Background:Multimorbidity of intestinal cancer(IC),type 2 diabetes(T2D)and obesity is a complex set of diseases,affected by environmental and genetic risk factors.High-fat diet(HFD)and oral bacterial infection play im...Background:Multimorbidity of intestinal cancer(IC),type 2 diabetes(T2D)and obesity is a complex set of diseases,affected by environmental and genetic risk factors.High-fat diet(HFD)and oral bacterial infection play important roles in the etiology of these diseases through inflammation and various biological mechanisms.Methods:To study the complexity of this multimorbidity,we used the collaborative cross(CC)mouse genetics reference population.We aimed to study the multimorbidity of IC,T2D,and obesity using CC lines,measuring their responses to HFD and oral bacterial infection.The study used 63 mice of both sexes generated from two CC lines(IL557 and IL711).For 12 weeks,experimental mice were maintained on specific dietary regimes combined with co-infection with oral bacteria Porphyromonas gingivalis and Fusobacterium nucleatum,while control groups were not infected.Body weight(BW)and results of a intraperitoneal glucose tolerance test(IPGTT)were recorded at the end of 12 weeks,after which length and size of the intestines were assessed for polyp counts.Results:Polyp counts ranged between 2 and 10 per CC line.The combination of HFD and infection significantly reduced(P<.01)the colon polyp size of IL557 females to 2.5 cm 2,compared to the other groups.Comparing BW gain,IL557 males on HFD gained 18 g,while the females gained 10 g under the same conditions and showed the highest area under curve(AUC)values of 40000-45000(min mg/dL)in the IPGTT.Conclusion:The results show that mice from different genetic backgrounds respond differently to a high fat diet and oral infection in terms of polyp development and glucose tolerance,and this effect is gender related.展开更多
AB_(5)-type toxins are a group of secreted protein toxins that are central virulence factors for bacterial pathogens such as Shigella dysenteriae,Vibrio cholerae,Bordetella pertussis,and certain lineages of pathogenic...AB_(5)-type toxins are a group of secreted protein toxins that are central virulence factors for bacterial pathogens such as Shigella dysenteriae,Vibrio cholerae,Bordetella pertussis,and certain lineages of pathogenic Escherichia coli and Salmonella enterica.AB_(5) toxins are composed of an active(A)subunit that manipulates host cell biology in complex with a pentameric binding/delivery(B)subunit that mediates the toxin’s entry into host cells and its subsequent intracellular trafficking.Broadly speaking,all known AB_(5)-type toxins adopt similar structural architectures and employ similar mechanisms of binding,entering and trafficking within host cells.Despite this,there is a remarkable amount of diversity amongst AB_(5)-type toxins;this includes different toxin families with unrelated activities,as well as variation within families that can have profound functional consequences.In this review,we discuss the diversity that exists amongst characterized AB_(5)-type toxins,with an emphasis on the genetic and functional variability within AB_(5) toxin families,how this may have evolved,and its impact on human disease.展开更多
Cadmium(Cd)bioavailability in the rhizosphere makes an important difference in grain Cd accumulation in wheat.Here,pot experiments combined with 16S rRNA gene sequencing were conducted to compare the Cd bioavailabilit...Cadmium(Cd)bioavailability in the rhizosphere makes an important difference in grain Cd accumulation in wheat.Here,pot experiments combined with 16S rRNA gene sequencing were conducted to compare the Cd bioavailability and bacterial community in the rhizosphere of two wheat(Triticum aestivum L.)genotypes,a low-Cd-accumulating genotype in grains(LT)and a high-Cd-accumulating genotype in grains(HT),grown on four different soils with Cd contamination.Results showed that there was non-significant difference in total Cd concentration among four soils.However,except for black soil,DTPA-Cd concentrations in HT rhizospheres were higher than those of LT in fluvisol,paddy soil and purple soil.Results of 16S rRNA gene sequencing showed that soil type(52.7%)was the strongest determinant of root-associated community,while there were still some differences in rhizosphere bacterial community composition between twowheat genotypes.Taxa specifically colonized in HT rhizosphere(Acidobacteria,Gemmatimonadetes,Bacteroidetes and Deltaproteobacteria)could participate inmetal activation,whereas LT rhizosphere was highly enriched by plant growth-promoting taxa.In addition,PICRUSt2 analysis also predicted high relative abundances of imputed functional profiles related to membrane transport and amino acid metabolism in HT rhizosphere.These results revealed that the rhizosphere bacterial community may be an important factor regulating Cd uptake and accumulation in wheat and indicated that the high Cd-accumulating cultivar might improve Cd bioavailability in the rhizosphere by recruiting taxa related to Cd activation,thus promoting Cd uptake and accumulation.展开更多
