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1.
Phys Chem Chem Phys ; 26(3): 2387-2394, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38168687

RESUMO

Prussian blue framework materials are expected to be the next generation of electrode materials for commercial batteries because their three-dimensional framework structures facilitate the rapid transport and storage of ions and a variety of redox processes. This work compared the calculations of the model before and after the dispersion correction, and the model considering the effect of van der Waals force was more stable. In addition, the distances between H, C and N atoms were within the range of van der Waals force. Thus it was confirmed that NH4+ was adsorbed on the Ax site in the Prussian blue framework material (AxMa[Mb(CN)6]) by van der Waals interaction, and the charge transfer was mainly achieved by the interaction between the H atom in NH4+ and the N atom in the Prussian blue framework. On this basis, the properties of NH4+ batteries were theoretically screened for the Fe-based Prussian blue analogues (PBAs) with different Ma elements (Ma = Co, Cu, Fe, Mg, Mn, Ni, V or Zn). Considering the regulating effect of different metal elements on the electronic structures of PBAs, MgFe and ZnFe PBAs as the electrode materials of NH4+ batteries are expected to show excellent electrochemical energy storage performance in organic electrolytes.

2.
Phys Chem Chem Phys ; 25(6): 4724-4731, 2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36661895

RESUMO

In the present work, we evaluated the hydrogen evolution reaction (HER) performance of transition metal (Co, Fe, Ni, Mn, and Mo) doped vanadium carbides (VC). In addition, the doping atoms were screened separately on the (100), (110) and (111) crystal planes to analyze the differences in HER activities. Among all the calculated models, Mn-VC(100) exhibited the best catalytic hydrogen evolution performance with a Gibbs free energy for hydrogen adsorption (ΔGH*) of 0.0012 eV. Doping Mn greatly improved the HER performance of VC(100) by enhancing the adsorption of hydrogen on the catalyst surface. The analysis of the electronic density of states and charge transfer confirmed that doping transition metal atoms into the surfaces of the VC model successfully optimized the electronic structure and promoted catalytic reaction kinetics. Besides, the relationship between the catalytic activity and pH value of different models was considered, and doping Co atoms on the (100) crystal plane could effectively modify the pH value range applicable for the efficient HER. Interestingly, even if the same metal atoms were doped, various active sites of VC models exhibited different catalytic performances due to disparate exposed crystal planes and pH values. This indicates that the main exposed crystal surfaces and the pH range of application need to be considered when selecting the appropriate doping element for the catalyst.

3.
New Phytol ; 235(1): 247-262, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35338654

RESUMO

In eukaryotes, N6 -methyladenosine (m6 A) is abundant on mRNA, and plays key roles in the regulation of RNA function. However, the roles and regulatory mechanisms of m6 A in phytopathogenic fungi are still largely unknown. Combined with biochemical analysis, MeRIP-seq and RNA-seq methods, as well as biological analysis, we showed that Magnaporthe oryzae MTA1 gene is an orthologue of human METTL4, which is involved in m6 A modification and plays a critical role in autophagy for fungal infection. The Δmta1 mutant showed reduced virulence due to blockage of appressorial penetration and invasive growth. Moreover, the autophagy process was severely disordered in the mutant. MeRIP-seq identified 659 hypomethylated m6 A peaks covering 595 mRNAs in Δmta1 appressoria, 114 m6 A peaks was negatively related to mRNA abundance, including several ATG gene transcripts. Typically, the mRNA abundance of MoATG8 was also increased in the single m6 A site mutant ∆atg8/MoATG8A982C , leading to an autophagy disorder. Our findings reveal the functional importance of the m6 A methylation in infection of M. oryzae and provide novel insight into the regulatory mechanisms of plant pathogenic fungi.


Assuntos
Magnaporthe , Oryza , Ascomicetos , Autofagia/genética , Proteínas Fúngicas/genética , Oryza/genética , Oryza/microbiologia , Doenças das Plantas/microbiologia , RNA , RNA Mensageiro/genética
4.
J Exp Bot ; 73(11): 3417-3430, 2022 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-35182423

RESUMO

Starch biosynthesis during rice endosperm development is important for grain quality, as it influences grain size and physico-chemical properties, which together determine rice eating quality. Cereal starch biosynthetic pathways have been comprehensively investigated; however, their regulation, especially by transcriptional repressors remains largely unknown. Here, we identified a DUF1645 domain-containing protein, STRESS_tolerance and GRAIN_LENGTH (OsSGL), that participates in regulating rice starch biosynthesis. Overexpression of OsSGL reduced total starch and amylose content in the endosperm compared with the wild type. Chromatin immunoprecipitation sequencing and RNA-seq analyses indicated that OsSGL targets the transcriptional activity of several starch and sucrose metabolism genes. In addition, ChIP-qPCR, yeast one-hybrid, EMSA and dual-luciferase assays demonstrated that OsSGL directly inhibits the expression of SUCROSE SYNTHASE 1 (OsSUS1) in the endosperm. Furthermore, OsSUS1 interacts with OsSGL to release its transcriptional repression ability. Unexpectedly, our results also show that knock down and mutation of OsSGL disrupts the starch biosynthetic pathway, causing lower starch and amylose content. Therefore, our findings demonstrate that accurate control of OsSGL homeostasis is essential for starch synthesis and grain quality. In addition, we revealed the molecular mechanism of OsSGL in regulating starch biosynthesis-related genes, which are required for grain quality.


