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1.
J Med Chem ; 67(9): 7283-7300, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38676656

RESUMO

The epidermal growth factor receptor (EGFR) tertiary C797S mutation is an important cause of resistance to Osimertinib, which seriously hinders the clinical application of Osimertinib. Developing proteolysis-targeting chimeras (PROTACs) targeting EGFR mutants can offer a promising strategy to overcome drug resistance. In this study, some novel PROTACs targeting C797S mutation were designed and synthesized based on a new EGFR inhibitor and displayed a potent degradation effect in H1975-TM cells harboring EGFRL858R/T790M/C797S. The representative compound C6 exhibited a DC50 of 10.2 nM against EGFRL858R/T790M/C797S and an IC50 of 10.3 nM against H1975-TM. Furthermore, C6 also showed potent degradation activity against various main EGFR mutants, including EGFRDel19/T790M/C797S. Mechanistic studies revealed that the protein degradation was achieved through the ubiquitin-proteasome system. Finally, C6 inhibited tumor growth in the H1975-TM xenograft tumor model effectively and safely. This study identifies a novel and potent EGFR PROTAC to overcome Osimertinib resistance mediated by C797S mutation.


Assuntos
Antineoplásicos , Desenho de Fármacos , Receptores ErbB , Mutação , Inibidores de Proteínas Quinases , Proteólise , Receptores ErbB/metabolismo , Receptores ErbB/genética , Receptores ErbB/antagonistas & inibidores , Humanos , Animais , Proteólise/efeitos dos fármacos , Linhagem Celular Tumoral , Antineoplásicos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Camundongos , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Camundongos Nus , Acrilamidas/farmacologia , Acrilamidas/síntese química , Acrilamidas/química , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto , Proliferação de Células/efeitos dos fármacos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/genética , Compostos de Anilina/farmacologia , Compostos de Anilina/síntese química , Compostos de Anilina/química , Camundongos Endogâmicos BALB C , Relação Estrutura-Atividade , Quimera de Direcionamento de Proteólise , Indóis , Pirimidinas
2.
J Fungi (Basel) ; 10(2)2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38392805

RESUMO

Bipolaris maydis partitivirus 36 (BmPV36) is a mycovirus that can significantly reduce the virulence of the host Bipolaris maydis, but its hypovirulence mechanism is not clear. To investigate the response of B. maydis to BmPV36, the effects of BmPV36 on host cell structure and gene expression were studied via transmission electron microscopy and transcriptome sequencing using BmPV36-carrying and virus-free mycelium on the second and fifth culture. The results of transmission electron microscopy showed that the cell wall microfibrils of B. maydis were shortened, the cell membrane was broken, and membrane-bound vesicles and vacuoles appeared in the cells after carrying BmPV36. Transcriptome sequencing results showed that after carrying BmPV36, B. maydis membrane-related genes were significantly up-regulated, but membrane transport-related genes were significantly down-regulated. Genes related to carbohydrate macromolecule polysaccharide metabolic and catabolic processes were significantly down-regulated, as were genes related to the synthesis of toxins and cell wall degrading enzymes. Therefore, we speculated that BmPV36 reduces the virulence of B. maydis by destroying the host's cell structure, inhibiting the synthesis of toxins and cell wall degrading enzymes, and reducing cell metabolism. Gaining insights into the hypovirulence mechanism of mycoviruses will provide environmentally friendly strategies for the control of fungal diseases.

