Pseudomonas aeruginosa is a significant pathogen mainly causing healthcare-associated infections(HAIs).Newly emerging high-risk clones of P.aeruginosa with elevated virulence profiles furtherly cause severe community-...Pseudomonas aeruginosa is a significant pathogen mainly causing healthcare-associated infections(HAIs).Newly emerging high-risk clones of P.aeruginosa with elevated virulence profiles furtherly cause severe community-acquired infections(CAIs).Usually,it is not common for P.aeruginosa to co-carry exoU and exoS genes,encoding two type III secretion system(T3SS)effectors.The pathogenicity mechanism of exoS+/exoU+strains of P.aeruginosa remains unclear.Here,we provide detailed evidence for a subset of hypervirulent P.aeruginosa strains,which abundantly co-express and secrete the T3SS effectors ExoS and ExoU.The exoS+/exoU+P.aeruginosa strains were available to cause both HAIs and CAIs.The CAI-associated strains could elicit severe inflammation and hemorrhage,leading to higher death rates in a murine acute pneumonia model,and had great virulence potential in establishing chronic infections,demonstrating hypervirulence when compared to PAO1(exoS+/exoU-)and PA14(exoS-/exoU+).Both ExoS and ExoU were co-expressed and co-secreted in abundance in exoS+/exoU+strains.Their abundant protein secretion could boost exoS+/exoU+strains’potentials for cytotoxicity in vitro and pathogenicity in vivo.Genomic evidence indicates that exoU acquisition is likely mediated by horizontal gene transfer(HGT)of the pathogenicity island PAPI-2,while deletion of exoU was sufficient to mitigate virulence in the exoS+/exoU+strains.Furthermore,bioinformatics analysis showed that such exoS+/exoU+P.aeruginosa strains turned out to be widely distributed across the globe.Overall,the research provide detailed evidence for the high virulence and epidemicity of exoS+/exoU+strains of P.aeruginosa,highlighting an urgent need for surveillance against these high-risk hypervirulent strains.展开更多
Objective:To use the gene chip of pseudomonas aeruginosa as a research sample and to explore it at an omics level,aiming at elucidating the co-expression network characteristics of the virulence genes exoS and exoU of...Objective:To use the gene chip of pseudomonas aeruginosa as a research sample and to explore it at an omics level,aiming at elucidating the co-expression network characteristics of the virulence genes exoS and exoU of pseudomonas aeruginosa in the lower respiratory tract from the perspective of molecular biology and identifying its key regulatory genes.Methods:From March 2016 to May 2018,312 patients infected with pseudomonas aeruginosa in the lower respiratory tract who were admitted to Department of Respiratory Medicine of Baogang Hospital and given follow-up treatments in the hospital were selected as subjects by use of cluster sampling.Alveolar lavage fluid and sputum collected from those patients were used as biological specimens.The genes of pseudomonas aeruginosa were detected with the help of oligonucleotide probes to make a pre-processing of chip data.A total of 8 common antibiotics(ceftazidime,gentamicin,piperacillin,amikacin,ciprofloxacin,levofloxacin,doripenem and ticarcillin)against Gram-negative bacteria were selected to determine the drug resistance of biological specimens.MCODE algorithm was used to construct a co-expression network model of the drug-resistance genes focused on exoS/exoU.Results:The expression level of exoS/exoU in the drug-resistance group was significantly higher than that in the non-resistance group(p<0.05).The top 5 differentially expressed genes in the alveolar lavage fluid specimens from the drug-resistance group were RAC1,ITGB1,ITGB5,CRK and IGF1R in the order from high to low.In the sputum specimens,the top 5 differentially expressed genes were RAC1,CRK,IGF1R,ITGB1 and ITGB5.In the alveolar lavage fluid specimens,only RAC1 had a positive correlation with the expression of exoS and exoU(p<0.05).In the sputum specimens,RAC1,ITGB1,ITGB5,CRK and IGF1R were positively correlated with the expression of exoS and exoU(p<0.05).The genes included in the co-expression network contained exoS,exoU,RAC1,ITGB1,ITGB5,CRK,CAMK2D,RHOA,FLNA,IGF1R,TGFBR2 and FOS.Among them,RAC1 had a highest 展开更多
There is growing evidence that long-term central nervous system(CNS)inflammation exacerbates secondary deterioration of brain structures and functions and is one of the major determinants of disease outcome and progre...There is growing evidence that long-term central nervous system(CNS)inflammation exacerbates secondary deterioration of brain structures and functions and is one of the major determinants of disease outcome and progression.In acute CNS injury,brain microglia are among the first cells to respond and play a critical role in neural repair and regeneration.However,microglial activation can also impede CNS repair and amplify tissue damage,and phenotypic transformation may be responsible for this dual role.Mesenchymal stem cell(MSC)-derived exosomes(Exos)are promising therapeutic agents for the treatment of acute CNS injuries due to their immunomodulatory and regenerative properties.MSC-Exos are nanoscale membrane vesicles that are actively released by cells and are used clinically as circulating biomarkers for disease diagnosis and prognosis.MSC-Exos can be neuroprotective in several acute CNS models,including for stroke and traumatic brain injury,showing great clinical potential.This review summarized the classification of acute CNS injury disorders and discussed the prominent role of microglial activation in acute CNS inflammation and the specific role of MSC-Exos in regulating pro-inflammatory microglia in neuroinflammatory repair following acute CNS injury.Finally,this review explored the potential mechanisms and factors associated with MSCExos in modulating the phenotypic balance of microglia,focusing on the interplay between CNS inflammation,the brain,and injury aspects,with an emphasis on potential strategies and therapeutic interventions for improving functional recovery from early CNS inflammation caused by acute CNS injury.展开更多
基金supported by grants from the National Key R&D Program of China(2021YFC2302005)the Joint Funds of the International Development Research Center of Canada(109282-001)the National Key R&D Program of China(2021YFC2301004 and 2017YFE0125600).