Assuntos
Oryza , Amilose/metabolismo , Grão Comestível , Endosperma/genética , Endosperma/metabolismo , Regulação da Expressão Gênica de Plantas , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Amido/metabolismo , Fatores de Transcrição/metabolismo
5.
Plant Dis ; 2022 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-35815958

RESUMO

Palm grass (Setaria palmifolia) has been used as an ornamental plant and vegetable crop (Wu, 2009; Plarre, 1995). In June 2019, 2-10 mm severe leaf lesions with gray centers and brown-yellow edges were observed on the leaves of palm grass in Liuyang city (28°43'N, 114°12'E), Hunan province, China (Fig. 1A). Disease incidence on leaves was 20 - 40%. The infected leaves were collected and disinfected with 75% alcohol for 30 sec and 1% sodium hypochlorite for 1 min, followed by three rinses in sterilized ddH2O, dried on sterilized filter paper, and incubated on water agar for 48 h under continuous fluorescent light at 26℃. Then, typical pyriform and 2-septate conidia (23.97 - 30.37 × 7.42 - 9.98 µm, N = 30) appeared at the lesions (Fig. 1B). Four single-spore were captured, and then grew on oatmeal tomato agar for seven days under continuous fluorescent light at 26℃ to obtain four isolates (LY-ZY-7a, -7b, -9b and -9c) and produce conidia for inoculation tests. The colony morphology of LY-ZY-7b on OTA was gray and floccose, and the growth rate was 6.15 - 6.31 mm/d at 26 °C (Fig. 1C). Spores of LY-ZY-7b were washed off with sterilized ddH2O plus 0.025% Tween-20 to make spore suspensions. For scratch inoculation, 10 µL spore suspension (1 × 105 spores/mL) was inoculated on the wound scratched with a sterilized pin along the vein (3 mm × 3 mm) on palm grass middle leaf of 4-week-old seedlings. The inoculated leaves were sealed in a 15-cm Petri dish. For spray inoculation, 20 mL spore suspension (5 × 104 spores/mL) was made and sprayed on ten healthy palm grasses of 4-week-old seedlings. Plants used as negative controls were sprayed with sterilized ddH2O plus 0.025% Tween-20 (Liu et al. 2022; Zhang et al. 2014). After inoculation, all plants were put into transparent boxes to maintain > 95% humidity and covered with black plastic bags for one day. Then, the boxes containing the plants were placed in a growth chamber at 26°C (12 h light / 12 h darkness photoperiod). After six days, typical blast-type lesions with brown-yellow edges were visible on the leaves. Control plants did not show symptoms (Fig. 1D, 1E). Microscopical examination showed that the conidia and conidiophore recovered from the lesion of the inoculated plants have the same morphology as those recovered from natural infected tissues (Fig. 1F, 1G). The colony morphology of the pathogen isolated from the artificially inoculated tissue was consistent with that of isolate LY-ZY-7b (Fig. 1C). The spore suspension (5 × 104 spores/mL) of isolate LY-ZY-7b and one rice-infecting strain P131 (Yang et al., 2010) was made and sprayed onto 4-week-old seedlings of three rice cultivars. But unfortunately, isolate LY-ZY-7b could not cause any disease lesions on the tested rice cultivars, whereas strain P131 produced many typical blast lesions on rice leaves (Fig. 1H). Then, the fungal genetic identity of four isolates (LY-ZY-7a, -7b, -9b, and -9c) was confirmed by comparison of the sequence obtained from partial DNA of Actin (ACT), ITS, and RPB1 loci from our isolates and those previously published by Klaubauf et al. 2014. The nucleotide sequences of ACT, ITS, and RPB1 were submitted to GenBank ON228695-ON228697 (ACT), ON210978-ON210980 (ITS), ON228698-ON228701 (RPB1). A phylogenetic tree deduced from a maximum likelihood analysis based on combined ACT-ITS-RPB1 sequence data of Pyricularia showed that these four isolates (LY-ZY-7a, -7b, -9b, and -9c) clustered together on Pyricularia oryzae, with a high bootstrap support value (Fig. 2). Based on morphological characteristics and molecular phylogeny, these four isolates were identified as P. oryzae (Klaubauf et al. 2014; Qi et al. 2019). To our knowledge, this is the first report of blast disease on palm grass caused by P. oryzae in China, which will help develop disease management strategies against palm grass blast. Moreover, as a host of P. oryzae, palm grass might contribute as an inoculum source for blast diseases on cereal crops (such as rice, wheat, and barley) caused by P. oryzae in the field.