3.
Vet Microbiol ; 288: 109923, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38061277

RESUMO

Escherichia coli and Salmonella Typhimurium are the main pathogens of diarrhea in weaned piglets. The prevention of bacterial diarrhea in weaned piglets by phage is rarely reported. We conducted this study to evaluate the preventive effect of phages on mixed Escherichia coli and Salmonella Typhimurium infections in weaned piglets. A novel phage named NJ12 was isolated by using Salmonella Typhimurium SM022 as host bacteria and characterized by electron microscopy, genomic analysis and in vitro bacteriostatic activity. Phage NJ12 and a previously reported phage EP01 were microencapsulated with sodium alginate to make phage cocktail. Microencapsulated phage cocktail and PBS (Phosphate buffer solution) were used to piglets the phage and phage-free group through oral administration before bacterial infection 2 h, respectively. Piglets of the phage and phage-free group were consumed with feed contaminated with 6 mL (108CFU/mL) Escherichia coli O157:H7 GN07 (GXEC-N07) and 6 mL (108CFU/mL) SM022 every day for seven consecutive days. The results showed that piglets in the phage-free group had more severe diarrhea, larger decreased average weight gain and higher levels of neutrophils compared with piglets in phage group. Meanwhile, piglets in the phage-free group had higher load of SM022 and GN07 in jejunal tissue and more severe intestinal damage compared with piglets in group phage in vivo. In addition, oral administration phage can significant decreased the relative abundance of Enterobacteriaceae but hardly repaired the changes of diversity and composition of gut microbiota caused by the mixed infection of SM022 and GN07. This implies that phage used as a feed additive have a marvelous preventive effect on bacterial diarrhea during weaning of piglets.


Assuntos
Bacteriófagos , Disenteria , Infecções por Escherichia coli , Escherichia coli O157 , Infecções por Salmonella , Doenças dos Suínos , Animais , Suínos , Salmonella typhimurium , Escherichia coli O157/genética , Desmame , Diarreia/prevenção & controle , Diarreia/veterinária , Diarreia/microbiologia , Infecções por Escherichia coli/prevenção & controle , Infecções por Escherichia coli/veterinária , Infecções por Escherichia coli/microbiologia , Disenteria/veterinária , Doenças dos Suínos/prevenção & controle , Doenças dos Suínos/microbiologia
4.
J Med Chem ; 66(21): 14633-14652, 2023 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-37885208

RESUMO

Epidermal growth factor receptor (EGFR)-activating mutation is an important oncogenic driver of nonsmall cell lung cancer (NSCLC) patients. Osimertinib has been the first-line treatment for EGFR-mutated NSCLC. However, the tertiary C797S mutation leads to Osimertinib resistance by blocking the covalent binding of Cys797 to Osimertinib. To date, there are no approved inhibitors for the treatment of Osimertinib resistance. Herein, we identified a novel lead compound S8 targeting EGFRL858R/T790M/C797S by structure-based virtual screening and synthesized a series of novel compounds. Representative compound C34 showed potent inhibitory activity against EGFRL858R/T790M/C797S with an IC50 of 5.1 nM and significantly inhibited the proliferation of the H1975-TM cell line harboring EGFRL858R/T790M/C797S with an IC50 of 0.05 µM. Additionally, compound C34 demonstrated good pharmacokinetic properties with an oral bioavailability of 30.72% and significantly inhibited tumor growth in the H1975-TM xenograft tumor model. This study provides a novel thiazole derivative as an EGFR inhibitor to overcome C797S-mediated resistance.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Pulmonares/metabolismo , Receptores ErbB/metabolismo , Mutação , Resistencia a Medicamentos Antineoplásicos , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Inibidores de Proteínas Quinases/química , Compostos de Anilina/farmacologia , Linhagem Celular Tumoral
5.
BMC Vet Res ; 19(1): 165, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37730566

RESUMO

BACKGROUND: Escherichia coli (E. coli) is a common pathogen that often causes diarrhea in piglets. Since bacteria are becoming more and more resistant to antibiotics, phages have become a promising alternative therapy. However, the therapy of oral phage often fails to achieve the desired effect. A novel phage named A221 was isolated by using E. coli GXXW-1103 as host strain, characterized by electron microscopy, genomic sequencing and analyzed by measuring lysis ability in vitro. RESULTS: Phage A221 was identified as a member of Ackermannviridae, Aglimvirinae, Agtrevirus with 153297 bp genome and effectively inhibited bacterial growth in vitro for 16 h. This study was conducted to evaluate the therapeutic effect of oral microencapsulated phage A221 on E. coli GXXW-1103 infections in weaned piglets. The protective effect of phage was evaluated by body weight analysis, bacterial load and histopathological changes. The results showed that with the treatment of phage A221, the body weight of piglets increased, the percentage of Enterobacteriaceae in duodenum decreased to 0.64%, the lesions in cecum and duodenum were alleviated, and the bacterial load in the jejunal lymph nodes, cecum and spleen were also significantly different with infected group (P < 0.001). CONCLUSIONS: The results showed that phage A221 significantly increased the daily weight gain of piglets, reduced the bacterial load of tissues and the intestinal lesions, achieved the same therapeutic effect as antibiotic Florfenicol. Taken together, oral microencapsulated phage A221 has a good therapeutic effect on bacterial diarrhea of weaned piglets, which provides guidance for the clinical application of phage therapy in the future.


