RESUMO
Uropathogenic Escherichia coli (UPEC) is the most common causative agent of urinary tract infection (UTI). UPEC invades bladder epithelial cells (BECs) via fusiform vesicles, escapes into the cytosol, and establishes biofilm-like intracellular bacterial communities (IBCs). Nucleoside-diphosphate kinase (NDK) is secreted by pathogenic bacteria to enhance virulence. However, whether NDK is involved in UPEC pathogenesis remains unclear. Here, we find that the lack of ndk impairs the colonization of UPEC CFT073 in mouse bladders and kidneys owing to the impaired ability of UPEC to form IBCs. Furthermore, we demonstrate that NDK inhibits caspase-1-dependent pyroptosis by consuming extracellular ATP, preventing superficial BEC exfoliation, and promoting IBC formation. UPEC utilizes the reactive oxygen species (ROS) sensor OxyR to indirectly activate the regulator integration host factor, which then directly activates ndk expression in response to intracellular ROS. Here, we reveal a signaling transduction pathway that UPEC employs to inhibit superficial BEC exfoliation, thus facilitating acute UTI.
Assuntos
Caspase 1 , Infecções por Escherichia coli , Núcleosídeo-Difosfato Quinase , Piroptose , Infecções Urinárias , Escherichia coli Uropatogênica , Escherichia coli Uropatogênica/patogenicidade , Animais , Infecções Urinárias/microbiologia , Infecções Urinárias/patologia , Camundongos , Caspase 1/metabolismo , Núcleosídeo-Difosfato Quinase/metabolismo , Núcleosídeo-Difosfato Quinase/genética , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/metabolismo , Infecções por Escherichia coli/patologia , Espécies Reativas de Oxigênio/metabolismo , Camundongos Endogâmicos C57BL , Humanos , Feminino , Bexiga Urinária/microbiologia , Bexiga Urinária/patologia , Células Epiteliais/microbiologia , Células Epiteliais/metabolismo , Proteínas de Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Transdução de SinaisRESUMO
Urinary tract infections are primarily caused by uropathogenic Escherichia coli (UPEC). UPEC infects bladder epithelial cells (BECs) via fusiform vesicles and escapes into the cytosol by disrupting fusiform vesicle membrane using outer membrane phospholipase PldA, and establishes biofilm-like intracellular bacterial communities (IBCs) for protection from host immune clearance. Cytosolic UPEC is captured by autophagy to form autophagosomes, then transported to lysosomes, triggering the spontaneous exocytosis of lysosomes. The mechanism by which UPEC evades autophagy to recognize and form IBCs remains unclear. Here, we demonstrate that by inhibiting autophagic flux, UPEC PldA reduces the lysosome exocytosis of BECs. By reducing intracellular phosphatidylinositol 3-phosphate levels, UPEC PldA increases the accumulation of NDP52 granules and decreases the targeting of NDP52 to autophagy, hence stalling preautophagosome structures. Thus, our results uncover a critical role for PldA to inhibit autophagic flux, favoring UPEC escapes from lysosome exocytosis, thereby contributing to acute urinary tract infection.
Assuntos
Autofagia , Células Epiteliais , Infecções por Escherichia coli , Exocitose , Lisossomos , Infecções Urinárias , Escherichia coli Uropatogênica , Escherichia coli Uropatogênica/fisiologia , Lisossomos/metabolismo , Lisossomos/microbiologia , Autofagia/fisiologia , Humanos , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/metabolismo , Células Epiteliais/microbiologia , Infecções Urinárias/microbiologia , Autofagossomos/metabolismo , Bexiga Urinária/microbiologia , Interações Hospedeiro-Patógeno , Proteínas de Escherichia coli/metabolismo , Proteínas de Escherichia coli/genéticaRESUMO
IMPORTANCE: The important enteropathogen Salmonella can cause lethal systemic infection via survival and replication in host macrophages. Lactate represents an abundant intracellular metabolite during bacterial infection, which can also induce macrophage M2 polarization. In this study, we found that macrophage-derived lactate promotes the intracellular replication and systemic infection of Salmonella. During Salmonella infection, lactate via the Salmonella type III secretion system effector SteE promotes macrophage M2 polarization, and the induction of macrophage M2 polarization by lactate is responsible for lactate-mediated Salmonella growth promotion. This study highlights the complex interactions between Salmonella and macrophages and provides an additional perspective on host-pathogen crosstalk at the metabolic interface.