6.
J Integr Plant Biol ; 64(5): 1044-1058, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35297190

RESUMO

Extremely high or low autophagy levels disrupt plant survival under nutrient starvation. Recently, autophagy has been reported to display rhythms in animals. However, the mechanism of circadian regulation of autophagy is still unclear. Here, we observed that autophagy has a robust rhythm and that various autophagy-related genes (ATGs) are rhythmically expressed in Arabidopsis. Chromatin immunoprecipitation (ChIP) and dual-luciferase (LUC) analyses showed that the core oscillator gene TIMING OF CAB EXPRESSION 1 (TOC1) directly binds to the promoters of ATG (ATG1a, ATG2, and ATG8d) and negatively regulates autophagy activities under nutritional stress. Furthermore, autophagy defects might affect endogenous rhythms by reducing the rhythm amplitude of TOC1 and shortening the rhythm period of CIRCADIAN CLOCK-ASSOCIATED 1 (CCA1). Autophagy is essential for the circadian clock pattern in seedling development and plant sensitivity to nutritional deficiencies. Taken together, our studies reveal a plant strategy in which the TOC1-ATG axis involved in autophagy-rhythm crosstalk to fine-tune the intensity of autophagy.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Relógios Circadianos , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Autofagia/genética , Relógios Circadianos/genética , Ritmo Circadiano/genética , Regulação da Expressão Gênica de Plantas , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
7.
Exp Cell Res ; 389(1): 111892, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32035135

RESUMO

CXCR5+ CD8 T cells, sometimes termed T follicular cytotoxic (Tfc) cells, are characterized by high proinflammatory cytokine and cytolytic molecule expression and low exhaustion and checkpoint molecule expression. Additionally, Tfc cells could promote B cell responses and support Ig release. It is yet unclear how Tfc cells could help B cells when they have the potential to mediate cytotoxicity at the same time. In this study, we found that Tfc cells expressed significantly higher levels of CD40L than non-Tfc CD8 T cells. Interestingly, Tfc cells from colorectal cancer (CRC) patients presented significantly higher CD40L than Tfc cells from healthy controls in a manner that was associated with CRC stage. Coincubation of Tfc cells and autologous B cells resulted in higher CD40L expression in a time-dependent manner. Interestingly, activated Tfc cells, when incubated with B cells, presented rapid downregulation of perforin and granzyme B. In general, greater than 50% of tumor-infiltrating Tfc cells expressed CD40L. In addition, the level of CD40L in tumor-infiltrating Tfc cells was higher in stage IV CRC patients than in stage II and stage III CRC patients. Interestingly, the levels of perforin and granzyme B expression by tumor-infiltrating Tfc cells were inversely correlated with the level of CD40L expression by tumor-infiltrating Tfc cells. Overall, we demonstrated that an inverse association existed between CD40L and cytotoxic molecule expression in Tfc cells from CRC patients.


Assuntos
Adenocarcinoma , Ligante de CD40/genética , Neoplasias Colorretais , Granzimas/genética , Perforina/genética , Linfócitos T Citotóxicos/metabolismo , Adenocarcinoma/genética , Adenocarcinoma/imunologia , Adenocarcinoma/patologia , Adulto , Ligante de CD40/metabolismo , Antígenos CD8/genética , Antígenos CD8/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/patologia , Estudos de Casos e Controles , Neoplasias Colorretais/genética , Neoplasias Colorretais/imunologia , Neoplasias Colorretais/patologia , Citotoxicidade Imunológica/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Granzimas/metabolismo , Humanos , Linfócitos do Interstício Tumoral/metabolismo , Linfócitos do Interstício Tumoral/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Perforina/metabolismo , Receptores CXCR5/genética , Receptores CXCR5/metabolismo , Linfócitos T Citotóxicos/patologia
8.
Plant Dis ; 105(12): 3829-3834, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34152208

