| Background:PM2.5(particulate matter with an aerodynamic diameter of less than 2.5 μm)is the most well-studied form of air pollution.Its chemical composition is complex and has a greater impact on health than coarse particulate matter due to its large surface area adsorption.China is one of the world’s largest emitters of man-made air pollution,with outdoor air pollution levels among the highest in the world.PM2.5 is the major air pollutant in China.The complex composition of PM2.5 mediates oxidative stress.genotoxicity,inflammatory response and immune imbalance,causing health damage to human body.Carbon aerosols account for the majority of PM2.5 in urban air pollution and contribute to more health damage(20-50%).Organic aerosols in carbon aerosols mainly come from the primary source and secondary transformation of volatile organic compounds(VOCs).Therefore,AS an important precursor of secondary organic aerosols and an important component of OC,its pathological characteristics and metabolic mechanism are also an important link in PM2.5 research.In addition,the combination of traditional Chinese medicine of patients with multiple targets,accept degree is high,and the advantages of small side effects,can react by reducing oxidative stress,anti-inflammation and immune regulation imbalance,reach the role of prevention and treatment of PM2.5 health damage,but the current clinical use of Chinese medicine compound prevention and cure of fog to lung injury is still belongs to the exploration stage,the lack of evaluation mechanism of effect of biological monitoring indicators.Based on the preliminary observation and network pharmacology analysis,the research group believed that fang Qingfei Jianghaze Soup prepared by the department may have a biological effect of reducing haze health,but the specific effect is still unclear.Metabolomics is an important technical method to explore the metabolic changes of small molecules in living organisms.The large number of chemicals measured in PM2.5 exposed biological samples fill the gap between genome and environmental interactions.The application of metabolomics in PM2.5 research can help researchers to have a broader understanding of the changes of proteins in response to environmental exposure,so as to identify potential biomarkers and metabolic pathways of PM2.5 exposure,and provide more clues for related mechanisms.Objective:In study 1,a portable air purifier was used to construct an intervention model of natural exposure-purition-reexposure-repurification in healthy subjects.Combined with targeted urine thioglyuric acid detection and genomics,the metabolic characteristics of VOCs urine metabolite thioglyuric acid were comprehensively understood and explored.In the second study,a randomized controlled single blind trial was designed to screen out urine mercaptouric acid as a biological detection index of PM2.5 exposure,to conduct clinical verification of the scientific nature of TCM Compound Qingfei Jianghaze Decoction in the intervention of haze exposure,and to expand the application of TCM compound in the prevention and treatment of PM2.5-related health damage.In study 3,untargeted metabolomics analysis was performed on urine samples in study 1 design,and PM2.5 urine metabolism profile was plotted,providing more possibilities for understanding and scientific prevention and control of PM2.5.Methods:In study 1,the urine of 50 healthy subjects was quantitatively analyzed based on targeted metabolomics,and the trend of the changes in the natural exposuredecontamination reexposure-repurification model was observed.The Sequenom MassARRAY platform was used to conduct primer extended mass spectrometry genotyping for 47 SNPS screened based on previous work.The correlation between SNPS and MAs metabolism was explored based on the above two parts of data,and KEGG gene-function analysis was performed.In study 2,84 healthy non-smoking subjects were included in a 7-day randomized controlled single blind trial during fine particle pollution period to compare the metabolism level of sulfhydryurate in urine before and after intervention and evaluate the clinical application value of Qingfei Jianghaze Decoction in the prevention and treatment of health injury caused by haze.In study 3,GC-MS untargeted metabolome analysis was performed on urine samples collected from 50 people at 5 time points.PCA,supervised partial least squares analysis(PLS-DA)and orthogonal partial least squares analysis(OPLS-DA)were used to better distinguish metabolic differences and analyze metabolic profiles.The differential weight contribution value(VIP)of the first principal component was calculated according to the OPLS-DA