Assuntos
Infecções Bacterianas , Infecções por Salmonella , Humanos , Ácido Láctico/metabolismo , Macrófagos/microbiologia , Infecções por Salmonella/metabolismo , Infecções Bacterianas/metabolismo , SalmonellaRESUMO
Two novel cinnamoyl-containing nonribosomal peptides (CCNPs) grisgenomycin A and B were identified in Streptomyces griseus NBRC 13350 (CGMCC 4.5718) and ATCC 12475, through genome mining using conserved adjacent LuxR family regulators as probes and activators. Notably, grisgenomycins represent a new group of bicyclic decapeptides featuring an unprecedented C-C bond between the tryptophan carbocycle and the cinnamoyl group. A plausible biosynthetic pathway for grisgenomycins was deduced by a bioinformatics analysis. Grisgenomycins exhibited activity against human coronaviruses at the micromolar level.
Assuntos
Streptomyces griseus , Streptomyces , Humanos , Streptomyces/genética , Streptomyces/metabolismo , Peptídeos/química , Genoma Bacteriano , Vias Biossintéticas/genética , Família MultigênicaRESUMO
Three Gram-stain-positive, aerobic, motile actinobacterial strains designated as CPCC 205119T, CPCC 205215, and CPCC 205251 were isolated from different biological soil crust samples collected from Tengger Desert, China. The 16S rRNA gene sequence comparison of these three strains showed they had almost identical 16S rRNA genes, which were closely related to members of the family Geodermatophilaceae, with the highest similarities of 96.3-97.3% to the species of Modestobacter. In the phylogenetic tree based on 16S rRNA gene sequences, these isolates clustered into a subclade next to the branch containing the species of Modestobacter lapidis and Modestobacter multiseptatus, within the lineage of the genus Modestobacter. The comparative genomic characteristics (values of ANI, dDDH, AAI, and POCP) and the phenotypic properties (morphological, physiological, and chemotaxonomic characteristics) of these isolates readily supported to affiliate them to the genus Modestobacter as a single separate species. For which, we proposed that the isolates CPCC 205119T, CPCC 205215, and CPCC 205251 represent a novel species of the genus Modestobacter as Modestobacter deserti sp. nov. CPCC 205119T (=I12A-02624=NBRC 113528T=KCTC 49201T) is the type strain. The genome of strain CPCC 205119T consisted of one chromosome (4,843,235bp) containing 4,424 coding genes, 48 tRNA genes, five rRNA genes, three other ncRNA genes, and 101 pseudogenes, with G+C content of 74.7%. The whole-genome sequences analysis indicated that this species contained alkaline phosphatase genes (phoA/phoD), phosphate transport-related genes (phoU, phnC, phnD, phnE, phoB, phoH, phoP, phoR, pitH, ppk, pstA, pstB, pstC, and pstS), trehalose-phosphate synthase gene (otsA), trehalose 6-phosphate phosphatase gene (otsB) and other encoding genes for the properties that help the microorganisms to adapt to harsh environmental conditions prevalent in deserts. Strains of this species could solubilize tricalcium phosphate [Ca3(PO4)2] and phytin, assimilate pyrophosphate, thiophosphate, dithiophosphate, phosphoenol pyruvate, 2-deoxy-d-glucose-6-phosphate, and cysteamine-S-phosphate.
RESUMO
OBJECTIVE: Coagulation factor V (FV) is distributed in plasma and platelet pools, which are distinguished by physical and functional differences. FV has been extensively studied for its roles in coagulation. The roles of FV in other physiologic pathways remain understudied. METHODS: Hind limb ischemia was produced in transgenic mice by femoral artery ligation, with different levels of FV gene expression restricted to the plasma or platelets. RESULTS: Hind limb blood flow perfusion in mice with higher platelet FV was significantly increased. The expression of major angiogenesis-related factors was correlated with the level of FV during ischemia. Furthermore, a platelet depletion and transfusion procedure showed that the transfusion of platelets with higher levels of FV into transgenic mice with undetectable platelet FV significantly rescued the ischemia-mediated impairments in blood flow perfusion. Immunohistochemistry analysis also indicated markedly increased capillary formation in the ischemic muscle of mice with higher platelet FV. Moreover, thrombin activity was significantly higher in the mice with higher platelet FV. Platelets expressing higher levels of FV stimulated increased endothelial cell migration. Hind limb blood flow perfusion was significantly blocked by thrombin inhibitor. CONCLUSIONS: These findings suggest that platelet-derived FV contributes to the control of angiogenesis and is likely associated with thrombin generation.