RESUMO

Rice blast caused by Magnaporthe oryzae poses significant threaten to rice production. For breeding and deploying resistant rice varieties, it is essential to understand the frequencies and genetic variations of avirulence (AVR) genes in the pathogen populations. In this study, 444 isolates were collected from Hunan Province, China in 2012, 2015, and 2016, and their pathogenicity was evaluated by testing them on monogenic rice lines carrying resistance genes Pita, Pizt, Pikm, Pib, or Pi9. The frequencies of corresponding AVR genes AVRPizt, AVRPikm, AVRPib, AVRPi9, and AVRPita were characterized by amplification and sequencing these genes in the isolates. Both Pi9 and Pikm conferred resistance to >75% of the tested isolates, while Pizt, Pita, and Pib were effective against 55.63, 15.31, and 3.15% of the isolates, respectively. AVRPikm and AVRPi9 were detected in 90% of the isolates and AVRPita, AVRPizt, and AVRPib were present in 26.12, 66.22, and 79% of the isolates, respectively. Sequencing of AVR genes showed that most mutations were single nucleotide polymorphisms, transposon insertions, and insertion mutations. The variable sites of AVRPikm and AVRPita were mainly located in the coding sequence regions (CDS), and most were synonymous mutations. A 494-bp Pot2 transposon sequence insertion was found at the 87 bp position upstream of the start codon in AVRPib. Noteworthy, although no mutations were found in CDS of AVRPi9, a GC-rich inserted sequence of ∼200 bp was found at the 1,272 bp position upstream of the start codon in three virulent isolates. As AVRPikm and AVRPi9 were widely distributed with low genetic variation in the pathogen population, Pikm and Pi9 should be promising genes for breeding rice cultivars with blast resistance in Hunan.


Assuntos
Genes Fúngicos , Magnaporthe , Oryza , Magnaporthe/genética , Oryza/microbiologia , Doenças das Plantas/microbiologia
9.
Environ Microbiol ; 22(7): 2843-2857, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32291878

RESUMO

Lipid droplets (LDs) serve as one of the major reservoirs in conidia of Magnaporthe oryzae and are quickly utilized during appressorium formation. Here, we identified a gene, LDP1, encoding a perilipin that is important for LD formation and utilization during appressorium maturation. LDP1 is highly expressed in conidium and immature appressorium. Disruption mutants of LDP1 were significantly reduced in virulence, due to appressorial turgor reduction and difficulty in penetration. LDs were significantly reduced in the Δldp1 mutant, indicating LDP1 was required for LDs formation. LDP1 was colocalized with the LDs in conidium and immature appressorium but was gradually separated during appressorium maturation. A typical intracellular triacylglycerol lipase, TGL1-2, was clearly separated with LDs in conidium and immature appressorium but was well colocalized with LDs during appressorium maturation. The subcellular localization of TGL1-2 was affected by LDP1. These data suggested that LDP1 was bound to LDs for protecting from utilization in conidia and at the early appressorium stage but was separated from LDs for lipase entering and degradation. LDP1 was phosphorylated by CPKA at Thr96, which was essential for its localization and functions. These data indicate perilipin LDP1 can coordinate LD formation and utilization for appressorium-mediated infection of M. oryzae.


Assuntos
Proteínas Fúngicas/metabolismo , Gotículas Lipídicas/metabolismo , Magnaporthe/metabolismo , Perilipina-1/metabolismo , Ascomicetos , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Lipase/metabolismo , Magnaporthe/genética , Mutação , Oryza/metabolismo , Perilipina-1/genética , Fosforilação , Doenças das Plantas/microbiologia , Esporos Fúngicos/metabolismo , Virulência/genética
10.
Environ Microbiol ; 22(7): 2581-2595, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32064718

RESUMO

Glycosylphosphatidylinositol (GPI) anchoring plays key roles in many biological processes by targeting proteins to the cell wall; however, its roles are largely unknown in plant pathogenic fungi. Here, we reveal the roles of the GPI anchoring in Magnaporthe oryzae during plant infection. The GPI-anchored proteins were found to highly accumulate in appressoria and invasive hyphae. Disruption of GPI7, a GPI anchor-pathway gene, led to a significant reduction in virulence. The Δgpi7 mutant showed significant defects in penetration and invasive growth. This mutant also displayed defects of the cell wall architecture, suggesting GPI7 is required for cell wall biogenesis. Removal of GPI-anchored proteins in the wild-type strain by hydrofluoric acid (HF) pyridine treatment exposed both the chitin and ß-1,3-glucans to the host immune system. Exposure of the chitin and ß-1,3-glucans was also observed in the Δgpi7 mutant, indicating GPI-anchored proteins are required for immune evasion. The GPI anchoring can regulate subcellular localization of the Gel proteins in the cell wall for appressorial penetration and abundance of which for invasive growth. Our results indicate the GPI anchoring facilitates the penetration of M. oryzae into host cells by affecting the cell wall integrity and the evasion of host immune recognition.


