximum likelihood (ML) and Bayesian inference (BI) phylogenetic trees resulted in similar topologies: ((Thripidae + (Stenurothripidae + Aeolothripidae)) + Phlaeothripidae), with Thripidae, Aeolothripidae and Phlaeothripidae being monophyletic groups, whereas F. serrata is closely related to Thrips palmi, and the two are sister groups.


Asunto(s)
Genoma Mitocondrial , Filogenia , ARN de Transferencia , Thysanoptera , Animales , Thysanoptera/genética , Thysanoptera/clasificación , ARN de Transferencia/genética , ARN Ribosómico/genética
5.
Environ Microbiol ; 25(3): 675-688, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36527381

RESUMEN

Microbial ammonia oxidation is vital to the nitrogen cycle. A biological process, called Dirammox (direct ammonia oxidation, NH3 →NH2 OH→N2 ), has been recently identified in Alcaligenes ammonioxydans and Alcaligenes faecalis. However, its transcriptional regulatory mechanism has not yet been fully elucidated. The present study characterized a new MocR-like transcription factor DnfR that is involved in the Dirammox process in A. faecalis strain JQ135. The entire dnf cluster was composed of 10 genes and transcribed as five transcriptional units, that is, dnfIH, dnfR, dnfG, dnfABCDE and dnfF. DnfR activates the transcription of dnfIH, dnfG and dnfABCDE genes, and represses its own transcription. The intact 1506-bp dnfR gene was required for activation of Dirammox. Electrophoretic mobility shift assays and DNase I footprinting analyses showed that DnfR has one binding site in the dnfH-dnfR intergenic region and two binding sites in the dnfG-dnfA intergenic region. Three binding sites of DnfR shared a 6-bp repeated conserved sequence 5'-GGTCTG-N17 -GGTCTG-3' which was essential for the transcription of downstream target genes. Cysteine and glutamate act as possible effectors of DnfR to activate the transcription of transcriptional units of dnfG and dnfABCDE, respectively. This study provided new insights in the transcriptional regulation mechanism of Dirammox by DnfR in A. faecalis JQ135.


Asunto(s)
Alcaligenes faecalis , Alcaligenes faecalis/química , Alcaligenes faecalis/genética , Alcaligenes faecalis/metabolismo , Amoníaco/metabolismo , Sitios de Unión , Factores de Transcripción/genética , Transcripción Genética , Proteínas Bacterianas/metabolismo , Regulación Bacteriana de la Expresión Génica
6.
Stroke ; 53(5): 1682-1691, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-34847706

RESUMEN

BACKGROUND: Language dysfunction is rarely seen in patients with unruptured brain arteriovenous malformation (AVM) albeit the AVM nidus involving language areas, which provides a unique disease model to study language reorganization. The objective of this study was to investigate the impairment and reorganization patterns and characteristics of language-related white matter in AVMs located at different brain areas. METHODS: Thirty-three patients with AVMs involving language areas were prospectively enrolled. Patients were categorized into 3 groups according to the lesion locations: the frontal (14 patients), temporal (15 patients), and parietal groups (4 patients). Thirty age- and sex-matched healthy controls were enrolled as comparison. All participants underwent diffusion tensor imaging scans, and automated fiber quantification method was applied to quantitatively study the difference of segmented language-related white matter connectivity between 3 AVM groups and control group. RESULTS: Language functions were normal in all subjects according to Western Aphasia Battery test. In the frontal group, fractional anisotropy (FA) value decreased in the left arcuate fascicle and increased in left superior longitudinal fasciculus and uncinate fascicle; in the temporal group, FA values decreased in left inferior fronto-occipital fascicle and inferior longitudinal fascicle and increased in right anterior thalamic radiation and uncinate fascicle; in the parietal group, FA values decreased in left arcuate fascicle and inferior longitudinal fascicle and increased in bilateral anterior thalamic radiations and uncinate fascicles and right inferior fronto-occipital fascicle. In fascicles with decreased FA values, the increase of radial diffusivity was common, and fascicles with increased FA values usually presented along with increased axial diffusivity values. CONCLUSIONS: Remodeling of language-related white matter occurs when traditional language areas are involved by AVM nidus, and its reorganization patterns vary with locations of AVM nidus. Fascicle impairment is mainly caused by the myelin deficits, and its plasticity may be dominated by the axon remodeling procedure.