To date,much of research on revegetation has focused on soil microorganisms due to their contributions in the formation of soil and soil remediation process.However,little is known about the soil bacteria and their fu...To date,much of research on revegetation has focused on soil microorganisms due to their contributions in the formation of soil and soil remediation process.However,little is known about the soil bacteria and their functions respond to the diverse vegetational types in the process of vegetation restoration.Effects of dominated vegetation,i.e.,Artemisia halodendron Turcz Ex Bess,Caragana microphylla Lam.,Hedysarum fruticosum Pall.and Pinus sylvestris L.on bacterial community structures and their potential functions in the Hulun Buir Sandy Land,China were determined using high-throughput 16S rRNA gene sequencing and phylogenetic investigation of communities by reconstruction of unobserved states(PICRUSt)in 2015.Although the dominant phyla of soil bacterial community among different types of vegetation,including Proteobacteria,Actinobacteria,Acidobacteria,Bacteroidetes and Firmicutes,were similar,the relative abundance of these dominant groups significantly differed,indicating that different types of vegetation might result in variations in the composition of soil bacterial community.In addition,functional genes of bacterial populations were similar among different types of vegetation,whereas its relative abundance was significantly differed.Most carbon fixation genes showed a high relative abundance in P.sylvestris,vs.recalcitrant carbon decomposition genes in A.halodendron,suggesting the variations in carbon cycling potential of different types of vegetation.Abundance of assimilatory nitrate reduction genes was the highest in P.sylvestris,vs.dissimilatory nitrate reduction and nitrate reductase genes in A.halodendron,indicating higher nitrogen gasification loss and lower nitrogen utilization gene functions in A.halodendron.The structures and functional genes of soil bacterial community showed marked sensitivities to different plant species,presenting the potentials for regulating soil carbon and nitrogen cycling.展开更多
Human disturbances to soils can lead to dramatic changes in soil physical,chemical,and biological properties.The influence of agricultural activities on the bacterial community over different orders of soil and at dep...Human disturbances to soils can lead to dramatic changes in soil physical,chemical,and biological properties.The influence of agricultural activities on the bacterial community over different orders of soil and at depth is still not well understood.We used the concept of genoform and phenoform to investigate the vertical(down to 1 m depth)soil bacterial community structure in paired genosoils(undisturbed forests)and phenosoils(cultivated vineyards)in different soil orders.The study was conducted in the Hunter Valley area,New South Wales,Australia,where samples were collected from 3 different soil orders(Calcarosol,Chromosol,and Kurosol),and each soil order consists of a pair of genosoil and phenosoil.The bacterial community structure was analyzed using highthroughput sequencing of 16S rRNA.Results showed that bacterial-diversity decreased with depth in phenosoils,however,the trend is less obvious in genoform profiles.Topsoil diversity was greater in phenosoils than genosoils,but the trend was reversed in subsoils.Thus,cropping not only affected topsoil bacteria community but also decreased its diversity in the subsoil.Bacterial community in topsoils was influenced by both soil orders and soil forms,however,in subsoils it was more impacted by soil orders.Constrained Analysis of Principal Coordinates revealed that cropping increased the similarity of bacterial structures of different soil orders.This study highlighted the strong influence of agricultural activities on soil microbial distribution with depth,which is controlled by soil order.展开更多