Assuntos
Bacteriófagos , Infecções por Escherichia coli , Terapia por Fagos , Doenças dos Suínos , Animais , Suínos , Escherichia coli , Terapia por Fagos/veterinária , Infecções por Escherichia coli/terapia , Infecções por Escherichia coli/veterinária , Diarreia/terapia , Diarreia/veterinária , Antibacterianos/uso terapêutico , Peso Corporal , Doenças dos Suínos/terapia
6.
ACS Nano ; 17(18): 18164-18177, 2023 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-37703316

RESUMO

Reperfusion injury presents a significant obstacle to neuronal survival following successful recanalization in ischemic stroke, which is characterized by intricate pathophysiological processes comprising numerous interconnected pathways. Oxidative stress-induced neuronal ferroptosis and the overactivation of glial cells play important roles in this phenomenon. In this study, we developed a targeted cross-linked micelle loaded with idebenone to rescue the ischemic penumbra by inhibiting neuronal ferroptosis and glial overactivation. In rat models, the CREKA peptide-modified micelles accumulate in the damaged brain via binding to microthrombi in the ipsilateral microvessels. Upon reactive oxygen species (ROS) stimulation, diselenide bonds within the micelles are transformed to hydrophilic seleninic acids, enabling synchronized ROS consumption and responsive drug release. The released idebenone scavenges ROS, prevents oxidative stress-induced neuronal ferroptosis, attenuates glial overactivation, and suppresses pro-inflammatory factors secretion, thereby modulating the inflammatory microenvironment. Finally, this micelle significantly reinforces neuronal survival, reduces infarct volume, and improves behavioral function compared to the control groups. This pleiotropic therapeutic micelle provides a proof-of-concept of remodeling the lesion microenvironment by inhibiting neuronal ferroptosis and glial overactivation to treat cerebral ischemia-reperfusion injury.


Assuntos
Ferroptose , Traumatismo por Reperfusão , Animais , Ratos , Micelas , Espécies Reativas de Oxigênio , Neuroglia , Traumatismo por Reperfusão/tratamento farmacológico
7.
Acta Biomater ; 167: 387-400, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37276955

RESUMO

The tumor microenvironment of pancreatic ductal adenocarcinoma (PDAC) is the main block for the penetration of chemotherapy. In the tumor microenvironment, a dense matrix composed of fibrin is formed on the exterior, while the interior is featured by high reduction, hypoxia and low pH. How to match the special microenvironment to on-demand drug release is the key to improve chemotherapeutic efficacy. Herein, a microenvironment-responsive micellar system is developed to deepen tumoral penetration. Briefly, the conjugation of a fibrin-targeting peptide to PEG-poly amino acid has been utilized to achieve accumulation of micelles in the tumor stroma. By modification of micelles with hypoxia-reducible nitroimidazole which becomes protonated under acidic conditions, their surface charge is more positive, facilitating deeper penetration into tumors. Paclitaxel was loaded onto the micelles via a disulfide bond to enable glutathione (GSH)-responsive release. Therefore, the immunosuppressive microenvironment is relived through the alleviation of hypoxia and depletion of GSH. Hopefully, this work could establish paradigms by designing sophisticated drug-delivery systems to tactfully employ and retroact the tamed tumoral microenvironment to improve the therapeutic efficacy based on understanding the multiple hallmarks and learning the mutual regulation. STATEMENT OF SIGNIFICANCE: Tumor microenvironment(TME) is an unique pathological feature of pancreatic cancer and an inherent barrier to chemotherapy. Numerous studies regard TME as the targets for drug delivery. In this work, we propose a hypoxia-responsive nanomicellar drug delivery system that aiming hypoxia TME of pancreatic cancer. The nanodrug delivery system could respond to the hypoxic microenvironment and enhance the penetration of the inner tumor at the same time preserving the outer tumor stroma, thus achieving targeted treatment of PDAC by preserving the integrity of the outer stroma. Simultaneously, the responsive group can reverse the degree of hypoxia in TME by disrupting the redox balance in the tumor region, thus achieving precise treatment of PDAC by matching the pathological characteristics of TME. We believe our article would provide new design ideas for the future treatments for pancreatic cancer.


Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Humanos , Micelas , Microambiente Tumoral , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Carcinoma Ductal Pancreático/patologia , Hipóxia , Glutationa , Terapia de Imunossupressão , Linhagem Celular Tumoral , Neoplasias Pancreáticas
8.
Front Microbiol ; 14: 1143480, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37065114

RESUMO

Excessive fertilization is associated with nutrient loss, soil compaction, and weak plant resistance. Straw returning can increase soil fertility with a consequent reduction in fertilizer, but the effects of fertilizer reduction coupled with straw returning on crop endophytic microbes and crop disease are poorly understood. Therefore, using metagenomic sequencing methods we investigated the responses of soil fertility, diversity, the function of root endophytic bacteria, and the occurrence of wheat crown rot due to the application of fertilizer (no, moderate and excessive fertilizer) coupled with or without straw returning after 7 years of treatments. The results showed that, after excessive fertilization, the wheat crown rot became severe, registering a disease index of 23. Compared with excessive fertilization, moderate fertilization coupled with straw returning significantly reduced the incidence of wheat crown rot, the disease index was reduced by 38.50%, and the richness and diversity of endophytic bacteria were increased by 61.20 and 11.93%, respectively, but the soil fertility was not significantly affected. In addition, moderate fertilization coupled with straw returning changed the community structure of endophytic bacteria and increased the relative abundance of carbohydrate metabolism and nitrogen fixation-related genes by 4.72 and 9.32%, respectively. Our results indicated that fertilizer reduction coupled with straw returning reduced the occurrence of wheat crown rot, increased the diversity of endophytic bacteria, and changed the community structure and function of endophytic bacteria, which will provide a better understanding of the interaction of fertilization coupled with straw returning, endophytic bacteria and wheat crown rot.

9.
Front Plant Sci ; 14: 1132507, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36909432

RESUMO

Fusarium pseudograminearum is a soil-borne pathogen that is capable of causing a highly destructive crown disease in wheat. Secondary metabolites (SMs), especially deoxynivalenol (DON), are the primary virulence factors during infection. Here, we characterised the global regulator FpLaeB, an orthologue of LaeB protein function, to regulate the SM in Aspergillus nidulans. Through the utility of the gene targeting approach, we found that the vegetative growth of the FpLaeB deletion mutant was drastically reduced compared to that of the wild type. FpLaeB was also important for conidiation because the FpLaeB deletion mutant formed fewer conidia in induced medium. In addition, the sensitivity of the FpLaeB deletion mutant to the cell wall integrity inhibitor was decreased, while its growth was more severely inhibited by the cell membrane inhibitor sodium dodecyl sulfate (SDS) than that of the wild type. More importantly, the virulence was decreased when the FpLaeB deletion mutant was inoculated onto the wheat stem base or head. Through genome-wide gene expression profiling, FpLaeB was found to regulate several processes related to the above phenotypes such as the carbohydrate metabolic process, which is an integral and intrinsic component of membranes, especially SMs. Furthermore, the generation of DON was impaired in the FpLaeB deletion mutant via ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) assay. These results showed that FpLaeB plays an important role in the growth, development, and maintenance of the cell wall, and in membrane integrity. More importantly, FpLaeB is required for SMs and full virulence in F. pseudograminearum.