Asunto(s)
Malformaciones Arteriovenosas , Sustancia Blanca , Malformaciones Arteriovenosas/patología , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Imagen de Difusión Tensora/métodos , Humanos , Lenguaje , Sustancia Blanca/diagnóstico por imagen
7.
Appl Environ Microbiol ; 88(6): e0226121, 2022 03 22.
Artículo en Inglés | MEDLINE | ID: mdl-35108103

RESUMEN

Ammonia oxidation is an important process in both the natural nitrogen cycle and nitrogen removal from engineered ecosystems. Recently, a new ammonia oxidation pathway termed Dirammox (direct ammonia oxidation, NH3→NH2OH→N2) has been identified in Alcaligenes ammonioxydans. However, whether Dirammox is present in other microbes, as well as its genetic regulation, remains unknown. In this study, it was found that the metabolically versatile bacterium Alcaligenes faecalis strain JQ135 could efficiently convert ammonia into N2 via NH2OH under aerobic conditions. Genetic deletion and complementation results suggest that dnfABC is responsible for the ammonia oxidation to N2 in this strain. Strain JQ135 also employs aerobic denitrification, mainly producing N2O and trace amounts of N2, with nitrite as the sole nitrogen source. Deletion of the nirK and nosZ genes, which are essential for denitrification, did not impair the capability of JQ135 to oxidize ammonia to N2 (i.e., Dirammox is independent of denitrification). Furthermore, it was also demonstrated that pod (which encodes pyruvic oxime dioxygenase) was not involved in Dirammox and that AFA_16745 (which was previously annotated as ammonia monooxygenase and is widespread in heterotrophic bacteria) was not an ammonia monooxygenase. The MocR-family transcriptional regulator DnfR was characterized as an activator of the dnfABC operon with the binding motif 5'-TGGTCTGT-3' in the promoter region. A bioinformatic survey showed that homologs of dnf genes are widely distributed in heterotrophic bacteria. In conclusion, this work demonstrates that, besides A. ammonioxydans, Dirammox occurs in other bacteria and is regulated by the MocR-family transcriptional regulator DnfR. IMPORTANCE Microbial ammonia oxidation is a key and rate-limiting step of the nitrogen cycle. Three previously known ammonia oxidation pathways (i.e., nitrification, anaerobic ammonia oxidation [Anammox], and complete ammonia oxidation [Comammox]) are mediated by autotrophic microbes. However, the genetic foundations of ammonia oxidation by heterotrophic microorganisms have not been investigated in depth. Recently, a previously unknown pathway, termed direct ammonia oxidation to N2 (Dirammox), has been identified in the heterotrophic bacterium Alcaligenes ammonioxydans HO-1. This paper shows that, in the metabolically versatile bacterium Alcaligenes faecalis JQ135, the Dirammox pathway is mediated by dnf genes, which are independent of the denitrification pathway. A bioinformatic survey suggests that homologs of dnf genes are widely distributed in bacteria. These findings enhance the understanding of the molecular mechanisms of heterotrophic ammonia oxidation to N2.


Asunto(s)
Alcaligenes faecalis , Aerobiosis , Alcaligenes faecalis/genética , Alcaligenes faecalis/metabolismo , Amoníaco/metabolismo , Desnitrificación , Ecosistema , Nitrificación , Nitritos/metabolismo , Nitrógeno/metabolismo
8.
Environ Sci Technol ; 56(15): 10925-10934, 2022 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-35820052

RESUMEN

Conventional water disinfection methods such as chlorination typically involve the generation of harmful disinfection byproducts and intensive chemical consumption. Emerging electroporation disinfection techniques using nanowire-enhanced local electric fields inactivate microbes by damaging their outer structures without byproduct formation or chemical dosing. However, this physical-based method suffers from a limited inactivation efficiency under high water flux due to an insufficient contact time. Herein, we integrate electrochlorination with nanowire-enhanced electroporation to achieve a synergistic flow-through process for efficient water disinfection targeting bacteria and viruses. Electroporation at the cathode induces sub-lethal damages on the microbial outer structures. Subsequently, electrogenerated active chlorine at the anode aggravates these electroporation-induced injuries to the level of lethal damage. This sequential flow-through disinfection system achieves complete disinfection (>6.0-log) under a very high water flux of 2.4 × 104 L/(m2 h) with an applied voltage of 2.0 V. This disinfection efficiency is 8 times faster than that of electroporation alone. Further, the specific energy consumption for the disinfection by this novel process is extremely low (8 × 10-4 kW h/m3). Our results demonstrate a promising method for rapid and energy-efficient water disinfection by coupling electroporation with electrochlorination to meet vital needs for pathogen elimination.