model,and the False positive rate(FDR)P value of each metabolite in the semi-quantitative analysis between groups was calculated by T test to determine the differential metabolite between groups,and KEGG metabolic pathway enrichment analysis was performed.The obtained metabolomics data can be used to construct ROC curves for screening potential biomarkers associated with PM2.5 exposure in clinical samples and for SMPDB enrichment analysis.Differential metabolites with opposite metabolic trends were further screened for PM2.5-related differential metabolites,which could be used as biomarkers of PM2.5 short-term exposure.Results:In study 1,we compared the changes of urine mercaptouric acid metabolism at different time points,and found that outdoor air pollution(PM2.5)exposure was closely correlated with the urine levels of five targets of mercaptouric acid(CEMA,SPMA.HMPMA,HPMA,HEMA).CEMA is a sensitive biomarker of ULTRA-short-term exposure to PM2.5.SPMA is more suitable for biological evaluation of air purification efficiency,while HMPMA,HPMA and HEMA are stable and persistent in PM2.5 exposure,which are more suitable for biological monitoring over time.Sequenom SNP typing data was used to screen out a total of 14 SNPS that were correlated with the metabolic ability of 5 kinds of urine MAs,among which GSTP1 and EPHX1 genes played a core role in screening the SNP gene-metabolic network related to the metabolic ability of urine MAs.The metabolism of cytochrome P450 to exogenous substances,Hippo signaling pathway,oxidative phosphorylation,asthma and other pathways were associated with the metabolism of target 5 urine MAs.TLR4 gene(rs10759931,RS10759932)was associated with SPMA,TP63 gene(rs4488809,RS4600802)was associated with CEMA metabolic capacity.G allele of RS10759931,C allele of RS10759932 can promote SPMA excretion,T allele of RS4488809,C allele of RS4600802 can protect human body by promoting CEMA excretion.In study 2,the difference between HEMA(Z=-3.614,P<0.001)and HMPMA(Z=-1.988,P=0.047)in the experimental group was significantly greater than that in the control group after 7 days of TCM compound Qingfei Jianghaze Decoction intervention.After controlling urine concentration before intervention,HEMA in experimental group was significantly higher than that in control group(F=7.597,P=0.007).Qingfei Jianghaze Decoction significantly increased HEMA excretion in urine.Research based on GC-MS non targeted metabolomic methods selected 10 common enrichment of KEGG pathways,including alanine,aspartic and glutamic acid metabolism,arginine and proline metabolism,acetaldehyde and dicarboxylic acid metabolism,GSH metabolism,arginine biosynthesis and metabolism of butyrate(intestinal),glycine,serine and threonine metabolism,Pyrimidine metabolism,porphyrin and chlorophyll metabolism,histidine metabolism,D-glutamine and Dglutamate metabolism and nitrogen metabolism,among which d-glutamine and Dglutamate metabolism and alanine metabolism contributed the most to the metabolic difference.The metabolites of 2,3-dihydroxypyridine(AUC=0.932)and glucoheptanoic acid(AUC=0.936)with significant changes between groups were screened by univariate ROC curve,which has extremely high diagnostic value.Five metabolites were identified as ornithine,glycine,(2R)-2-amino-3-phosphonopropionic acid,creatine and ethanolamine,which were closely related to PM2.5 exposure.Among them,glycine FC(C/Po1)=2.9012,FC(Po1/Pu1)=0.26548,ornithine FC(C/Po1)=2.6291,FC(Pol/Pul)=0.28201 were more obvious than other metabolites.Conclusion:1.Short-term PM2.5 exposure can produce significant metabolic changes in human body,which is closely related to oxidative stress,genotoxicity,energy disturbance and other mechanisms.2 GSTP1 and EPHX1 genes play a core role in KEGG genes-metabolic network of mercaptouric acid metabolism,TLR4 genes(RS10759931,RS10759932).TP63 genes(rs4488809,RS4600802)are associated with the metabolism of volatile organic compounds.3 Through a randomized controlled single blind trial,it was found that the intervention of Chinese herbal compound Qingfei Jianghaze Decoction could significantly increase the excretion of ethylene oxide metabolite HEMA in urine of healthy people in Beijing area during PM2.5 exposure,and enhance the detoxification process of toxic components in PM2.5,which has practical application value in haze prevention and treatment.4.Five differential metabolites were selected that were significantly correlated with PM2.5 exposure changes,among which ornithine and glycine could be used as biomarkers for monitoring PM2.5 transient exposure and diagnosing PM2.5-related health damage. |
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