10.
Virus Genes ; 59(2): 302-311, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36701048

RESUMO

Escherichia coli is a common conditional pathogen, for which antibiotic therapy is considered an effective treatment. The imprudent use of antibiotics has led to the increase of multiple-antibiotic-resistant E. coli species. With the incidence of antibiotic resistance reaching a crisis point, it is imperative to find alternative treatments for multidrug-resistant infections. Using phage for pathogen control is a promising treatment option to combat bacterial resistance. In this study, a novel virulent Podoviridae phage Kayfunavirus TM1 infecting Escherichia coli was isolated from pig farm sewage in Guangxi, China. The one-step growth curve with the optimal multiplicity of infection of 0.01 revealed a latent period of 10 min and a burst size of 50 plaque-forming units per cell. The stability test reveals that it is stable from 4 to 60 °C and pH from 3 to 11. The double-stranded DNA genome of phage Kayfunavirus TM1 is composed of 39,948 base pairs with a GC content of 50.03%.


Assuntos
Bacteriófagos , Suínos , Animais , Bacteriófagos/genética , Escherichia coli/genética , Genoma Viral , DNA Viral/genética , China , Antibacterianos
11.
Bioelectrochemistry ; 150: 108345, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36495704

RESUMO

Escherichia coli (E. coli) O157:H7 is one of the most important foodborne pathogens that causing severe foodborne diseases. With the development of foodborne diseases, there is an urgent need to seek new methods for early detection and monitoring of E. coli O157:H7. In this study, an electrochemical biosensor using phage EP01 as the recognition agent for detection of E. coli O157:H7 GXEC-N07 was established due to the specificity and high efficiency of phage EP01 in recognizing GXEC-N07. The biosensor was developed by depositing phages conjugated carboxyl graphene oxide (CFGO) and conductive carbon black (CB) onto the surface of glass carbon electrodes (GCEs). When detecting GXEC-N07 in the concentration range of 102 âˆ¼ 107 CFU/mL, the biosensor showed good linearity with a low detection limit of 11.8 CFU/mL, and the whole progress was in less than 30 min. The biosensor was successfully applied to the quantitative detection of GXEC-N07 in fresh milk and raw pork. The recovery values ranged from 60.8 % to 114.2 %. The biosensor provides a rapid, specific, low cost, and label free tool for E. coli O157:H7 GXEC-N07 detection. It is expected to become a powerful method for the detection of bacteria that threatening food safety and public health security.


Assuntos
Bacteriófagos , Técnicas Biossensoriais , Escherichia coli O157 , Doenças Transmitidas por Alimentos , Humanos , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Técnicas Biossensoriais/métodos , Doenças Transmitidas por Alimentos/microbiologia
12.
Virus Genes ; 58(5): 448-457, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35716226

RESUMO

Escherichia coli, a gram-negative bacterium, was generally considered conditional pathogenic bacteria and the proportion of bacteria resistant to commonly used specified antibacterial drugs exceeded 50%. Phage therapeutic application has been revitalized since antibiotic resistance in bacteria was increasing. Compared with antibiotics, phage is the virus specific to bacterial hosts. However, further understanding of phage-host interactions is required. In this study, a novel phage specific to a E. coli strain, named as phage Kayfunavirus ZH4, was isolated and characterized. Transmission electron microscopy showed that phage ZH4 belongs to the family Autographiviridae. The whole-genome analysis showed that the length of phage ZH4 genome was 39,496 bp with 49 coding domain sequence (CDS) and no tRNA was detected. Comparative genome and phylogenetic analysis demonstrated that phage ZH4 was highly similar to phages belonging to the genus Kayfunavirus. Moreover, the highest average nucleotide identity (ANI) values of phage ZH4 with all the known phages was 0.86, suggesting that ZH4 was a relatively novel phage. Temperature and pH stability tests showed that phage ZH4 was stable from 4° to 50 °C and pH range from 3 to 11. Host range of phage ZH4 showed that there were only 2 out of 17 strains lysed by phage ZH4. Taken together, phage ZH4 was considered as a novel phage with the potential for applications in the food and pharmaceutical industries.