Asunto(s)
Nanocables , Purificación del Agua , Cloro/química , Desinfección , Electroporación , Nanocables/química , Agua , Purificación del Agua/métodos
9.
Plant Dis ; 2022 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-36383992

RESUMEN

Sugarcane (Saccharum officinarum) is an economically important crop and is extensively planted across China. In August 2020, leaf midribs with red lesions were observed on cultivar 'Yunzhe 081609' in Kaiyuan (103.27°E, 23.71°N), Yunnan, Southwestern China. In July to August 2021, similar symptoms were observed on cultivar 'Liucheng 05-136' in Hechi (108.48°E, 24.47°N), Guangxi, and on cultivars 'Yingyu 91-59' and 'Yunzhe 081609' in Lingcang (99.45°E, 23.33°N), Yunnan. Initially symptoms appeared as red spots on the leaf midribs, which gradually expanded, forming elongated red lesions. At high severity, the leaves broke and hung down. Disease incidence of leaves was estimated at 30 to 50% across the locations. To identify the etiology of this disease, three symptomatic leaves were collected from cultivars 'Liucheng 05-136', 'Yingyu 91-59', and 'Yunzhe 081609', respectively. Symptomatic leaf midribs were cut to small fragments (3 × 5 mm), surface sterilized with 70% ethanol for 30 s followed by 1% NaClO for 1 min, rinsed with sterilized distilled water three times, air dried on sterile filter paper, plated on potato dextrose agar (PDA), and incubated at 28°C in the dark. Ten isolates with similar morphological characteristics were obtained. Colonies on PDA were white to grayish-white with aerial mycelium growing initially upward and then forming clusters. After 10 days, mycelia turned to grayish black. Immature conidia were initially hyaline, aseptate, and ellipsoid. Mature conidia became dark brown, septate, longitudinal striate, and measured 21.2 to 25.8 × 11.4 to 16.4 µm (n = 30). Morphologically, the isolates were identified as Lasiodiplodia theobromae (Alves et al. 2008). For molecular identification, genomic DNA of four representative isolates (LTGX1, LTGX2, LTYN1 and LTYN2) was extracted using the Ezup Column Fungi Genomic DNA Purification kit. The internal transcribed spacer (ITS) region of rDNA, translation elongation factor 1-alpha (TEF-1α) gene, and ß-tubulin (TUB) gene were amplified with primer pairs ITS1/ITS4 for ITS, EF1-728F/EF1-986R for TEF-1α, and Bt2a/Bt2b for TUB, respectively (Glass and Donaldson 1995; Carbone and Kohn 1999; White et al. 1990), and then sequenced. The ITS (ON533336-ON533339), TEF-1α (ON939550-ON939553) and TUB (OP747306-OP747309) sequences were deposited in GenBank. BLAST searches showed >99% nucleotide identity to the sequences of ex-type isolate CBS 164.96 of L. theobromae (ITS, 99.8% to AY640255; TEF-1α, 99.9% to AY640258; TBU, 100% to EU673110). Phylogenetic analysis using maximum likelihood based on the combined ITS, TEF-1α, and TUB sequences of the isolates and reference sequences of Lasiodiplodia spp. downloaded from the GenBank indicated the isolates obtained in this study formed a clade strongly supported based on bootstrap values (100%) to the ex-type isolate CBS 164.96 sequences of L. theobromae. For pathogenicity tests, three healthy 6-month-old potted sugarcane leaf midribs of cultivar 'Yunzhe 081609' were wounded with a sterile needle, then inoculated using 8-mm mycelial agar plugs from a 10-day-old culture of strain LTYN1, and covered with wet cotton to maintain high relative humidity. Sterile PDA plugs were used as controls. Plants were placed in a greenhouse at 28 to 32°C. The test was conducted twice. Five days after inoculation, red lesions appeared on the inoculated leaf midribs. These symptoms were similar to those observed in the field. The leaves used for negative controls remained symptomless. The same fungus (L. theobromae) was re-isolated from all inoculated-symptomatic tissues; and isolates had the same morphological traits mentioned above. The DNA sequence data of these isolates was also similar than the original isolates. The association of L. theobromae with S. officinarum was recorded earlier in Cuba (Urtiaga, 1986), Myanmar (Thaung, 2008) and the Philippines (Reinking, 1919). Leaf midribs with red lesions caused by Colletotrichum falcatum has already been described around the world (Costa et al. 2021; Hossain et al. 2021; Xie et al. 2019). All together, this information indicates that L. theobromae is one of the causal agent of the red lesions symptoms on the sugarcane leaf midribs. To our knowledge, this is the first report of L. theobromae causing red lesions on leaf midribs of sugarcane in China. Further research will focus on developing management strategies to control this disease effectively.

