Bacteroides fragilis (B.fragilis),a crucial commensal bacterium within the gut,has shown connections with hepatic lipid metabolism and inflammation regulation.Nonetheless,the role of B.fragilis in the progression of f...Bacteroides fragilis (B.fragilis),a crucial commensal bacterium within the gut,has shown connections with hepatic lipid metabolism and inflammation regulation.Nonetheless,the role of B.fragilis in the progression of fatty liver hemorrhagic syndrome (FLHS) remains unknown.This study aims to explore the ameliorative effects of B.fragilis on FLHS in laying hens,as well as its underlying mechanisms.This is the first study to employ a chicken FLHS model,combining microbiomics and oxylipin metabolomics to investigate the mechanism of action of intestinal symbiotic bacteria.Exp.1:40 laying hens at 25 weeks old were randomly divided into five treatment groups (eight replicates per group and one hen per replicate),including the control group (basal diet),the high-energy and low-protein (HELP) group,and the HELP group with three different levels (10~8,10~9,and 1010CFU) of B.fragilis.Exp.2:18 chickens at 25weeks old were randomly divided into three treatment groups (six replicates per group and one hen per replicate) including the control group (basal diet),the model group (HELP diet),and the arachidonic acid(AA) group (HELP diet with 0.3%AA).The experiment period of Exp.1 and Exp.2 were 8 weeks.B.fragilis significantly improved body weight of seventh week (P=0.006),liver lipid degeneration,blood lipid levels (triglycerides,cholesterol,and low-density lipoprotein cholesterol;P<0.05),and liver function(alanine aminotransferase and aminotransferase;P<0.05) in laying hens.B.fragilis downregulated the expression of lipid synthesis-related genes fatty acid synthase,acetyl-CoA carboxylase,and liver X receptor a,and inflammation-related genes tumor necrosis factor a,interleukin (IL)-1β,IL-6,and IL-8 in the liver of FLHS-affected hens (P<0.05),while upregulating the expression of lipid oxidation-related genes carnitine palmitoyl transferase-1,peroxisome proliferator activated receptor (PPAR) a,and PPARγ(P<0.05).The in-depth analysis indicated alterations in oxylipin pathways triggered by B.fragilis,as evidenced by changes in the expression of pivotal genes arachidonate 15-lipoxygenase,arachidonate 5-lipoxygenase (P<0.05),subsequently causing modifications in relevant metabolites.This included a decrease in pro-inflammatory substances such as 15-oxoETE (P=0.004),accompanied by an increase in AA (P=0.008).B.fragilis regulated the homeostasis of intestinal flora by increasing the abundance of Bacteroides and decreasing the abundance of Succinatimonas and Faecalicoccus (P<0.05).The integrated analysis revealed a robust positive correlation between Bacteroides abundance and AA levels (P=0.007).This relationship was corroborated through in vitro experiments.Subsequently,the beneficial effect of AA in mitigating FLHS was confirmed in laying hens with FLHS,further supported by reverse transcription-polymerase chain reaction analysis demonstrating gene expression patterns akin to B.fragilis intervention.This study demonstrated that B.fragilis exerts an anti-FLHS effect through modulation of oxylipin metabolism and gut microbiota stability,with a pivotal role played by AA.展开更多
On-tissue chemical derivatization(OTCD)effectively enhances ionization efficiency of low abundant and poorly ionized functional molecules to improve detection sensitivity and coverage of mass spectrometry imaging(MSI)...On-tissue chemical derivatization(OTCD)effectively enhances ionization efficiency of low abundant and poorly ionized functional molecules to improve detection sensitivity and coverage of mass spectrometry imaging(MSI).Combination OTCD and MSI provides a novel strategy for visualizing previously undisclosed metabolic heterogeneity in tumor.Herein,we present a method to visualize heterogeneous metabolism of oxylipins within tumor by coupling OTCD with airflow-assisted desorption electrospray ionization(AFADESI)-MSI.Taking Girard’s P as a derivatization reagent,easily ionized hydrazide and quaternary amine groups were introduced into the structure of carbonyl metabolites via condensation reaction.Oxylipins,including 127 fatty aldehydes(FALs)and 71 oxo fatty acids(FAs),were detected and imaged in esophageal cancer xenograft with AFADESI-MSI after OTCD.Then t-distributed stochastic neighbor embedding and random forest were exploited to precisely locate the distribution of oxylipins in heterogeneous tumor tissue.With this method,we surprisingly found almost all FALs and oxo FAs significantly accumulated in the core region of tumor,and exhibited a gradual increase trend in tumor over time.These results reveal spatiotemporal heterogeneity of oxylipins in tumor progression,highlighting the value of OTCD combined with MSI to gain deeper insights into understanding tumor metabolism.展开更多