文摘Pseudomonas aeruginosa is a significant pathogen mainly causing healthcare-associated infections(HAIs).Newly emerging high-risk clones of P.aeruginosa with elevated virulence profiles furtherly cause severe community-acquired infections(CAIs).Usually,it is not common for P.aeruginosa to co-carry exoU and exoS genes,encoding two type III secretion system(T3SS)effectors.The pathogenicity mechanism of exoS+/exoU+strains of P.aeruginosa remains unclear.Here,we provide detailed evidence for a subset of hypervirulent P.aeruginosa strains,which abundantly co-express and secrete the T3SS effectors ExoS and ExoU.The exoS+/exoU+P.aeruginosa strains were available to cause both HAIs and CAIs.The CAI-associated strains could elicit severe inflammation and hemorrhage,leading to higher death rates in a murine acute pneumonia model,and had great virulence potential in establishing chronic infections,demonstrating hypervirulence when compared to PAO1(exoS+/exoU-)and PA14(exoS-/exoU+).Both ExoS and ExoU were co-expressed and co-secreted in abundance in exoS+/exoU+strains.Their abundant protein secretion could boost exoS+/exoU+strains’potentials for cytotoxicity in vitro and pathogenicity in vivo.Genomic evidence indicates that exoU acquisition is likely mediated by horizontal gene transfer(HGT)of the pathogenicity island PAPI-2,while deletion of exoU was sufficient to mitigate virulence in the exoS+/exoU+strains.Furthermore,bioinformatics analysis showed that such exoS+/exoU+P.aeruginosa strains turned out to be widely distributed across the globe.Overall,the research provide detailed evidence for the high virulence and epidemicity of exoS+/exoU+strains of P.aeruginosa,highlighting an urgent need for surveillance against these high-risk hypervirulent strains.
文摘Objective:To use the gene chip of pseudomonas aeruginosa as a research sample and to explore it at an omics level,aiming at elucidating the co-expression network characteristics of the virulence genes exoS and exoU of pseudomonas aeruginosa in the lower respiratory tract from the perspective of molecular biology and identifying its key regulatory genes.Methods:From March 2016 to May 2018,312 patients infected with pseudomonas aeruginosa in the lower respiratory tract who were admitted to Department of Respiratory Medicine of Baogang Hospital and given follow-up treatments in the hospital were selected as subjects by use of cluster sampling.Alveolar lavage fluid and sputum collected from those patients were used as biological specimens.The genes of pseudomonas aeruginosa were detected with the help of oligonucleotide probes to make a pre-processing of chip data.A total of 8 common antibiotics(ceftazidime,gentamicin,piperacillin,amikacin,ciprofloxacin,levofloxacin,doripenem and ticarcillin)against Gram-negative bacteria were selected to determine the drug resistance of biological specimens.MCODE algorithm was used to construct a co-expression network model of the drug-resistance genes focused on exoS/exoU.Results:The expression level of exoS/exoU in the drug-resistance group was significantly higher than that in the non-resistance group(p<0.05).The top 5 differentially expressed genes in the alveolar lavage fluid specimens from the drug-resistance group were RAC1,ITGB1,ITGB5,CRK and IGF1R in the order from high to low.In the sputum specimens,the top 5 differentially expressed genes were RAC1,CRK,IGF1R,ITGB1 and ITGB5.In the alveolar lavage fluid specimens,only RAC1 had a positive correlation with the expression of exoS and exoU(p<0.05).In the sputum specimens,RAC1,ITGB1,ITGB5,CRK and IGF1R were positively correlated with the expression of exoS and exoU(p<0.05).The genes included in the co-expression network contained exoS,exoU,RAC1,ITGB1,ITGB5,CRK,CAMK2D,RHOA,FLNA,IGF1R,TGFBR2 and FOS.Among them,RAC1 had a highest
文摘There is growing evidence that long-term central nervous system(CNS)inflammation exacerbates secondary deterioration of brain structures and functions and is one of the major determinants of disease outcome and progression.In acute CNS injury,brain microglia are among the first cells to respond and play a critical role in neural repair and regeneration.However,microglial activation can also impede CNS repair and amplify tissue damage,and phenotypic transformation may be responsible for this dual role.Mesenchymal stem cell(MSC)-derived exosomes(Exos)are promising therapeutic agents for the treatment of acute CNS injuries due to their immunomodulatory and regenerative properties.MSC-Exos are nanoscale membrane vesicles that are actively released by cells and are used clinically as circulating biomarkers for disease diagnosis and prognosis.MSC-Exos can be neuroprotective in several acute CNS models,including for stroke and traumatic brain injury,showing great clinical potential.This review summarized the classification of acute CNS injury disorders and discussed the prominent role of microglial activation in acute CNS inflammation and the specific role of MSC-Exos in regulating pro-inflammatory microglia in neuroinflammatory repair following acute CNS injury.Finally,this review explored the potential mechanisms and factors associated with MSCExos in modulating the phenotypic balance of microglia,focusing on the interplay between CNS inflammation,the brain,and injury aspects,with an emphasis on potential strategies and therapeutic interventions for improving functional recovery from early CNS inflammation caused by acute CNS injury.