10.
Foot Ankle Surg ; 28(7): 1002-1007, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35177328

RESUMEN

PURPOSE: This study aimed to address the relationship between surgeon volume and the risk of complications following surgeries of displaced intra-articular calcaneal fractures (DIACFs). METHODS: We retrospectively reviewed the medical records and the follow-up registers for patients who underwent open reduction and internal fixation with plate/screws in our center between January 2015 and June 2020. Surgeon volume was defined as the number of surgically treated calcaneal fractures within the past 12 months, and was dichotomized on basis of the optimal cut-off value. The outcome measure was the documented overall complications within 1 year after surgery. Four logistics regression models were constructed to examine the potential relationship between surgeon volume and complications. RESULTS: Among 585 patients, 49 had documented complications, representing an overall rate of 8.4%. The overall complication rate was 20.0% (22/111) in patients operated on by the low-volume surgeons and 5.7% (27/474) by the high-volume surgeons, with a significant difference (p < 0.001). The 4 multivariate analyses showed steady and robust inverse volume-complication relationship, with OR ranging from 3.8 to 4.4. The restricted cubic splines adjusted for total covariates showed the non-linear fitting "L-shape" or "reverse J-shape" curve (p = 0.041), and the OR was reduced until 10 cases, beyond which the curve leveled. CONCLUSIONS: Our findings reflected the important role of maintaining necessary operative cases, potentially informing optimized surgical care management.


Asunto(s)
Traumatismos del Tobillo , Calcáneo , Traumatismos de los Pies , Fracturas Óseas , Fracturas Intraarticulares , Cirujanos , Traumatismos del Tobillo/etiología , Calcáneo/cirugía , Traumatismos de los Pies/etiología , Fijación Interna de Fracturas/efectos adversos , Fracturas Óseas/cirugía , Humanos , Fracturas Intraarticulares/etiología , Fracturas Intraarticulares/cirugía , Estudios Retrospectivos , Resultado del Tratamiento
11.
Hum Brain Mapp ; 42(18): 6014-6027, 2021 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-34582074

RESUMEN

Brain arteriovenous malformation (AVM), a presumed congenital lesion, may involve traditional language areas but usually does not lead to language dysfunction unless it ruptures. The objective of this research was to study right-hemispheric language reorganization patterns in patients with brain AVMs using functional magnetic resonance imaging (fMRI). We prospectively enrolled 30 AVM patients with lesions involving language areas and 32 age- and sex-matched healthy controls. Each subject underwent fMRI during three language tasks: visual synonym judgment, oral word reading, and auditory sentence comprehension. The activation differences between the AVM and control groups were investigated by voxelwise analysis. Lateralization indices (LIs) for the frontal lobe, temporal lobe, and cerebellum were compared between the two groups, respectively. Results suggested that the language functions of AVM patients and controls were all normal. Voxelwise analysis showed no significantly different activations between the two groups in visual synonym judgment and oral word reading tasks. In auditory sentence comprehension task, AVM patients had significantly more activations in the right precentral gyrus (BA 6) and right cerebellar lobule VI (AAL 9042). According to the LI results, the frontal lobe in oral word reading task and the temporal lobe in auditory sentence comprehension task were significantly more right-lateralized in the AVM group. These findings suggest that for patients with AVMs involving language cortex, different language reorganization patterns may develop for different language functions. The recruitment of brain areas in the right cerebral and cerebellar hemispheres may play a compensatory role in the reorganized language network of AVM patients.


Asunto(s)
Mapeo Encefálico , Cerebelo/fisiopatología , Corteza Cerebral/fisiopatología , Lateralidad Funcional/fisiología , Malformaciones Arteriovenosas Intracraneales/patología , Psicolingüística , Lectura , Percepción del Habla/fisiología , Adolescente , Adulto , Cerebelo/diagnóstico por imagen , Corteza Cerebral/diagnóstico por imagen , Comprensión/fisiología , Femenino , Humanos , Malformaciones Arteriovenosas Intracraneales/diagnóstico por imagen , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Adulto Joven
12.
J Immunol ; 202(10): 2991-2998, 2019 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-30971440

RESUMEN

T follicular helper (Tfh) cells are essential for germinal center B cell responses. The molecular mechanism underlying the initial Tfh cell differentiation, however, is still incompletely understood. In this study, we show that in vivo, despite enhanced non-Tfh cell effector functions, the deletion of transcription factor Bach2 results in preferential Tfh cell differentiation. Mechanistically, the deletion of Bach2 leads to the induction of CXCR5 expression even before the upregulation of Ascl2. Subsequently, we have identified a novel regulatory element in the murine CXCR5 locus that negatively regulates CXCR5 promoter activities in a Bach2-dependent manner. Bach2 deficiency eventually results in a collapsed CD4+ T cell response with severely impaired CD4+ T cell memory, including Tfh cell memory. Our results demonstrate that Bach2 critically regulates Tfh cell differentiation and CD4+ T cell memory.