Pyroptosis typically features the perforation of cell membranes,a process triggered by the exposure of active N-terminal domain of Gasdermin D(GSDMD).This pivotal event subsequently leads to the release of pro-inflamm...Pyroptosis typically features the perforation of cell membranes,a process triggered by the exposure of active N-terminal domain of Gasdermin D(GSDMD).This pivotal event subsequently leads to the release of pro-inflammatory cytokines,notably IL-1a and IL-1b,thereby fostering tissue inflammation and impeding the repair process 1.Moreover,the question of whether small molecule metabolites expelled through these pyroptotic pores possess specific physiological functions has consistently captivated the scientific community’s curiosity.A recent study published in Nature by Mehrotra et al.2 unveiled a novel paradigm,suggesting that oxygenated polyunsaturated fatty acids(oxylipins),released from pyroptotic cells,can paradoxically promote wound healing.This research demonstrates,as the famous saying goes,“From death comes rebirth”,innovatively revealing the interdependent relationship between cell death,inflammation,and repair.展开更多
Purpose:This study aimed to examine the linkage between gut microbiome taxa and exercise-induced inflammation.Methods:Twenty-five cyclists provided 4 stool samples during a 10-week period and cycled vigorously for 2.25...Purpose:This study aimed to examine the linkage between gut microbiome taxa and exercise-induced inflammation.Methods:Twenty-five cyclists provided 4 stool samples during a 10-week period and cycled vigorously for 2.25 h at 67%maximal oxygen uptake(VO2max)in a laboratory setting.Blood samples were collected pre-and post-exercise,with additional samples collected at 1.5-h,3-h,and 24-h post exercise.Primary outcomes included stool microbiome composition and alpha diversity via whole genome shotgun(WGS)sequencing(averaged from 4 stool samples)and a targeted panel of 75 plasma oxylipins.A total of 5719 taxa were identified,and the 339 that were present in more than 20%of stool samples were used in the analysis.Alpha diversity was calculated by evenness,and the Analysis of Composition of Microbiomes(ANCOM)differential abundance analysis was performed using Quantitative Insights Into Microbial Ecology-2(QIIME2).A composite variable was calculated from 8 pro-inflammatory oxylipins generated from arachidonic acid(ARA)and cytochrome P-450(CYP).Results:ARA-CYP oxylipins were significantly elevated for at least 3-h post-exercise(p<0.001);they were strongly and positively related to Prevotella copri(P.copri)abundance(R2=0.676,p<0.001)and negatively related to gut microbiome alpha diversity(R2=0.771,p<0.001).Conclusion:This analysis revealed for thefirst time a novel,positive relationship between gut microbiome P.copri abundance in cyclists and post-exercise pro-inflammatory oxylipins.These data demonstrate that about two-thirds of the wide variance in inflammation following prolonged and intensive exercise is largely explained by the abundance of a single gut bacterial species:P.copri.展开更多
Plants have evolved complex signaling pathways to coordinate responses to developmental and environmental Information. The oxylipin pathway Is one pivotal lipid-based signaling network, composed of several competing b...Plants have evolved complex signaling pathways to coordinate responses to developmental and environmental Information. The oxylipin pathway Is one pivotal lipid-based signaling network, composed of several competing branch pathways, that determines the plant＇s ability to adapt to various stimuli. Activation of the oxyllpln pathway Induces the de novo synthesis of biologically active metabolltes called ＂oxyllplns＂. The relative levels of these metabolltes are a distinct indicator of each plant species and determine the ability of plants to adapt to different stimuli. The two major branches of the oxyllpln pathway, allene oxide synthase （AOS） and hydroperoxlde lyase （HPL） are responsible for production of the signaling compounds, jasmonates and aldehydes respectively. Here, we compare and contrast the regulation of AOS and HPL branch pathways In rice and Arabidopsis as model monocotyledonous and dicotyledonous systems. These analyses provide new Insights Into the evolution of JAs and aldehydes signaling pathways, and the complex network of processes responsible for stress adaptations In monocots and dicots.展开更多
