基于GC-MS代谢组学的大鼠肝脏代谢谱时序性变化的性别差异研究

考察性别因素对死后肝脏组织中代谢物变化规律的影响。72只SD大鼠（雌雄各半）于死后72 h内不同时间采集肝脏右叶,进行气相色谱－质谱联用（Gas chromatography－mass spectrometry,GC－MS）代谢组学分析。通过主成分分析（Principal component analysis,PCA）和偏最小二乘法（Partial least squares,PLS）进行多元统计分析,筛选出不同性别中均随死亡时间（Postmortem interval,PMI） 变化的共同差异代谢物,比较分析其在死后不同时间是否存在性别差异。结果显示,雌雄大鼠肝脏的不同PMI样本在PCA和PLS分析中均能完全区分,在雄性大鼠和雌性大鼠肝脏中分别筛选出了42种和41种与PMI相关的差异代谢物,其中31种为不同性别组共有的差异代谢物。在共有的差异代谢物中,有18种在死后不同时间点存在性别差异。该研究表明性别因素会对死后不同时间肝脏组织中代谢物的浓度产生影响,采用代谢物推断PMI时需考虑性别因素。     

基于1H-NMR的模式识别方法应用于异常黑胆质糖尿病患者的尿液代谢组学研究

探讨核磁共振氢谱结合模式识别方法应用于异常黑胆质糖尿病患者的尿液代谢组研究可行性。对32 例异常黑胆质糖尿病患者和29 例健康人尿液进行核磁共振氢谱检测,采用主成分分析(principal component analysis, PCA)、偏最小二乘法判别分析(partial least squares dis-criminant analysis, PLS-DA)、正交偏最小二乘法判别分析(orthogonal to partial least squares discriminant analysis,OPLS-DA)进行模式识别分析,比较3种模式识别方法的判别能力。运用3种模式识别均可以对2组数据进行有效的区分,但OPLS-DA较PCA、P[1]LS-DA更加有效,不仅提高了模式识别方法的判断能力,可以清楚的判断两组中有差异的代谢物。基于核磁共振氢谱结合模式识别分析方法可以为异常黑胆质糖尿病代谢标志物的寻找提供理论依据。OPLS-DA的模式识别方法较其它2种方法更具优势,在揭示维医理论本质上有着广阔的应用前景。     

基于气相色谱-飞行时间质谱技术的佐剂性关节炎大鼠尿液代谢组学的研究

采用弗氏完全佐剂(FCA)诱导佐剂性关节炎(AA)大鼠模型,观察大鼠足趾肿胀度和踝关节组织的病理学形态变化。应用气相色谱-飞行时间质谱(GC-TOF MS)技术检测AA大鼠尿液代谢物谱,并对数据进行主成分分析(PCA)、偏最小二乘法-判别分析(PLS-DA)及正交偏最小二乘法-判别分析(OPLS-DA),探讨可能的发病机制。通过变量重要性投影值(VIP>1)和P值(<0.05),筛选出尿液中的差异代谢物。在模型组大鼠的尿液中共发现异柠檬酸、α-酮戊二酸、柠康酸、肌酸、3-羟基丁酸等20种差异代谢物。推断AA代谢组学的发病机制可能与能量代谢、氨基酸代谢、脂肪酸代谢途径有关。     

基于液相色谱/电喷雾飞行时间质谱技术的结石症尿液代谢组学探讨

探索了一种简便的尿液样品前处理流程,通过反相液相色谱(RPLC)与亲水相互作用色谱(HILIC)相结合的高效液相色谱/电喷雾飞行时间质谱的联用技术(HPLC/ESI-TOFMS),建立了泌尿系结石症的尿液代谢组学模型,研究结石症患者尿液样品中的代谢物浓度水平与健康人对照组间的差异情况。采用主成分分析(PCA)及偏最小二乘法-判别分析(PLS-DA)等多变量数据分析方法,寻找结石症患者组和对照组之间的差异性代谢谱。模型结果显示:结石症患者尿液代谢物水平与健康对照组具有明显差异,寻找其中潜在的差异性标志物群组,有望将该模型用于泌尿系结石症的快速预测和诊断。     

格列美脲治疗的2型糖尿病大鼠的尿液代谢组学研究

采用快速高分离度液相色谱-质谱技术(RRLC-MS)检测经格列美脲治疗的2型糖尿病大鼠尿液中代谢物的变化, 对糖尿病组、 给药组和健康对照组大鼠的尿液代谢物谱进行了分析. 采用主成分分析(PCA)对3组大鼠进行分类并寻找潜在生物标记物. 结果表明, 3组大鼠的尿液代谢物谱得到了很好的区分, 发现并鉴定了2个潜在生物标记物, 分别为4-脱氧三羟基丁酸和4-胍基丁酸. 格列美脲对2型糖尿病大鼠的药物作用可能体现为对氨基酸代谢的调节作用.     