Asunto(s)
Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/inmunología , Diferenciación Celular/inmunología , Memoria Inmunológica , Linfocitos T Colaboradores-Inductores/inmunología , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/inmunología , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Diferenciación Celular/genética , Regulación de la Expresión Génica/inmunología , Ratones , Ratones Transgénicos , Receptores CXCR5/genética , Receptores CXCR5/inmunología , Linfocitos T Colaboradores-Inductores/citología
13.
J Immunol ; 200(2): 586-594, 2018 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-29212910

RESUMEN

T follicular helper (Tfh) cells play an essential role in the formation of germinal centers (GC) and generation of high-affinity Abs. The homing of activated CD4+ T cells into B cell follicles and the involvement of key costimulatory and coinhibitory molecules are critical in controlling both the initiation and the magnitude of GC responses. Meanwhile, studies have shown that a high number of single clone B cells leads to intraclonal competition, which inhibits the generation of high-affinity Abs. Our previous work has shown that transcription factor Foxp1 is a critical negative regulator of Tfh cell differentiation. In this study, we report that the deletion of Foxp1 leads to a high proportion of activated CD4+ T cells homing into B cell follicles with faster kinetics, resulting in earlier GC formation. In addition, we show that Foxp1-deficient Tfh cells restore the generation of high-affinity Abs when cotransferred with high numbers of single clone B cells. We find that Foxp1 regulates the expression levels of cytotoxic T lymphocyte-associated Ag-4 (CTLA-4) in activated CD4+ T cells and that Ctla4 is a direct Foxp1 target. Finally, we demonstrate that CTLA-4 expression on conventional CD4+ T cells plays a cell-intrinsic role in Tfh cell differentiation in vivo, and CTLA-4 blockade helps abolish the intraclonal competition of B cells in generating high-affinity Abs.


Asunto(s)
Antígeno CTLA-4/metabolismo , Diferenciación Celular/inmunología , Movimiento Celular/inmunología , Factores de Transcripción Forkhead/metabolismo , Centro Germinal/inmunología , Proteínas Represoras/metabolismo , Linfocitos T Colaboradores-Inductores/inmunología , Linfocitos T Colaboradores-Inductores/metabolismo , Animales , Linfocitos B/inmunología , Linfocitos B/metabolismo , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Antígeno CTLA-4/genética , Inmunomodulación , Activación de Linfocitos/genética , Activación de Linfocitos/inmunología , Ratones , Ratones Transgénicos , Linfocitos T Colaboradores-Inductores/citología
14.
Appl Environ Microbiol ; 85(6)2019 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-30658983

RESUMEN

A simple aspirin-inducible system has been developed and characterized in Escherichia coli by employing the Psal promoter and SalR regulation system originally from Acinetobacter baylyi ADP1. Mutagenesis at the DNA binding domain (DBD) and chemical recognition domain (CRD) of the SalR protein in A. baylyi ADP1 suggests that the effector-free form, SalRr, can compete with the effector-bound form, SalRa, binding the Psal promoter and repressing gene transcription. The induction of the Psal promoter was compared in two different gene circuit designs: a simple regulation system (SRS) and positive autoregulation (PAR). Both regulatory circuits were induced in a dose-dependent manner in the presence of 0.05 to 10 µM aspirin. Overexpression of SalR in the SRS circuit reduced both baseline leakiness and the strength of the Psal promoter. The PAR circuit forms a positive feedback loop that fine-tunes the level of SalR. A mathematical simulation based on the SalRr/SalRa competitive binding model not only fit the observed experimental results in SRS and PAR circuits but also predicted the performance of a new gene circuit design for which weak expression of SalR in the SRS circuit should significantly improve induction strength. The experimental result is in good agreement with this prediction, validating the SalRr/SalRa competitive binding model. The aspirin-inducible systems were also functional in probiotic strain E. coli Nissle 1917 and SimCells produced from E. coli MC1000 ΔminD These well-characterized and modularized aspirin-inducible gene circuits would be useful biobricks for synthetic biology.IMPORTANCE An aspirin-inducible SalR/Psal regulation system, originally from Acinetobacter baylyi ADP1, has been designed for E. coli strains. SalR is a typical LysR-type transcriptional regulator (LTTR) family protein and activates the Psal promoter in the presence of aspirin or salicylate in the range of 0.05 to 10 µM. The experimental results and mathematical simulations support the competitive binding model of the SalR/Psal regulation system in which SalRr competes with SalRa to bind the Psal promoter and affect gene transcription. The competitive binding model successfully predicted that weak SalR expression would significantly improve the inducible strength of the SalR/Psal regulation system, which is confirmed by the experimental results. This provides an important mechanism model to fine-tune transcriptional regulation of the LTTR family, which is the largest family of transcriptional regulators in the prokaryotic kingdom. In addition, the SalR/Psal regulation system was also functional in probiotic strain E. coli Nissle 1917 and minicell-derived SimCells, which would be a useful biobrick for environmental and medical applications.