Plant 9-1ipoxygenases （9-LOX） and α-dioxygenases （α-DOX） initiate the synthesis of oxylipins after bacterial infection. Here, the role of these enzymes in plants＇ defense was investigated using individual Arabi...Plant 9-1ipoxygenases （9-LOX） and α-dioxygenases （α-DOX） initiate the synthesis of oxylipins after bacterial infection. Here, the role of these enzymes in plants＇ defense was investigated using individual Arabidopsis thaliana Ioxl and doxl mutants and a double Ioxl doxl mutant. Studies with Pseudomonas syringae pv. tomato （Pst） revealed the enhanced susceptibility of Ioxl to the virulent strain Pst DC3000 and the partial impairment of Ioxl and doxl mutants to activate systemic acquired resistance. Notably, both defects were enhanced in the Ioxl doxl plants as compared with individual mutants. We found that pre-treatment with 9-LOX- and α-DOX-generated oxylipins protected plant tissues against bacterial infection. The strongest effect in this respect was exerted by 9-ketooctadecatrienoic acid （9-KOT）, which is produced from linolenic acid by 9-LOX. Quantification of 9-KOT revealed its accumulation after bacterial infection. The levels were reduced in Ioxl and Ioxl doxl plants but strongly increased in the doxl mutant due to metabolic interaction of the two pathways. Transcriptional analyses indicated that 9-KOT pre-treatment modifies hormone homeostasis during bacterial infection. The nature of the changes detected suggested that 9-KOT interferes with the hormonal changes caused by bacterial effectors. This notion was substantiated by the finding that 9-KOT failed to reduce the growth of PstDC3OOOhrpA, a mutant compromised in effector secretion, and of the avirulent strain Pst DC3000 avrRpml. Further support for the action of the 9-LOX- and α-DOX-oxylipin pathways as modulators of hormone homeostasis was the ob- servation that Ioxl doxl seedlings are hypersensitive to the growth-inhibitory effect of ABA and showed enhanced ac- tivation of ABA-inducible marker genes as compared with wild-type plants.展开更多
To gain an understanding of the molecular ba-sis of signaling pathways in herbivore-induced maize plant defense, three key genes, ZmAOS, ZmAOC and ZmHPL, which are involved in the biosynthesis of oxylipin signals, hav...To gain an understanding of the molecular ba-sis of signaling pathways in herbivore-induced maize plant defense, three key genes, ZmAOS, ZmAOC and ZmHPL, which are involved in the biosynthesis of oxylipin signals, have been cloned using RT-PCR in this study. Beet army-worm (BAW) infestation induced the systemic expression of the key genes involved in the biosynthesis of oxylipin signals similar to exogenous methyl jasmonate (MeJA). Moreover, the systemic expression patterns of maize defense-related genes were similar between maize leaves induced by jas-monic acid (JA) and damaged by BAW. Previous treatment with salicyhydroxamic acid (SHAM), an inhibitor of jas-monates (JAs) signal pathway followed by BAW infestation did not induce the systemic expression of the defense-related genes. Exposure to the vapors of green leafy volatiles (GLVs, (Z)-3-hexen-1-ol, (E)-2-hexenal, (E)-3-hexenal) and β-oci- mene induced the expression of the defense-related genes, as well as the key genes involved in biosynthesis of JAs. How-ever, previous treatment with SHAM clearly decreased the transcript levels of the defense genes induced by (Z)-3-hexen-1-ol, (E)-2-hexenal and (E)-3- hexenal. These results demonstrate the major role of oxylipin signal path-way in herbivore-induced maize chemical defense. JA was the endogenous signal in the process of herbivore-induced maize systemic defense. GLVs, another group of oxylipin, played an important role in the process of herbivore-induced systemic defense outside the plant. Furthermore, the expres-sion of defense-related genes induced by GLVs was partially dependent on JAs signal pathway, while β-ocimene induction was independent of JAs signal pathway.展开更多
基金supported by the Natural Science Foundation of Hebei Province(C2021204035)Key Research and Development Projects of Hebei Province(22326619D)。