Assuntos
Ascomicetos/patogenicidade , Parede Celular/metabolismo , Glicosilfosfatidilinositóis/metabolismo , Oryza/microbiologia , Fosfotransferases/metabolismo , Ascomicetos/genética , Parede Celular/microbiologia , Quitina/metabolismo , Proteínas Fúngicas/genética , Glucanos/metabolismo , Ácido Fluorídrico/farmacologia , Hifas/metabolismo , Fosfotransferases/genética , Doenças das Plantas/microbiologia , Virulência
11.
J Exp Bot ; 71(6): 2112-2126, 2020 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-31986202

RESUMO

Genes that provide resistance to fungi and/or bacteria usually reduce plant growth and ultimately affect grain yield. Thus, crop breeding programs need to find genetic resources that balance disease resistance with growth. The receptor kinase FERONIA regulates cell growth and survival in Arabidopsis. Here, we investigate, in rice, the role of members of the FERONIA-like receptor (FLR) gene family in the balance between growth and the response to the fungal pathogen Magnaporthe oryzae (Pyricularia oryzae), which causes the most devastating disease in rice. We carried out genome-wide gene expression and functional screenings in rice via a gene knockout strategy, and we successfully knocked out 14 FLR genes in rice. Using these genetic resources, we found that mutations in the FLR2 and FLR11 genes provide resistance to rice blast without a profound growth penalty. Detailed analyses revealed that FLR2 mutation increased both defense-related gene expression and M. oryzae-triggered production of reactive oxygen species. Thus, our results highlight novel genetic tools for studying the underlying molecular mechanisms of enhancing disease resistance without growth penalty.


Assuntos
Magnaporthe , Oryza , Ascomicetos , Resistência à Doença/genética , Mutação , Oryza/genética , Melhoramento Vegetal , Doenças das Plantas/genética
12.
Chemotherapy ; 64(3): 146-154, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31715603

RESUMO

OBJECTIVE: Colorectal cancer (CRC) remains a major cause of cancer-related death worldwide. Proteasome 26S subunit ATPase 2 (PSMC2) plays vital roles in regulating cell cycle and transcription and has been confirmed to be a gene potentially associated with some human tumors. However, the expression correlation and molecular mechanism of PSMC2 in CRC are still unclear. This study aimed to investigate the role of PSMC2 in malignant behaviors in CRC. METHODS: The high protein levels of PSMC2 in CRC samples were identified by tissue microarray analysis. Lentivirus was used to silence PSMC2 in HCT116 and RKO cells; MTT and colony formation assay were performed to determine cell proliferation. Wound healing and Transwell assay were used to detect cell migration and invasion. Flow cytometry assay was applied to detect cell cycle and apoptosis. RESULT: The results showed that, among the 96 CRC patients, the expression of PSMC2 was a positive correlation with the clinicopathological features of the patients with CRC. Furthermore, the low PSMC2 expression group showed a higher survival rate than the high PSMC2 expression group. The expression levels of PSMC2 in cancer tissue were dramatically upregulated compared with adjacent normal tissues. In vitro, shPSMC2 was designed to inhibit the expression of PSMC2 in CRC cells. Compared with shCtrl, silencing of PSMC2 significantly suppressed cell proliferation, decreased single cell colony formation, enhanced apoptosis, and accelerated G2 phase and/or S phase arrest. CONCLUSION: Survival analysis indicated that high expression of PSMC2 in the CRC samples was associated with poorer survival rate than low expression of PSMC2, while the anti-tumor effect of PSMC2 silencing was also confirmed at the cellular level in vitro. Our results suggested that PSMC2 potentially worked as a regulator for CRC, and the silencing of PSMC2 may be a therapeutic strategy for CRC.


Assuntos
ATPases Associadas a Diversas Atividades Celulares/metabolismo , Apoptose , Proliferação de Células , Neoplasias Colorretais/patologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Interferência de RNA , ATPases Associadas a Diversas Atividades Celulares/antagonistas & inibidores , ATPases Associadas a Diversas Atividades Celulares/genética , Idoso , Linhagem Celular Tumoral , Movimento Celular , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/mortalidade , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Prognóstico , Complexo de Endopeptidases do Proteassoma/genética , RNA Interferente Pequeno/metabolismo , Pontos de Checagem da Fase S do Ciclo Celular
13.
New Phytol ; 219(3): 1031-1047, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29663402

RESUMO

Protein post-translational modifications play critical roles in cellular processes, development and stress response. The small ubiquitin-like modifier (SUMO) to proteins is one of the essential modifications in eukaryotes, but its function remains largely unknown in plant pathogenic fungi. We present a comprehensive analysis combined with proteomic, molecular and cellular approaches to explore the roles of sumoylation in the model plant fungal pathogen, Magnaporthe oryzae. We found the SUMO pathway plays key roles in colony growth, conidia formation and virulence to the host, as well as cell-cycle-related phenotypes. Sumoylation is also involved in responding to different stresses. Affinity purification identified 940 putative SUMO substrates, many of which were reported to be involved in development, stress response and infection. Interestingly, four septins were also shown to be sumoylated. Mutation of consensus sumoylation sites in each septin all resulted in reduced virulence to the host and dislocation of septins in appressoria. Moreover, sumoylation is also involved in extracellular secretion of different effector proteins. Our study on the functions of sumoylation provides novel insight into development and infection of the rice blast fungus.