Asunto(s)
Aspirina/metabolismo , Técnicas Biosensibles/métodos , Escherichia coli/metabolismo , Acinetobacter/genética , Acinetobacter/metabolismo , Técnicas Biosensibles/instrumentación , Escherichia coli/genética , Regulación Bacteriana de la Expresión Génica , Redes Reguladoras de Genes , Regiones Promotoras Genéticas , Salicilatos/metabolismo
15.
Environ Sci Technol ; 53(6): 3238-3249, 2019 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-30768244

RESUMEN

Flow-through configuration for electrochemical disinfection is considered as a promising approach to minimize the formation of toxic byproducts and energy consumption via the enhanced convective mass transport as compared with conventional flow-by one. Under this hydrodynamic condition, it is essential to ascertain the effect of sequential electro-redox processes with the cathode/anode then anode/cathode arrangements on disinfection performance. Here, carbon fiber felt (CFF) was utilized to construct two flow-through electrode systems (FESs) with sequential reduction-oxidation (cathode-anode) or oxidation-reduction (anode-cathode) processes to systematically compare their disinfection performance toward a model Escherichia coli ( E. coli) pathogen. In-situ sampling and live/dead backlight staining experiments revealed that E. coli inactivation mainly occurred on anode via an adsorption-inactivation-desorption process. In reduction-oxidation system, after the cathode-pretreatment, bulk solution pH increased significantly, leading to the negative charge of E. coli cells. Hence, E. coli cells were adsorbed and inactivated easily on the subsequent anode, finally resulting in its much better disinfection performance and energy efficiency than the oxidation-reduction system. Application of 3.0 V resulted in ∼6.5 log E. coli removal at 1500 L m-2 h-1 (50 mL min-1), suggesting that portable devices can be designed from CFF-based FES with potential application for point-of-use water disinfection.


Asunto(s)
Desinfección , Agua , Fibra de Carbono , Técnicas Electroquímicas , Electrodos , Escherichia coli , Oxidación-Reducción
16.
Stroke ; 49(12): 2837-2843, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30571396

RESUMEN

Background and Purpose- The study goal was to evaluate cerebral perfusion in moyamoya patients with a novel staging system and investigate the association between differences of perfusion status and clinical outcomes in patients treated with revascularization. Methods- About 506 consecutive patients from 2009 to 2015 were enrolled. The perfusion status was evaluated by a staging system-the stage of preinfarction period based on the result of computed tomography perfusion. Hemisphere in different perfusion stage was compared between hemorrhagic patients (n=155) and ischemic patients (n=351). The modified Rankin Scale was applied to evaluate the prognosis of patients. Results- In the enrolled 506 patients: 229 hemispheres (22.6%) with normal perfusion, 72 hemispheres (7.1%) in stage I, 205 hemispheres (20.3%) in stage II, 308 hemispheres (30.4%) in stage III, and 198 hemispheres (19.6%) in stage IV. Significant difference was observed in stage distribution between hemorrhagic patients and ischemic patients ( P<0.01). The ratio of hemispheres with normal perfusion in hemorrhagic group is more than the ischemic group ( P<0.05; odds ratio, 1.440; 95% CI, 1.144-1.811). The ratio of hemispheres in stage III in ischemic group is more than the hemorrhagic group ( P<0.01; odds ratio, 0.618, 95% CI, 0.487-0.783). In the prognosis-related analysis, the stage I group has the highest improved ratio (73.9%) and the normal perfusion group has the lowest improved ratio (33.3%). The improved ratio has a decreasing tendency from stage I to stage IV. Conclusions- The novel preinfarction staging system is a valuable assessment tool to evaluate cerebral perfusion status in moyamoya patients and predict the efficacy of revascularization. Ischemic patients suffer more from hypoperfusion. Patients in stage I and stage II are more likely to obtain improvement after revascularization. This is a retrospective study.