文摘Bacteroides fragilis (B.fragilis),a crucial commensal bacterium within the gut,has shown connections with hepatic lipid metabolism and inflammation regulation.Nonetheless,the role of B.fragilis in the progression of fatty liver hemorrhagic syndrome (FLHS) remains unknown.This study aims to explore the ameliorative effects of B.fragilis on FLHS in laying hens,as well as its underlying mechanisms.This is the first study to employ a chicken FLHS model,combining microbiomics and oxylipin metabolomics to investigate the mechanism of action of intestinal symbiotic bacteria.Exp.1:40 laying hens at 25 weeks old were randomly divided into five treatment groups (eight replicates per group and one hen per replicate),including the control group (basal diet),the high-energy and low-protein (HELP) group,and the HELP group with three different levels (10~8,10~9,and 1010CFU) of B.fragilis.Exp.2:18 chickens at 25weeks old were randomly divided into three treatment groups (six replicates per group and one hen per replicate) including the control group (basal diet),the model group (HELP diet),and the arachidonic acid(AA) group (HELP diet with 0.3%AA).The experiment period of Exp.1 and Exp.2 were 8 weeks.B.fragilis significantly improved body weight of seventh week (P=0.006),liver lipid degeneration,blood lipid levels (triglycerides,cholesterol,and low-density lipoprotein cholesterol;P<0.05),and liver function(alanine aminotransferase and aminotransferase;P<0.05) in laying hens.B.fragilis downregulated the expression of lipid synthesis-related genes fatty acid synthase,acetyl-CoA carboxylase,and liver X receptor a,and inflammation-related genes tumor necrosis factor a,interleukin (IL)-1β,IL-6,and IL-8 in the liver of FLHS-affected hens (P<0.05),while upregulating the expression of lipid oxidation-related genes carnitine palmitoyl transferase-1,peroxisome proliferator activated receptor (PPAR) a,and PPARγ(P<0.05).The in-depth analysis indicated alterations in oxylipin pathways triggered by B.fragilis,as evidenced by changes in the expression of pivotal genes arachidonate 15-lipoxygenase,arachidonate 5-lipoxygenase (P<0.05),subsequently causing modifications in relevant metabolites.This included a decrease in pro-inflammatory substances such as 15-oxoETE (P=0.004),accompanied by an increase in AA (P=0.008).B.fragilis regulated the homeostasis of intestinal flora by increasing the abundance of Bacteroides and decreasing the abundance of Succinatimonas and Faecalicoccus (P<0.05).The integrated analysis revealed a robust positive correlation between Bacteroides abundance and AA levels (P=0.007).This relationship was corroborated through in vitro experiments.Subsequently,the beneficial effect of AA in mitigating FLHS was confirmed in laying hens with FLHS,further supported by reverse transcription-polymerase chain reaction analysis demonstrating gene expression patterns akin to B.fragilis intervention.This study demonstrated that B.fragilis exerts an anti-FLHS effect through modulation of oxylipin metabolism and gut microbiota stability,with a pivotal role played by AA.
基金supported by the National Natural Science Foundation of China(No.21927808)the Chinese Academy of Medical Science(CAMS)Innovation Fund for Medical Sciences(CIFMS,Nos.2022-I2M-2-002 and 2021-1-I2M-028).
文摘On-tissue chemical derivatization(OTCD)effectively enhances ionization efficiency of low abundant and poorly ionized functional molecules to improve detection sensitivity and coverage of mass spectrometry imaging(MSI).Combination OTCD and MSI provides a novel strategy for visualizing previously undisclosed metabolic heterogeneity in tumor.Herein,we present a method to visualize heterogeneous metabolism of oxylipins within tumor by coupling OTCD with airflow-assisted desorption electrospray ionization(AFADESI)-MSI.Taking Girard’s P as a derivatization reagent,easily ionized hydrazide and quaternary amine groups were introduced into the structure of carbonyl metabolites via condensation reaction.Oxylipins,including 127 fatty aldehydes(FALs)and 71 oxo fatty acids(FAs),were detected and imaged in esophageal cancer xenograft with AFADESI-MSI after OTCD.Then t-distributed stochastic neighbor embedding and random forest were exploited to precisely locate the distribution of oxylipins in heterogeneous tumor tissue.With this method,we surprisingly found almost all FALs and oxo FAs significantly accumulated in the core region of tumor,and exhibited a gradual increase trend in tumor over time.These results reveal spatiotemporal heterogeneity of oxylipins in tumor progression,highlighting the value of OTCD combined with MSI to gain deeper insights into understanding tumor metabolism.