Assuntos
Plaquetas/metabolismo , Fator V/metabolismo , Isquemia/terapia , Músculo Esquelético/irrigação sanguínea , Neovascularização Fisiológica , Transfusão de Plaquetas , Proteínas Angiogênicas/genética , Proteínas Angiogênicas/metabolismo , Animais , Antitrombinas/farmacologia , Velocidade do Fluxo Sanguíneo , Movimento Celular , Células Cultivadas , Modelos Animais de Doenças , Células Endoteliais/metabolismo , Fator V/genética , Genótipo , Membro Posterior , Hirudinas/farmacologia , Isquemia/sangue , Isquemia/genética , Isquemia/fisiopatologia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Fenótipo , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Fluxo Sanguíneo Regional , Trombina/metabolismo , Fatores de TempoRESUMO
A novel endophytic actinobacterium, designated strain CPCC 204076T, was isolated from surface-sterilized tissue of the medicinal plant Huperzia serrata (Thunb.) collected from Sichuan Province, south-west China. The taxonomic position of the isolate was investigated by a polyphasic approach. The strainwas aerobic, Gram-stain-positive, non-motile, non-spore-forming and rod-shaped. Growth was observed at 10-37 °C, at pH 5.0-10.0 and with 0-3.0 % (w/v) NaCl. The polar lipid fraction consisted of diphosphatidylglycerol, a phospholipid, an aminolipid, a glycolipid, an aminophospholipid and phosphatidylinositol. The cell wall contained meso-diaminopimelic acid as the diagnostic diamino acid and the peptidoglycan was of type A4γ. The menaquinone system consisted of MK-9(H4) and MK-8(H4). The major cellular fatty acids (>10 %) were iso-C16 : 0 and anteiso-C17 : 0. The genomic DNA G+C content of strain CPCC 204076T was found to be 71.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that CPCC 204076T belongs to the genus Jatrophihabitans with highest sequence similarity to Jatrophihabitans endophyticus DSM 45627T (96.5 %), Jatrophihabitans soli DSM 45908T (96.5 %) and Jatrophihabitans fulvus JCM 30448T (96.1 %), and much lower similarities (<95.0 %) to other available 16S rRNA gene sequences from validly described pure cultures. However, DNA-DNA hybridyzation values between strain CPCC 204076T and the three recognized Jatrophihabitans species were 31±3.1 % (J. endophyticus DSM 45627T), 33±2.9 % (J. soli DSM 45908T) and 37±1.7 % (J. fulvus JCM 30448T), which were all far below the recommended cut-off value of 70 %. The phenotypic and genomic characteristics distinctly indicated that strain CPCC 204076T represents a novel species of the genus Jatrophihabitans, for which the name Jatrophihabitans huperziae sp. nov. is proposed. The type strain is CPCC 204076T (I13A-01604) (=DSM 46866T=NBRC 110718T).
Assuntos
Actinobacteria/classificação , Huperzia/microbiologia , Filogenia , Actinobacteria/genética , Actinobacteria/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , Parede Celular/química , China , DNA Bacteriano/genética , Ácido Diaminopimélico/química , Ácidos Graxos/química , Glicolipídeos/química , Hibridização de Ácido Nucleico , Peptidoglicano/química , Fosfolipídeos/química , Plantas Medicinais/microbiologia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMO
A novel aerobic actinomycete, designated strain I12A-02601T, was isolated from a desert soil crusts sample collected from the Shapotou region of Tengger Desert, north-west China. The substrate mycelia of this isolate were well-developed and branched, but not fragmented. The maturity aerial mycelia formed short chains of small, rod-shaped spores. The strain contained ll-diaminopimelic acid, dd-diaminopimelic acid, galactose, glucose, ribose and xylose in its whole-cell hydrolysates. The polar lipids consisted of diphosphatidylglycerol, N-acetylglucosamine-containing phospholipids, phosphatidylinositolmannoside and glycolipids. The predominant menaquinones were MK-10(H6) and MK-10(H8). The major fatty acids were iso-C15 : 0, anteiso-C15 : 0, C16 : 0, anteiso-C17 : 0 and iso-C16 : 0. The G+C content of the genomic DNA was 72.2âmol%. The 16S rRNA gene sequences comparison showed that strain I12A-02601T was most closely related to members of the family Nocardioidaceae, such as Actinopolymorpha alba YIM 48868T (93.3 % sequence similarity), Actinopolymorpha pittospori PIP 143T (93.2 %), and Flindersiella endophytica EUM 378T (93.2 %). In the phylogenetic tree based on 16S rRNA gene sequences, strain I12A-02601T formed a clade with the members of the genera Flindersiella, Thermasporomyces, and Actinopolymorpha in the family Nocardioidaceae. Combined data from this taxonomic study using a polyphasic approach, led to the conclusion that strain I12A-02601T represents a novel species of a new genus in the family Nocardioidaceae, for which the name Tenggerimyces mesophilus gen. nov., sp. nov. is proposed. The type strain of the type species is I12A-02601T ( = CPCC 203544T = DSM 45829T = NBRC 109454T).