Assuntos
Magnaporthe/patogenicidade , Oryza/microbiologia , Doenças das Plantas/microbiologia , Sumoilação , Ciclo Celular , Proteínas Fúngicas/metabolismo , Deleção de Genes , Genes de Plantas , Interações Hospedeiro-Patógeno , Hifas/crescimento & desenvolvimento , Magnaporthe/citologia , Magnaporthe/genética , Oryza/fisiologia , Reprodutibilidade dos Testes , Septinas/metabolismo , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/metabolismo , Estresse Fisiológico , Especificidade por Substrato , Sumoilação/genética , Virulência
14.
Microb Pathog ; 121: 40-44, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29752990

RESUMO

Crohn's disease (CD) is characterized by a pathogenic intestinal inflammation mediated by a Th1-skewed immune system and a dysregulated intestinal mucosal community. In this study, we investigated the role of bacteria on the activation and function of monocytes, and its association with CD pathogenesis. To this end, fecal bacteria from CD patients and healthy controls were collected and used to stimulate autologous circulating monocytes. Fecal bacteria from CD patients were more effective at upregulating NOD2, NLRP3, TLR2, and TLR4 expression than fecal bacteria from healthy controls. Furthermore, the monocyte-derived macrophages (MDMs) induced by CD bacteria were more sensitive to E. coli stimulation than the MDMs induced by control bacteria, and demonstrated more M1 characteristics with high IL-6, TNF-α, and IL-12 and low IL-4 production. These effects mediated by fecal bacteria from CD patients could be repressed by the supplementation of IL-4. IL-4 not only suppressed the expression of NOD1, NOD2, NLRP3, TLR2, TLR4, and CD14 in MDMs induced by CD bacteria, but also suppressed E. coli-mediated expression of IL-6, TNF-α, and IL-12. Furthermore, IL-4-conditioned MDMs were more effective at supporting Th2 differentiation and inhibiting Th1 and Th17 differentiation of CD4+ T cells. Together, these studies demonstrated that fecal bacteria from CD patients presented enhanced capacity to upregulate pattern-recognition molecules in macrophages, which could be repressed by IL-4.


Assuntos
Doença de Crohn/microbiologia , Fezes/microbiologia , Interleucina-4/metabolismo , Adulto , Estudos de Casos e Controles , Diferenciação Celular , Doença de Crohn/imunologia , Escherichia coli/metabolismo , Feminino , Regulação da Expressão Gênica , Humanos , Interleucina-12/genética , Interleucina-12/metabolismo , Interleucina-4/genética , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Macrófagos/metabolismo , Masculino , Pessoa de Meia-Idade , Monócitos/metabolismo , Monócitos/microbiologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Proteína Adaptadora de Sinalização NOD1/genética , Proteína Adaptadora de Sinalização NOD1/metabolismo , Proteína Adaptadora de Sinalização NOD2/genética , Proteína Adaptadora de Sinalização NOD2/metabolismo , Células Th1/citologia , Células Th17/citologia , Receptor 2 Toll-Like/genética , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Adulto Jovem
15.
Exp Cell Res ; 356(1): 57-63, 2017 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-28412245

RESUMO

Colorectal cancer is the third most prevalent cancer type worldwide and contributes to a significant percentage of cancer-related mortality. Recent studies have shown that the CXCR5+CD8+ T cells present more potent proinflammatory function than CXCR5-CD8+ T cells in chronic virus infections and in follicular lymphoma, but the role of CXCR5+CD8+ T cells in colorectal cancer is yet unclear. In this study, we demonstrated that CXCR5+CD8+ T cells were very rare in peripheral blood mononuclear cells from healthy and colorectal cancer individuals, but were significantly enriched in resected tumors and tumor-associated lymph nodes. Compared to CXCR5-CD8+ T cells, the CXCR5+CD8+ T cells demonstrated significantly higher Bcl-6 expression and lower Blimp1 expression, suggesting that CXCR5+CD8+ T cells might represent a memory CD8+ T cell subset. CXCR5+CD8+ T cells also enhanced the IgG expression by autologous B cells. Under ex vivo condition, the CXCR5+CD8+ T cells demonstrated lower degranulation, TNFα expression and IFNγ expression than CXCR5-CD8+ T cells. However, after PMA + ionomycin stimulation, the degranulation and TNFα expression by CXCR5+CD8+ T cells were significantly elevated to a level comparable with CXCR5-CD8+ T cells, whereas the IFNγ expression by PMA + ionomycin-stimulated CXCR5+CD8+ T cells were significantly higher than that by CXCR5-CD8+ T cells. Following long-term TCR-stimulation, CXCR5+CD8+ T cells demonstrated significantly more potent proliferation capacity and higher IFNγ expression than CXCR5-CD8+ T cells. TCR-stimulated CXCR5+CD8+ T cells also showed a gradual downregulation in CXCR5 expression. We further found that TCR-stimulated CXCR5+CD8+ T cells demonstrated higher granzyme B production and induced more specific lysis of autologous tumor cells than CXCR5-CD8+ T cells. Together, these data demonstrate that CXCR5+CD8+ T cells represent a significant CD8+ T cell subset in colorectal tumors and have the potential to contribute to antitumor immunity, but their specific roles require further studies in vivo.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Neoplasias Colorretais/imunologia , Imunoglobulina G/imunologia , Linfonodos/imunologia , Receptores CXCR5/metabolismo , Subpopulações de Linfócitos T/imunologia , Idoso , Linfócitos B/imunologia , Proliferação de Células , Granzimas/biossíntese , Humanos , Memória Imunológica/imunologia , Interferon gama/biossíntese , Ionomicina , Linfonodos/citologia , Pessoa de Meia-Idade , Fator 1 de Ligação ao Domínio I Regulador Positivo , Proteínas Proto-Oncogênicas c-bcl-6/biossíntese , Proteínas Repressoras/biossíntese , Acetato de Tetradecanoilforbol , Fator de Necrose Tumoral alfa/biossíntese
16.
Exp Cell Res ; 361(1): 135-140, 2017 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-29031634