Assuntos
Bacteriófagos , Caudovirales , Antibacterianos , Bacteriófagos/genética , Caudovirales/genética , Colífagos/genética , Escherichia coli/genética , Genoma Viral , Nucleotídeos , Filogenia
13.
J Am Chem Soc ; 144(22): 9564-9569, 2022 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-35623059

RESUMO

Here we report an asymmetric formal nucleophilic o-cresolylation reaction with the Morita-Baylis-Hillman (MBH) carbonates from 2-cyclohexanones and diverse aldehydes under palladium catalysis, by in situ generation of electron-neutral and HOMO-raised η2-Pd(0)-dienone complexes via an oxidative insertion/π-σ-isomerization/ß-H elimination activation sequence. The subsequent umpolung vinylogous addition to a variety of imines is realized upon Pd(0)-mediated π-Lewis base catalysis, finally furnishing o-cresolylated products followed by another cascade of a π-σ-isomerization/ß-H elimination/aromatization process. Moderate to excellent diastereo- and enantioselectivity are achieved for substantial substrate assemblies by employing a newly designed bulky chiral phosphonamidite ligand, and the resultant multifunctional products can be facilely elaborated to access diverse enantioenriched architectures. In addition, the catalytic reaction pathway is finely illuminated by control experiments.


Assuntos
Cicloexanonas , Paládio , Carbonatos/química , Catálise , Estrutura Molecular , Paládio/química , Estereoisomerismo
14.
Environ Microbiome ; 17(1): 17, 2022 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-35387674

RESUMO

BACKGROUND: As genetic entities infecting and replicating only in bacteria, bacteriophages can regulate the community structure and functions of their host bacteria. The ecological roles of bacteriophages in aquatic and forest environments have been widely explored, but those in agroecosystems remains limited. Here, we used metagenomic sequencing to analyze the diversity and interactions of bacteriophages and their host bacteria in soils from three typical rice agroecosystems in China: double cropping in Guangzhou, southern China, rice-wheat rotation cropping in Nanjing, eastern China and early maturing single cropping in Jiamusi, northeastern China. Enterobacter phage-NJ was isolated and its functions on soil nitrogen cycling and effect on soil bacterial community structure were verified in pot inoculation experiments and 16S rRNA gene sequencing. RESULTS: Soil bacterial and viral diversity and predicted functions varied among the three agroecosystems. Genes detected in communities from the three agroecosystems were associated with typical functions: soil bacteria in Jiamusi were significantly enriched in genes related to carbohydrate metabolism, in Nanjing with xenobiotics biodegradation and metabolism, and in Guangzhou with virulence factors and scarce in secondary metabolite biosynthesis, which might lead to a significant occurrence of rice bacterial diseases. The virus community structure varies significantly among the three ecosystems, only 13.39% of the total viral species were shared by the three rice agroecosystems, 59.56% of the viral species were specific to one agroecosystem. Notably, over-represented auxiliary carbohydrate-active enzyme (CAZyme) genes were identified in the viruses, which might assist host bacteria in metabolizing carbon, and 67.43% of these genes were present in Jiamusi. In bacteriophage isolation and inoculation experiments, Enterobacter bacteriophage-NJ reduced the nitrogen fixation capacity of soil by lysing N-fixing host bacteria and changed the soil bacterial diversity and community structure. CONCLUSION: Our results showed that diversity and function predicted of paddy soil bacteria and viruses varied in the three agroecosystems. Soil bacteriophages can affect nutrient cycling by boosting host metabolism through the carried auxiliary metabolic genes (AMGs) and lysing the host bacteria that are involved in biogeochemical cycles. These findings form a basis for better understanding bacterial and bacteriophage diversity in different rice agroecosystems, laying a solid foundation for further studies of soil microbial communities that support ecofriendly production of healthy rice.