Asunto(s)
Isquemia Encefálica/diagnóstico por imagen , Circulación Cerebrovascular , Hemorragias Intracraneales/diagnóstico por imagen , Enfermedad de Moyamoya/diagnóstico por imagen , Adolescente , Adulto , Angiografía de Substracción Digital , Isquemia Encefálica/fisiopatología , Angiografía Cerebral , Revascularización Cerebral/métodos , Niño , Preescolar , Femenino , Humanos , Hemorragias Intracraneales/fisiopatología , Angiografía por Resonancia Magnética , Masculino , Persona de Mediana Edad , Enfermedad de Moyamoya/fisiopatología , Enfermedad de Moyamoya/cirugía , Selección de Paciente , Imagen de Perfusión , Pronóstico , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Tomografía Computarizada por Rayos X , Adulto Joven
17.
J Transl Med ; 16(1): 274, 2018 10 04.
Artículo en Inglés | MEDLINE | ID: mdl-30286759

RESUMEN

BACKGROUND: The aim of the study is described the regulatory mechanisms and prognostic values of differentially expressed RNAs in prostate cancer and construct an mRNA signature that predicts survival. METHODS: The RNA profiles of 499 prostate cancer tissues and 52 non-prostate cancer tissues from TCGA were analyzed. The differential expression of RNAs was examined using the edgeR package. Survival was analyzed by Kaplan-Meier method. microRNA (miRNA), messenger RNA (mRNA), and long non-coding RNA (lncRNA) networks from the miRcode database were constructed, based on the differentially expressed RNAs between non-prostate and prostate cancer tissues. RESULTS: A total of 773 lncRNAs, 1417 mRNAs, and 58 miRNAs were differentially expressed between non-prostate and prostate cancer samples. The newly constructed ceRNA network comprised 63 prostate cancer-specific lncRNAs, 13 miRNAs, and 18 mRNAs. Three of 63 differentially expressed lncRNAs and 1 of 18 differentially expressed mRNAs were significantly associated with overall survival in prostate cancer (P value < 0.05). After the univariate and multivariate Cox regression analyses, 4 mRNAs (HOXB5, GPC2, PGA5, and AMBN) were screened and used to establish a predictive model for the overall survival of patients. Our ROC curve analysis revealed that the 4-mRNA signature performed well. CONCLUSION: These ceRNAs may play a critical role in the progression and metastasis of prostate cancer and are thus candidate therapeutic targets and potential prognostic biomarkers. A novel model that incorporated these candidates was established and might provide more powerful prognostic information in predicting survival in prostate cancer.


Asunto(s)
Redes Reguladoras de Genes , Neoplasias de la Próstata/genética , ARN Mensajero/genética , ARN Neoplásico/genética , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Ontología de Genes , Humanos , Masculino , Análisis Multivariante , Pronóstico , Modelos de Riesgos Proporcionales , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , ARN Mensajero/metabolismo , ARN Neoplásico/metabolismo , Análisis de Supervivencia
18.
J Immunol ; 196(9): 3537-41, 2016 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-27001958

RESUMEN

Previously we have shown that transcription factor Foxp1 plays an essential role in maintaining naive T cell quiescence; in the absence of Foxp1, mature naive CD8(+) T cells proliferate in direct response to homeostatic cytokine IL-7. In this study, we report that the deletion of Foxp1 in naive CD8(+) T cells leads to enhanced activation of the PI3K/Akt/mammalian target of rapamycin signaling pathway and its downstream cell growth and metabolism targets in response to IL-7. We found that Foxp1 directly regulates PI3K interacting protein 1, a negative regulator of PI3K. Additionally, we found that deletion of Foxp1 in naive CD8(+) T cells results in increased expression levels of E2fs, the critical components for cell cycle progression and proliferation, in a manner that is not associated with increased phosphorylation of retinoblastoma protein. Taken together, our studies suggest that Foxp1 enforces naive CD8(+) T cell quiescence by simultaneously repressing key pathways in both cellular metabolism and cell cycle progression.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Ciclo Celular , Factores de Transcripción Forkhead/metabolismo , Regulación de la Expresión Génica , Interleucina-7/metabolismo , Proteínas Represoras/metabolismo , Animales , Linfocitos T CD8-positivos/citología , Linfocitos T CD8-positivos/efectos de los fármacos , Linfocitos T CD8-positivos/metabolismo , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Ciclo Celular/fisiología , Proliferación Celular , Factores de Transcripción Forkhead/deficiencia , Factores de Transcripción Forkhead/genética , Homeostasis , Interleucina-7/inmunología , Interleucina-7/farmacología , Péptidos y Proteínas de Señalización Intracelular , Proteínas de la Membrana , Fosfatidilinositol 3-Quinasas/genética , Fosfatidilinositol 3-Quinasas/metabolismo , Fosforilación , Proteínas Represoras/deficiencia , Proteínas Represoras/genética , Proteína de Retinoblastoma/inmunología , Proteína de Retinoblastoma/metabolismo , Transducción de Señal , Serina-Treonina Quinasas TOR/metabolismo
19.
Anticancer Drugs ; 28(6): 596-602, 2017 07.
Artículo en Inglés | MEDLINE | ID: mdl-28430744