Assuntos
Actinomycetales/classificação , Filogenia , Microbiologia do Solo , Actinomycetales/genética , Actinomycetales/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Clima Desértico , Ácido Diaminopimélico/química , Ácidos Graxos/química , Dados de Sequência Molecular , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/químicaRESUMO
An actinomycete strain, designated I12A-02593(T), was isolated from a desert soil crust sample collected in the Shapotou region of Tengger Desert, north-west China. The isolate grew well on International Streptomyces Project (ISP) media 2, 3, 5 and 7, YS and Bennett's agar; it produced spherical bodies and formed clumps on the aerial mycelia on ISP 5 agar plates. Chemotaxonomically, the strain contained meso-diaminopimelic acid as the diagnostic diamino acid, arabinose and galactose as the diagnostic sugars in whole-cell hydrolysates, MK-9(H4) as the sole isoprenoid quinone, and iso-C16â:â0, iso-C16â:â0 2-OH and iso-C16â:â1 H as the major cellular fatty acids, without mycolic acids. The profile of the phospholipids mainly comprised diphosphatidylglycerol, phosphatidylethanolamine and hydroxyphosphatidylethanolamine. The genomic DNA G+C content was 70.1 mol%. The 16S rRNA gene sequence of strain I12A-02593(T) exhibited 96.4-97.4â% similarities with members of the genus Actinophytocola. In the phylogenetic tree based on 16S rRNA gene sequences, the isolate formed a robust cluster with Actinophytocola oryzae NBRC 105245(T), Aactinophytocola timorensis NBRC 105524(T), Actinophytocola corallina NBRC 105525(T), Actinophytocola burenkhanensis NBRC 105883(T)and Actinophytocola xinjiangensis NBRC 106673(T). DNA-DNA hybridization values between strain I12A-02593(T) and the five species of the genus Actinophytocola were all less than 70â%. On the basis of the polyphasic taxonomy evidence, a novel species of the genus Actinophytocola is proposed, with the name Actinophytocola gilvus sp. nov. The type strain is I12A-02593(T) (â=âCPCC 203543(T)â=âDSM 45828(T)â=âNBRC 109453(T)â=âKCTC 29165(T)). An emended description of the genus Actinophytocola is also provided.
Assuntos
Actinomycetales/classificação , Filogenia , Microbiologia do Solo , Actinomycetales/genética , Actinomycetales/isolamento & purificação , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Clima Desértico , Ácido Diaminopimélico/química , Ácidos Graxos/química , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMO
The association between glutathione-S-transferase polymorphisms (GSTM1, GSTT1 and GSTP1) and risk of acute leukemia in Asians remains controversial. This study was therefore designed to evaluate the precise association in 23 studies identified by a search of PubMed and several other databases, up to December 2013. Using random or fixed effects models odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were calculated. Heterogeneity across studies was assessed, and funnel plots were constructed to test for publication bias. The meta-analysis showed positive associations between GST polymorphisms (GSTM1 and GSTT1 but not GSTP1) and acute leukemia risk [(OR=1.47, 95% CI 1.18-1.83); (OR=1.32, 95% CI 1.07-1.62); (OR=1.01, 95% CI 0.84-1.23), respectively] and heterogeneity between the studies. The results suggested that the GSTM1 null genotype and GSTT1null genotype, but not the GSTP1 polymorphism, might be a potential risk factors for acute leukemia. Further well-designed studies are needed to confirm our findings.