文摘Background:Multimorbidity of intestinal cancer(IC),type 2 diabetes(T2D)and obesity is a complex set of diseases,affected by environmental and genetic risk factors.High-fat diet(HFD)and oral bacterial infection play important roles in the etiology of these diseases through inflammation and various biological mechanisms.Methods:To study the complexity of this multimorbidity,we used the collaborative cross(CC)mouse genetics reference population.We aimed to study the multimorbidity of IC,T2D,and obesity using CC lines,measuring their responses to HFD and oral bacterial infection.The study used 63 mice of both sexes generated from two CC lines(IL557 and IL711).For 12 weeks,experimental mice were maintained on specific dietary regimes combined with co-infection with oral bacteria Porphyromonas gingivalis and Fusobacterium nucleatum,while control groups were not infected.Body weight(BW)and results of a intraperitoneal glucose tolerance test(IPGTT)were recorded at the end of 12 weeks,after which length and size of the intestines were assessed for polyp counts.Results:Polyp counts ranged between 2 and 10 per CC line.The combination of HFD and infection significantly reduced(P<.01)the colon polyp size of IL557 females to 2.5 cm 2,compared to the other groups.Comparing BW gain,IL557 males on HFD gained 18 g,while the females gained 10 g under the same conditions and showed the highest area under curve(AUC)values of 40000-45000(min mg/dL)in the IPGTT.Conclusion:The results show that mice from different genetic backgrounds respond differently to a high fat diet and oral infection in terms of polyp development and glucose tolerance,and this effect is gender related.
基金supported by a start-up grant provided by the Uni-versity of Alberta Faculty of Science(to C.C.F.)a Natural Sciences and Engineering Research Council of Canada(NSERC)Discovery Grant(Grant number:RGPIN-2020-03964 to C.C.F.).
文摘AB_(5)-type toxins are a group of secreted protein toxins that are central virulence factors for bacterial pathogens such as Shigella dysenteriae,Vibrio cholerae,Bordetella pertussis,and certain lineages of pathogenic Escherichia coli and Salmonella enterica.AB_(5) toxins are composed of an active(A)subunit that manipulates host cell biology in complex with a pentameric binding/delivery(B)subunit that mediates the toxin’s entry into host cells and its subsequent intracellular trafficking.Broadly speaking,all known AB_(5)-type toxins adopt similar structural architectures and employ similar mechanisms of binding,entering and trafficking within host cells.Despite this,there is a remarkable amount of diversity amongst AB_(5)-type toxins;this includes different toxin families with unrelated activities,as well as variation within families that can have profound functional consequences.In this review,we discuss the diversity that exists amongst characterized AB_(5)-type toxins,with an emphasis on the genetic and functional variability within AB_(5) toxin families,how this may have evolved,and its impact on human disease.
基金This research was financially supported by the National Natural Science Foundation of China(No.41721001-1)the General Programof National Natural Science Foundation of China(No.31872956)+1 种基金the Ministry of Ecology and Environmental Protection demonstration project(Nos.WA2020001 and WA202138)the Fundamental Research Funds for Central Universities.
文摘Cadmium(Cd)bioavailability in the rhizosphere makes an important difference in grain Cd accumulation in wheat.Here,pot experiments combined with 16S rRNA gene sequencing were conducted to compare the Cd bioavailability and bacterial community in the rhizosphere of two wheat(Triticum aestivum L.)genotypes,a low-Cd-accumulating genotype in grains(LT)and a high-Cd-accumulating genotype in grains(HT),grown on four different soils with Cd contamination.Results showed that there was non-significant difference in total Cd concentration among four soils.However,except for black soil,DTPA-Cd concentrations in HT rhizospheres were higher than those of LT in fluvisol,paddy soil and purple soil.Results of 16S rRNA gene sequencing showed that soil type(52.7%)was the strongest determinant of root-associated community,while there were still some differences in rhizosphere bacterial community composition between twowheat genotypes.Taxa specifically colonized in HT rhizosphere(Acidobacteria,Gemmatimonadetes,Bacteroidetes and Deltaproteobacteria)could participate inmetal activation,whereas LT rhizosphere was highly enriched by plant growth-promoting taxa.In addition,PICRUSt2 analysis also predicted high relative abundances of imputed functional profiles related to membrane transport and amino acid metabolism in HT rhizosphere.These results revealed that the rhizosphere bacterial community may be an important factor regulating Cd uptake and accumulation in wheat and indicated that the high Cd-accumulating cultivar might improve Cd bioavailability in the rhizosphere by recruiting taxa related to Cd activation,thus promoting Cd uptake and accumulation.