16.
Plant Dis ; 105(9): 2575-2584, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33404273

RESUMO

On the North China Plain, one of the most water-deficient regions in China, bare fallow has been implemented over a large-scale area to conserve water during the growth season of water-intensive winter wheat since 2015. However, the effects of this bare fallow on fungal community and the occurrence of crop diseases are poorly understood. Here we measured soil chemical properties, fungal community composition, and the occurrence of crop diseases after 15 years of long-term fallow (continuous maize or soybean) and non-fallow (maize-wheat rotation; soybean-wheat rotation) cropping systems. Bare fallow during the winter-wheat growth season significantly decreased soil organic matter, available nitrogen, and phosphorus. It also changed the composition of soil fungal communities, i.e., increased relative abundances of some potentially pathogenic species of Lectera, Fusarium, and Volutella but decreased beneficial Cladorrhium and Schizothecium. Meanwhile, the epidemic tendency of maize diseases changed correspondingly: the disease index of southern corn leaf blight and maize brown spot increased, but the incidence of stalk rot decreased compared with the non-fallow system. Soybean diseases were very mild regardless of the cropping system during the total experimental period. Network analysis demonstrated that the soil fungal diversity associated with maize diseases was affected by the decreased soil organic matter and available nitrogen and phosphorus. Our results suggest that bare fallow in the winter-wheat season affected the soil chemical properties, fungal community, and the occurrence of maize fungal diseases.


Assuntos
Micobioma , Micoses , Fertilizantes/análise , Estações do Ano , Solo , Triticum , Zea mays
17.
Front Microbiol ; 11: 581203, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33250871

RESUMO

Apple Valsa canker is a destructive disease caused by the ascomycete Valsa mali and poses a serious threat to apple production. Toxins synthesized by secondary metabolite biosynthetic gene clusters (SMBGCs) have been proven to be crucial for pathogen virulence. A previous study showed that V. mali genome contains remarkably expanded SMBGCs and some of their genes were significantly upregulated during infection. In this study, we focus on LaeA, a known regulator of secondary metabolism, for its role in SMBGC regulation, toxin production, and virulence of V. mali. Deletion of VmLaeA led to greatly reduced virulence with lesion length reduced by 48% on apple twigs. Toxicity tests proved that toxicity of secondary metabolites (SMs) produced by VmLaeA deletion mutant (ΔVmlaeA) was markedly decreased in comparison with wild-type (WT). Transcriptomic and proteomic analyses of WT and ΔVmlaeA indicated that a portion of transporters and about half (31/60) SMBGCs are regulated by VmLaeA. Function analysis of eight gene clusters including PKS7, PKS11, NRPS14, PKS16, PKS23, PKS31, NRPS/PKS33, and PKS39 that were differentially expressed at both transcriptional and translational levels showed that four of them (i.e., PKS11, PKS16, PKS23, and PKS31) were involved in pigment production and NRPS14 contributed to virulence. Our findings will provide new insights and gene resources for understanding the role of pathogenicity-related toxins in V. mali.

18.
J Neurosci ; 39(46): 9130-9144, 2019 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-31604834

RESUMO

Neuropathic pain is one of the most common and notorious neurological diseases. The changes in cerebral structures after nerve injury and the corresponding contributions to neuropathic pain are not well understood. Here we found that the majority of glutamatergic neurons in the area 2 of midcingulate cortex (MCC Cg2Glu) were inhibited by painful stimulation in male mice. Optogenetic manipulation revealed that these neurons were tonically involved in the inhibitory modulation of multimodal nociception. We further identified the projections to GABAergic neurons in the zona incerta (ZIGABA) mediated the pain inhibitory role. However, MCC Cg2Glu became hypoactive after nerve injury. Although a brief activation of the MCC Cg2Glu to ZIGABA circuit was able to relieve the aversiveness associated with spontaneous ongoing pain, consecutive activation of the circuit was required to alleviate neuropathic allodynia. In contrast, glutamatergic neurons in the area 1 of MCC played opposite roles in pain modulation. They became hyperactive after nerve injury and only consecutive inhibition of their activity relieved allodynia. These results demonstrate that MCC Cg2Glu constitute a component of intrinsic pain inhibitory circuitry and their hypoactivity underlies neuropathic pain. We propose that selective and persistent activation of the MCC Cg2Glu to ZIGABA circuit may serve as a potential therapeutic strategy for this disease.SIGNIFICANCE STATEMENT Glutamatergic neurons in the area 2 of midcingulate cortex (MCC Cg2Glu) are tonically involved in the intrinsic pain inhibition via projecting to GABAergic neurons in the zona incerta. They are hypoactive after nerve injury. Selective activation of the circuit compensates the reduction of its analgesic strength and relieves neuropathic pain. Therefore, MCC Cg2Glu and the related analgesic circuit may serve as therapeutic targets for neuropathic pain. In contrast, MCC Cg1Glu have an opposite role in pain modulation and become hyperactive after nerve injury. The present study provides novel evidence for the concept that neuropathic pain is associated with the dysfunction of endogenous pain modulatory system and new perspective on the treatment of neuropathic pain.