基金supported,in part,by Natural Science Foundation of China(T2341004,82321004,82374558,82074511,81973660)the National Key Research and Development Program of China(2022YFE0206200 and 2023YFC2414500)+1 种基金Guangdong Basic and Applied Basic Research Foundation(2021B1515120023,China)Guangzhou Basic and Applied Basic Research Foundation(2024A04J4020,China).
文摘Pyroptosis typically features the perforation of cell membranes,a process triggered by the exposure of active N-terminal domain of Gasdermin D(GSDMD).This pivotal event subsequently leads to the release of pro-inflammatory cytokines,notably IL-1a and IL-1b,thereby fostering tissue inflammation and impeding the repair process 1.Moreover,the question of whether small molecule metabolites expelled through these pyroptotic pores possess specific physiological functions has consistently captivated the scientific community’s curiosity.A recent study published in Nature by Mehrotra et al.2 unveiled a novel paradigm,suggesting that oxygenated polyunsaturated fatty acids(oxylipins),released from pyroptotic cells,can paradoxically promote wound healing.This research demonstrates,as the famous saying goes,“From death comes rebirth”,innovatively revealing the interdependent relationship between cell death,inflammation,and repair.
基金supported by Ocean Spray (https://www. oceanspray.com/)
文摘Purpose:This study aimed to examine the linkage between gut microbiome taxa and exercise-induced inflammation.Methods:Twenty-five cyclists provided 4 stool samples during a 10-week period and cycled vigorously for 2.25 h at 67%maximal oxygen uptake(VO2max)in a laboratory setting.Blood samples were collected pre-and post-exercise,with additional samples collected at 1.5-h,3-h,and 24-h post exercise.Primary outcomes included stool microbiome composition and alpha diversity via whole genome shotgun(WGS)sequencing(averaged from 4 stool samples)and a targeted panel of 75 plasma oxylipins.A total of 5719 taxa were identified,and the 339 that were present in more than 20%of stool samples were used in the analysis.Alpha diversity was calculated by evenness,and the Analysis of Composition of Microbiomes(ANCOM)differential abundance analysis was performed using Quantitative Insights Into Microbial Ecology-2(QIIME2).A composite variable was calculated from 8 pro-inflammatory oxylipins generated from arachidonic acid(ARA)and cytochrome P-450(CYP).Results:ARA-CYP oxylipins were significantly elevated for at least 3-h post-exercise(p<0.001);they were strongly and positively related to Prevotella copri(P.copri)abundance(R2=0.676,p<0.001)and negatively related to gut microbiome alpha diversity(R2=0.771,p<0.001).Conclusion:This analysis revealed for thefirst time a novel,positive relationship between gut microbiome P.copri abundance in cyclists and post-exercise pro-inflammatory oxylipins.These data demonstrate that about two-thirds of the wide variance in inflammation following prolonged and intensive exercise is largely explained by the abundance of a single gut bacterial species:P.copri.
基金Supported by UC discovery and NSF grants to KD. Publication of this paper is supported by the National Natural Science Foundation of China （30624808） and Science Publication Foundation of the Chinese Academy of Sciences.Acknowledgements The authors would like to acknowledge G. Raman for performing the jasmonate and aldehyde measurements.