RESUMO

Many studies have demonstrated that the inflamed mucosa of Crohn's disease (CD) patients presented a disturbed gut commensal community, and the shift in microbial composition and species variety is associated with disease severity. To establish a link between changes in the intestinal bacterial composition and the alteration of inflammation, we obtained fecal bacteria from CD patients and non-CD controls. The bacteria were then used to stimulate the peripheral blood mononuclear cells (PBMCs) from one non-CD individual. We found that the frequency of IFN-γ- and IL-17-expressing CD4 T cells was significantly higher after stimulation with CD bacteria than with non-CD bacteria, while the frequency of IL-4- and IL-10-expressing CD4 T cells was significantly decreased after stimulation with CD bacteria. A similar trend was observed in the level of cytokine expression and transcription expression. However, this difference was not clear-cut, as overlapping regions were observed between the two groups. With longer stimulation using CD bacteria, the skewing toward Th1/Th17 responses were further increased. This increase depended on the presence of monocytes/macrophages. Interestingly, we also found that B cells presented an inhibitory effect in CD bacteria-mediated skewing toward Th1/Th17 cells and promoted IL-10 secretion in CD bacteria-stimulated PBMCs. Together, our results demonstrated that CD bacteria could promote Th1/Th17 inflammation in a host factor-independent fashion.


Assuntos
Bactérias , Linfócitos T CD4-Positivos/imunologia , Doença de Crohn/imunologia , Fezes/microbiologia , Células Th1/imunologia , Células Th17/imunologia , Adolescente , Adulto , Idoso , Linfócitos B/imunologia , Linfócitos B/microbiologia , Linfócitos T CD4-Positivos/microbiologia , Estudos de Casos e Controles , Células Cultivadas , Doença de Crohn/microbiologia , Citocinas/metabolismo , Feminino , Humanos , Leucócitos Mononucleares , Masculino , Pessoa de Meia-Idade , Células Th1/microbiologia , Células Th17/microbiologia , Adulto Jovem
17.
Arterioscler Thromb Vasc Biol ; 36(9): 1868-78, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27444205

RESUMO

OBJECTIVE: AMP-activated protein kinase (AMPK), an energy and redox sensor, is activated in response to various cellular stresses, including hypoxia, nutrient deprivation, oxidative stress, and fluid shear stress at the site of vessel blockade. The activation of AMPK is involved in angiogenesis. However, it is unknown whether AMPK can influence arteriogenesis. Here, we demonstrate the contribution of macrophage AMPK to arteriogenesis and collateral remodeling and their underlying mechanisms in well-characterized in vivo and in vitro models. APPROACH AND RESULTS: AMPKα1, AMPKα2 knockout and wild-type littermates underwent femoral artery ligation. Collateral arteriogenesis was monitored in wild-type, global AMPKα1 knockout, or macrophage-specific AMPKα1 knockout mice, with or without hindlimb ligation. Compared with wild-type mice with ligation, global AMPKα1 knockout mice displayed significant reduction in blood flow recovery and impaired remodeling of collateral arterioles. Similar impairments were observed in macrophage-specific AMPK α1 knockout mice after hindlimb ligation. Mechanistically, we found that AMPKα1 promotes the production of growth factors, such as transforming growth factor ß, by directly phosphorylating the inhibitor of nuclear factor κB kinase alpha, resulting in an nuclear factor κB-dependent production of growth factors CONCLUSIONS: Our findings suggest a novel role for macrophage AMPKα1 in arteriogenesis and collateral remodeling and indicate that AMPKα1 activation might be beneficial for recovery from occlusive vascular disorders.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Circulação Colateral , Isquemia/enzimologia , Macrófagos/enzimologia , Músculo Esquelético/irrigação sanguínea , Neovascularização Fisiológica , Remodelação Vascular , Proteínas Quinases Ativadas por AMP/deficiência , Proteínas Quinases Ativadas por AMP/genética , Animais , Modelos Animais de Doenças , Ativação Enzimática , Genótipo , Células HEK293 , Membro Posterior , Humanos , Quinase I-kappa B/metabolismo , Isquemia/genética , Isquemia/fisiopatologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fenótipo , Fosforilação , Recuperação de Função Fisiológica , Fluxo Sanguíneo Regional , Transdução de Sinais , Fatores de Tempo , Fator de Transcrição RelA/metabolismo , Transfecção , Fator de Crescimento Transformador beta/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo
18.
Plant Dis ; 101(4): 557-561, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30677362