Assuntos
Povo Asiático/genética , Predisposição Genética para Doença/genética , Glutationa S-Transferase pi/genética , Glutationa Transferase/genética , Polimorfismo Genético/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Genótipo , Humanos , Lactente , Recém-Nascido , Pessoa de Meia-Idade , Risco , Fatores de Risco , Adulto JovemRESUMO
MicroRNA-183 (miR-183) family is proposed as promising biomarkers for early cancer detection and accurate prognosis as well as targets for more efficient treatment. The results of their expression feature in cancer tissues are inconsistent and controversy still exists in identifying them as new biomarkers of cancers. Therefore, to systemically evaluate the most frequently reported cancers in which miR-183 family members were up- or down-regulated is critical for further investigation on physiological impact of its aberrant regulation in specific cancers. The published studies that compared the level of miR-183 family expression in cancer tissues with those in noncancerous tissues were reviewed by the meta-analysis with a vote-counting strategy. Among the 49 included studies, a total of 18 cancers were reported, with 11 cancers reported in at least two studies. In the panel of miR-183 family members' expression analysis, colorectal cancer and prostate cancer ranked at the top among consistently reported cancer types with up-regulated feature. Bladder cancer, lung cancer and hepatocellular carcinoma were the third most frequently reported cancer types with significant over-expression of miR-96, miR-182 and miR-183 respectively. Breast cancer and gastric cancer were presented with inconsistent regulations and the members of this family had their own distinct regulated features in other different cancers. MiR-183 family, either individually or as a cluster, may be useful prognostic markers and/or therapeutic targets in several cancers. Further studies and repeat efforts are still required to determine the role of miR-183 family in various cancer progressions.
Assuntos
MicroRNAs/genética , Neoplasias/genética , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/metabolismo , Neoplasias/metabolismoAssuntos
Proteínas de Homeodomínio/metabolismo , Queratina-20/metabolismo , Queratina-7/metabolismo , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/secundário , Transativadores/metabolismo , Adenocarcinoma/metabolismo , Adenocarcinoma/secundário , Adulto , Idoso , Fator de Transcrição CDX2 , Carcinoma de Células em Anel de Sinete/metabolismo , Carcinoma de Células em Anel de Sinete/patologia , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Cistadenocarcinoma Mucinoso/metabolismo , Cistadenocarcinoma Mucinoso/patologia , Cistadenocarcinoma Seroso/metabolismo , Cistadenocarcinoma Seroso/patologia , Diagnóstico Diferencial , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Ovarianas/metabolismo , Adulto JovemRESUMO
The globally disseminated Streptococcus pyogenes M1T1 clone causes a number of highly invasive human diseases. The transition from local to systemic infection occurs by an unknown mechanism; however invasive M1T1 clinical isolates are known to express significantly less cysteine protease SpeB than M1T1 isolates from local infections. Here, we show that in comparison to the M1T1 strain 5448, the isogenic mutant delta speB accumulated 75-fold more human plasmin activity on the bacterial surface following incubation in human plasma. Human plasminogen was an absolute requirement for M1T1 strain 5448 virulence following subcutaneous (s.c.) infection of humanized plasminogen transgenic mice. S. pyogenes M1T1 isolates from the blood of infected humanized plasminogen transgenic mice expressed reduced levels of SpeB in comparison with the parental 5448 used as inoculum. We propose that the human plasminogen system plays a critical role in group A streptococcal M1T1 systemic disease initiation. SpeB is required for S. pyogenes M1T1 survival at the site of local infection, however, SpeB also disrupts the interaction of S. pyogenes M1T1 with the human plasminogen activation system. Loss of SpeB activity in a subpopulation of S. pyogenes M1T1 at the site of infection results in accumulation of surface plasmin activity thus triggering systemic spread.
Assuntos
Plasminogênio/fisiologia , Infecções Estreptocócicas/microbiologia , Streptococcus pyogenes/patogenicidade , Animais , Proteínas de Bactérias/genética , Exotoxinas/genética , Fibrinolisina/metabolismo , Regulação Bacteriana da Expressão Gênica , Humanos , Camundongos , Camundongos Transgênicos , Mutação , Infecções Estreptocócicas/etiologia , Streptococcus pyogenes/química , VirulênciaRESUMO
Pax genes are defined by the presence of a paired box that encodes a DNA-binding domain of 128 amino acids. They are involved in the development of the central nervous system, organogenesis, and oncogenesis. The known Pax genes are divided into five groups within two supergroups. By means of a novel combination of evolutionary analysis, in vitro binding assays and in vivo functional analyses, we have identified the key residues that determine the differing DNA-binding properties of the two supergroups and of the Pax-2, 5, 8 and Pax-6 subgroups within supergroup I. The differences in binding properties between the two supergroups are largely caused by amino acid changes at residues 20 and 121 of the paired domain. Although the paired domains of the Pax-2, 5, 8 and the Pax-6 group differ by >19 amino acids, their distinct DNA-binding properties are determined almost completely by a single amino acid change. Thus, a small number of amino acid changes can account in large part for the divergence in binding properties among the known paired domains. Our approach for selecting candidate sites responsible for the functional divergence between genes should also be useful for studying other gene families.