Assuntos
Neurônios GABAérgicos/fisiologia , Giro do Cíngulo/fisiopatologia , Neuralgia/fisiopatologia , Dor/fisiopatologia , Zona Incerta/fisiopatologia , Animais , Masculino , Camundongos Endogâmicos C57BL , Vias Neurais/fisiologia , Optogenética , Percepção da Dor/fisiologia
19.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 48(3): 310-317, 2019 05 25.
Artigo em Chinês | MEDLINE | ID: mdl-31496164

RESUMO

The habenula is a small and bilateral nucleus above dorsal thalamus, which contains several different types of neurons. The habenula has extensive connections with the forebrain, septum and monoaminergic nuclei in the midbrain and brainstem. Habenula is known as an 'anti-reward' nucleus, which can be activated by aversive stimulus and negative reward prediction errors. Accumulating researchs have implicated that the habenula is involved in several behaviors crucial to survival. Meanwhile, the roles of the habenula in neuropsychiatric diseases have received increasing attention. This review summaries the studies regarding the roles of habenula and the related circuits in neuropathic pain, depression, drug addiction and schizophrenia, and discusses the possibility to use the habenula as a treatment target.


Assuntos
Transtorno Depressivo , Habenula , Humanos , Transtornos Mentais/patologia , Mesencéfalo , Neurônios/metabolismo , Recompensa
20.
New Phytol ; 222(2): 995-1011, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30537041

RESUMO

Pathogen-associated molecular patterns (PAMPs) are conserved molecules that are crucial for normal life cycle of microorganisms. However, the diversity of microbial PAMPs is little known. During screening of cell-death-inducing factors from the necrotrophic fungus Valsa mali, we identified a novel PAMP VmE02 that is widely spread in oomycetes and fungi. Agrobacterium tumefaciens-mediated transient expression or infiltration of recombinant protein produced by Escherichia coli was performed to assay elicitor activity of the proteins tested. Virus-induced gene silencing in Nicotiana benthamiana was used to determine the components involved in VmE02-triggered cell death. The role of VmE02 in virulence and conidiation of V. mali were characterized by gene deletion and complementation. We found that VmE02, together with some of its homologues from both oomycete and fungal species, exhibited cell-death-inducing activity in N. benthamiana. VmE02-triggered cell death was shown to be dependent on BRI1-ASSOCIATED KINASE-1, SUPPRESSOR OF BIR1-1, HSP90 and SGT1 in N. benthamiana. Deletion of VmE02 in V. mali greatly attenuated pathogen conidiation but not virulence, and treatment of N. benthamiana with VmE02 enhances plant resistance to Sclerotinia sclerotiorum and Phytophthora capsici. We conclude that VmE02 is a novel cross-kingdom PAMP produced by several fungi and oomycetes.


Assuntos
Proteínas Fúngicas/metabolismo , Moléculas com Motivos Associados a Patógenos/metabolismo , Ascomicetos/metabolismo , Morte Celular , Regulação da Expressão Gênica de Plantas , Oomicetos/metabolismo , Filogenia , Imunidade Vegetal , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Esporos Fúngicos/fisiologia , Nicotiana/citologia , Nicotiana/genética , Nicotiana/imunologia , Nicotiana/microbiologia
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