RESUMEN

The role of autophagy in the anticancer activity of gemcitabine (GEM) in bladder cancer is unclear. The aim of this study is to determine whether GEM activates autophagy, the role of autophagy in the anticancer activity of GEM, and the underlying mechanism by which GEM induces autophagy. Human bladder cancer cell lines T24 and BIU87 were treated with GEM in vitro. Cell viability was measured using the Cell Counting Kit-8 assay. Apoptosis was detected by annexin V assay and western blot. Autophagy was measured by western blot and transmission electron microscopy. c-Jun N-terminal kinase (JNK) activation was detected by western blot. Chemical inhibitors were used for intervention of JNK and autophagy. GEM killed bladder cancer cells, which was associated with apoptosis induction. Autophagy was effectively activated by GEM. Suppressing autophagy in GEM-treated cells significantly decreased cell viability, which was associated with increased apoptosis. GEM-induced JNK activation and suppressed B-cell lymphoma 2 expression. The JNK inhibitor SP600125 inhibited GEM-induced autophagy activation and increased GEM's cytotoxicity. GEM kills bladder cancer cells through apoptosis. Meanwhile, JNK-mediated autophagy was activated, which protects the cells against apoptosis. Therefore, inhibition of autophagy could be exploited to enhance the anticancer efficacy of GEM for treating bladder cancer.


Asunto(s)
Antimetabolitos Antineoplásicos/farmacología , Desoxicitidina/análogos & derivados , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Neoplasias de la Vejiga Urinaria/enzimología , Antracenos/farmacología , Apoptosis/efectos de los fármacos , Apoptosis/fisiología , Autofagia/efectos de los fármacos , Autofagia/fisiología , Línea Celular Tumoral , Desoxicitidina/farmacología , Activación Enzimática/efectos de los fármacos , Humanos , Proteínas Quinasas JNK Activadas por Mitógenos/antagonistas & inhibidores , Neoplasias de la Vejiga Urinaria/patología , Gemcitabina
20.
J Autoimmun ; 66: 108-17, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26432598

RESUMEN

There is a significant unmet need in the treatment of primary biliary cirrhosis (PBC) despite significant data on the effector pathways that lead to biliary duct damage. We focused attention on a murine model of PBC, the dominant negative transforming growth factor ß receptor II (Tg) mice. To further define the pathways that lead to biliary pathology in these mice, we developed Tg mice deleted of CD4 cells (CD4(-/-)Tg). Interestingly, these mice developed more severe cholangitis than control Tg mice. These mice, which lack CD4 cells, manifested increased levels of IFN-γ produced by effector CD8 cells. It appears that increased cholangitis is due to the absence of CD4 Treg cells. Based on these data, we parabiosed CD4(-/-)Tg mice with established disease at 8-9 weeks of age with C57BL/6 control mice. Such parabiotic "twins" had a significant reduction in autoimmune cholangitis, even though they had established pathology at the time of surgery. We prepared mixed bone marrow chimera mice constructed from CD4(-/-)Tg and CD8(-/-) mice and not only was cholangitis improved, but a decrease in terminally differentiated CD8(+) T effector cells in the presence of wild type CD4 cells was noted. In conclusion, "correcting" the CD4 T cell subset, even in the presence of pathogenic CD8 T cells, is effective in treating autoimmune cholangitis.


Asunto(s)
Enfermedades Autoinmunes/cirugía , Colangitis/cirugía , Cirrosis Hepática Biliar/cirugía , Parabiosis/métodos , Animales , Enfermedades Autoinmunes/inmunología , Conductos Biliares/inmunología , Conductos Biliares/patología , Antígenos CD4/genética , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Colangitis/inmunología , Modelos Animales de Enfermedad , Femenino , Trasplante de Células Madre Hematopoyéticas/métodos , Humanos , Hígado/inmunología , Hígado/patología , Cirrosis Hepática Biliar/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Mutación , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/inmunología , Receptor Tipo II de Factor de Crecimiento Transformador beta , Receptores de Factores de Crecimiento Transformadores beta/genética , Receptores de Factores de Crecimiento Transformadores beta/inmunología
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