文摘Plants have evolved complex signaling pathways to coordinate responses to developmental and environmental Information. The oxylipin pathway Is one pivotal lipid-based signaling network, composed of several competing branch pathways, that determines the plant＇s ability to adapt to various stimuli. Activation of the oxyllpln pathway Induces the de novo synthesis of biologically active metabolltes called ＂oxyllplns＂. The relative levels of these metabolltes are a distinct indicator of each plant species and determine the ability of plants to adapt to different stimuli. The two major branches of the oxyllpln pathway, allene oxide synthase （AOS） and hydroperoxlde lyase （HPL） are responsible for production of the signaling compounds, jasmonates and aldehydes respectively. Here, we compare and contrast the regulation of AOS and HPL branch pathways In rice and Arabidopsis as model monocotyledonous and dicotyledonous systems. These analyses provide new Insights Into the evolution of JAs and aldehydes signaling pathways, and the complex network of processes responsible for stress adaptations In monocots and dicots.
文摘Plant 9-1ipoxygenases （9-LOX） and α-dioxygenases （α-DOX） initiate the synthesis of oxylipins after bacterial infection. Here, the role of these enzymes in plants＇ defense was investigated using individual Arabidopsis thaliana Ioxl and doxl mutants and a double Ioxl doxl mutant. Studies with Pseudomonas syringae pv. tomato （Pst） revealed the enhanced susceptibility of Ioxl to the virulent strain Pst DC3000 and the partial impairment of Ioxl and doxl mutants to activate systemic acquired resistance. Notably, both defects were enhanced in the Ioxl doxl plants as compared with individual mutants. We found that pre-treatment with 9-LOX- and α-DOX-generated oxylipins protected plant tissues against bacterial infection. The strongest effect in this respect was exerted by 9-ketooctadecatrienoic acid （9-KOT）, which is produced from linolenic acid by 9-LOX. Quantification of 9-KOT revealed its accumulation after bacterial infection. The levels were reduced in Ioxl and Ioxl doxl plants but strongly increased in the doxl mutant due to metabolic interaction of the two pathways. Transcriptional analyses indicated that 9-KOT pre-treatment modifies hormone homeostasis during bacterial infection. The nature of the changes detected suggested that 9-KOT interferes with the hormonal changes caused by bacterial effectors. This notion was substantiated by the finding that 9-KOT failed to reduce the growth of PstDC3OOOhrpA, a mutant compromised in effector secretion, and of the avirulent strain Pst DC3000 avrRpml. Further support for the action of the 9-LOX- and α-DOX-oxylipin pathways as modulators of hormone homeostasis was the ob- servation that Ioxl doxl seedlings are hypersensitive to the growth-inhibitory effect of ABA and showed enhanced ac- tivation of ABA-inducible marker genes as compared with wild-type plants.
基金supported by the National Natural Science Foundation of China(Grant No.30000114,30270137)Natural Science Foundation of Guangdong Province(Grant No.039254,04020569&21043)
文摘To gain an understanding of the molecular ba-sis of signaling pathways in herbivore-induced maize plant defense, three key genes, ZmAOS, ZmAOC and ZmHPL, which are involved in the biosynthesis of oxylipin signals, have been cloned using RT-PCR in this study. Beet army-worm (BAW) infestation induced the systemic expression of the key genes involved in the biosynthesis of oxylipin signals similar to exogenous methyl jasmonate (MeJA). Moreover, the systemic expression patterns of maize defense-related genes were similar between maize leaves induced by jas-monic acid (JA) and damaged by BAW. Previous treatment with salicyhydroxamic acid (SHAM), an inhibitor of jas-monates (JAs) signal pathway followed by BAW infestation did not induce the systemic expression of the defense-related genes. Exposure to the vapors of green leafy volatiles (GLVs, (Z)-3-hexen-1-ol, (E)-2-hexenal, (E)-3-hexenal) and β-oci- mene induced the expression of the defense-related genes, as well as the key genes involved in biosynthesis of JAs. How-ever, previous treatment with SHAM clearly decreased the transcript levels of the defense genes induced by (Z)-3-hexen-1-ol, (E)-2-hexenal and (E)-3- hexenal. These results demonstrate the major role of oxylipin signal path-way in herbivore-induced maize chemical defense. JA was the endogenous signal in the process of herbivore-induced maize systemic defense. GLVs, another group of oxylipin, played an important role in the process of herbivore-induced systemic defense outside the plant. Furthermore, the expres-sion of defense-related genes induced by GLVs was partially dependent on JAs signal pathway, while β-ocimene induction was independent of JAs signal pathway.