RESUMO

The blast (Magnaporthe oryzae) resistance (R) gene is the most economical and environmental method to control rice blast disease. Characterization of molecular identity and pathogenicity of M. oryzae benefits the deployment of effective blast R genes. In order to identify blast R genes that would be effective in Hunan Province,182 M. oryzae strains were analyzed with a Chinese differential system (CDS), repetitive element-based polymerase chain reaction (rep-PCR), and the presence and absence of avirulence (AVR) genes by PCR amplification with gene-specific primers. Identified blast R genes were validated with 24 monogenic lines (ML) carrying 24 major R genes. In total, 28 races (isolates) of M. oryzae was identified with CDS, and classified into 20 distinct groups with rep-PCR. Interestingly, AVR-Pia, AVR-Pik, AVR-Pizt, AVR-Pib, and AVR-Pi9 were detected in more than 86.8% of the isolates; AVR-Pita1 was in 51.3% and AVR-Pii was in only 2.5%. In contrast, pathogenicity assays on 24 ML demonstrated that Pi9, Piz5, Pikh, and Pikm were more effective, with resistant frequencies of 91.6, 91, 87.9, and 87.3%, respectively; Pia, Piks, Pit, Pi12, and Pib were less than 15%. These findings revealed the complexity of a genetic basis of rice blast resistance, and shed light on useful blast R genes in Hunan Province.

19.
Gastrointest Endosc ; 83(4): 800-7, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26341853

RESUMO

BACKGROUND AND AIMS: Colorectal laterally spreading tumors (LSTs) are divided into homogeneous (LST-G-H), nodular mixed (LST-G-M), flat elevated (LST-NG-F), and pseudodepressed (LST-NG-PD) subtypes. We hypothesized that based on the rates of advanced histology, the recurrence rates of the LST-NG-PD and LST-G-M groups may be higher than those of the other subgroups. METHODS: Endoscopic submucosal dissection (ESD) was performed in 156 patients with a total of 177 LSTs. The clinicopathological features and long-term prognosis of ESD according to specific subtype were investigated. RESULTS: LSTs were most commonly found in the rectum, and the highest percentage of rectal lesions was observed in the LST-G-M group (71.1% vs overall 55.4%, P = .032). The LST-G-M lesions were larger (60 ± 22 mm vs 40 ± 33 mm, P = .034) than the LST-G-H lesions. The LST-G-M group also demonstrated more high-grade intraepithelial neoplasias (32.2% vs 10.8%, P = .003) and submucosal carcinomas (13.6% vs 1.5%, P = .010) compared with the LST-G-H group. The LST-NG-PD group exhibited the highest incidence of submucosally invasive cancer (16.7%). The overall perforation rate was 2.3%. The perforation rate in the LST-NG group was higher than that in the LST-G group (5.7% vs 0.8%, P = .047). All recurrences (7.7%) were found by colonoscopy without any detection of cancers, and no difference was found among the subtypes. CONCLUSIONS: No significant differences were observed among subgroups with 44.4 ± 16.3 months of follow-up. Considering that all recurrences were discovered by colonoscopy and most could be cured by repeated ESD, the LSTs of all subgroups require more intensive follow-up compared with smaller adenomatous lesions.


Assuntos
Carcinoma in Situ/patologia , Carcinoma in Situ/cirurgia , Neoplasias do Colo/patologia , Neoplasias do Colo/cirurgia , Recidiva Local de Neoplasia/patologia , Neoplasias Retais/patologia , Neoplasias Retais/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Colonoscopia , Dissecação/efeitos adversos , Feminino , Seguimentos , Humanos , Mucosa Intestinal/patologia , Mucosa Intestinal/cirurgia , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Fatores de Tempo
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