基金supported by the National Key Research and Development Program of China (2016YFC0500905)the National Natural Science Foundation of China (31600584)the Fundamental Research Funds for the Central Universities (2015ZCQSB-02)
文摘To date,much of research on revegetation has focused on soil microorganisms due to their contributions in the formation of soil and soil remediation process.However,little is known about the soil bacteria and their functions respond to the diverse vegetational types in the process of vegetation restoration.Effects of dominated vegetation,i.e.,Artemisia halodendron Turcz Ex Bess,Caragana microphylla Lam.,Hedysarum fruticosum Pall.and Pinus sylvestris L.on bacterial community structures and their potential functions in the Hulun Buir Sandy Land,China were determined using high-throughput 16S rRNA gene sequencing and phylogenetic investigation of communities by reconstruction of unobserved states(PICRUSt)in 2015.Although the dominant phyla of soil bacterial community among different types of vegetation,including Proteobacteria,Actinobacteria,Acidobacteria,Bacteroidetes and Firmicutes,were similar,the relative abundance of these dominant groups significantly differed,indicating that different types of vegetation might result in variations in the composition of soil bacterial community.In addition,functional genes of bacterial populations were similar among different types of vegetation,whereas its relative abundance was significantly differed.Most carbon fixation genes showed a high relative abundance in P.sylvestris,vs.recalcitrant carbon decomposition genes in A.halodendron,suggesting the variations in carbon cycling potential of different types of vegetation.Abundance of assimilatory nitrate reduction genes was the highest in P.sylvestris,vs.dissimilatory nitrate reduction and nitrate reductase genes in A.halodendron,indicating higher nitrogen gasification loss and lower nitrogen utilization gene functions in A.halodendron.The structures and functional genes of soil bacterial community showed marked sensitivities to different plant species,presenting the potentials for regulating soil carbon and nitrogen cycling.
基金This work was supported by the ARC Discovery project DP190103005 Synergising pedodiversity and soil biodiversity to secure soil functionality。
文摘Human disturbances to soils can lead to dramatic changes in soil physical,chemical,and biological properties.The influence of agricultural activities on the bacterial community over different orders of soil and at depth is still not well understood.We used the concept of genoform and phenoform to investigate the vertical(down to 1 m depth)soil bacterial community structure in paired genosoils(undisturbed forests)and phenosoils(cultivated vineyards)in different soil orders.The study was conducted in the Hunter Valley area,New South Wales,Australia,where samples were collected from 3 different soil orders(Calcarosol,Chromosol,and Kurosol),and each soil order consists of a pair of genosoil and phenosoil.The bacterial community structure was analyzed using highthroughput sequencing of 16S rRNA.Results showed that bacterial-diversity decreased with depth in phenosoils,however,the trend is less obvious in genoform profiles.Topsoil diversity was greater in phenosoils than genosoils,but the trend was reversed in subsoils.Thus,cropping not only affected topsoil bacteria community but also decreased its diversity in the subsoil.Bacterial community in topsoils was influenced by both soil orders and soil forms,however,in subsoils it was more impacted by soil orders.Constrained Analysis of Principal Coordinates revealed that cropping increased the similarity of bacterial structures of different soil orders.This study highlighted the strong influence of agricultural activities on soil microbial distribution with depth,which is controlled by soil order.