黄芪口服液降低大鼠顺铂毒性作用机制的尿液代谢组学研究

采用基于液相色谱-飞行时间质谱联用(LC-TOF-MS)技术的代谢组学方法,分析大鼠尿液内源性代谢物的变化,研究黄芪口服液(HO)降低大鼠顺铂(CDDP)毒性的作用机制.采用低剂量多次腹腔注射CDDP的方法建立CDDP染毒大鼠模型,并连续给予16天HO.于第18天收集正常对照(Control)组、顺铂模型(CDDP)组和黄芪口服液(HO)组大鼠的24 h尿液, 进行LC-TOF-MS分析,以获取尿液代谢物组数据集,对所得数据进行主成分分析(PCA)和正交偏最小二乘法-判别分析(OPLS-DA)等多元统计分析,以筛选潜在生物标志物.于第20天采集大鼠血清测定肌酐和尿素氮水平.血清指标测定结果表明, HO可以显著降低CDDP染毒大鼠的肌酐和尿素氮水平(p<0.05).PCA得分图显示,3组可分别聚类,HO组位于Control组和CDDP组中间,表明HO可部分改善CDDP所致大鼠尿液代谢产物的异常变化.综合OPLS-DA分析、t检验和倍数变化分析结果,最终共筛选并初步鉴定出35个尿液代谢产物作为HO减毒相关的潜在生物标记物.代谢通路分析结果表明,HO可通过纠正体内氨基酸代谢、能量代谢和核苷酸代谢等通路的紊乱,降低CDDP所致机体毒性.     

基于超高效液相色谱-高分辨质谱联用技术的桑黄干预后大鼠尿液代谢组学分析

为探讨服用桑黄水煎液对机体的影响,采用超高效液相色谱-高分辨质谱（UPLC-HDMS）联用技术,检测灌胃给予桑黄水煎液后大鼠尿液中代谢物的变化。采用正交偏最小二乘法判别分析（OPLS-DA）对空白组和给药组大鼠尿液代谢物进行聚类分析,筛选出潜在的生物标志物,并通过MetaboAnalyst 3.0网站分析相关代谢通路。数据显示,两组大鼠尿液中的代谢物在第28天得到了很好的区分,发现并鉴定了10个生物标记物。灌胃给予桑黄水煎液主要对机体的半胱氨酸和甲硫氨酸代谢、精氨酸和脯氨酸代谢、嘌呤代谢等代谢通路产生影响。研究结果为深入探讨桑黄药效作用机制奠定了一定的实验基础。     

非靶向尿液代谢组学方法研究五味子治疗精尿病并发症作用机制

采用超高效液相色谱-串联四级杆飞行时间质谱联用技术(Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry,UPLC/Q-TOF-MS),结合主成分分析技术(Principal component analysis,PCA),进行了五味子治疗糖尿病并发症大鼠尿液代谢组学研究,对五味子治疗糖尿病并发症大鼠后尿液生物标志物变化进行了考察.采用UPLC/Q-TOF-MS方法分析了健康组、糖尿病并发症模型组和五味子给药组的大鼠尿液,采用偏最小二乘法-判别分析(Partial least squares discriminant analysis,PLS-DA)和正交偏最小二乘法-判别分析(Orthogonal partial least squares discriminant analysis,OPLS-DA)载荷图筛选,通过分析对各组分离贡献较大(VIP>1,P°0.05)化合物的串联质谱数据,再经Human Metabolome Data-base(HMDB)等数据库检索,进行质谱信息匹配,尿液中共鉴定出28种潜在生物标记物,其中正谱13种,负谱15种.这些生物标记物主要影响戊糖和葡糖醛酸相互转化通路、核黄素代谢、泛酸和CoA合成、精氨酸和脯氨酸代谢、肠内菌代谢、嘌吟代谢、Vc代谢胆酸合成、色氨酸代谢等通路,五味子从能量代谢、氨基酸代谢、肠内菌代谢、脂类代谢等各个角度发挥治疗糖尿病并发症的作用.从各个通路的相关生物功能分析,五味子治疗糖尿病肾病的作用较强,此外还具有降脂、抗氧化的功效.     

基于快速高分辨液相色谱-质谱的中波紫外线辐射诱导大鼠急性光损伤的代谢组学研究

利用快速高分辨液相色谱-四极杆-飞行时间质谱( RRLC-Q-TOF-MS)联用技术结合多元统计分析方法,考察在中波紫外线( Ultraviolet B, UVB)辐射前后,大鼠尿液中内源性代谢物谱的变化,研究UVB辐射导致急性光损伤的生理机制。急性光损伤大鼠模型由窄谱中波紫外线光源(TL-01,峰值312 nm)照射,采用离心沉降后四倍稀释法处理尿液样本, Supelco Ascentis? Express C18色谱柱,水(含0.1％甲酸)与乙腈为流动相梯度洗脱,液相色谱-串联质谱分析测定。利用主成分分析( PCA)法、聚类分析( CA)法等对辐射前后的大鼠尿液样本进行代谢轮廓分析,寻找对分组贡献大的差异代谢物及通路,并阐明其作用机制;运用偏最小二乘判别分析( PLS-DA)法建立预测模型,考察此模型在UVB致光损伤模型诊断上的预测能力。多元统计分析结果显示,空白对照组与UVB模型组能够获得很好地区分,通过将差异代谢物与数据库、串联质谱数据及标准品比对,发现并鉴定出11种潜在生物标记物,表明UVB辐射可影响正常大鼠的鞘脂类代谢、核酸代谢、亚油酸代谢、氨基酸代谢等通路,这些差异代谢物对UVB辐射致光损伤类疾病的诊断具有较好的预判能力。     

基于超高效液相色谱-四极杆飞行时间质谱联用技术的血瘀模型大鼠血浆代谢组学分析

采用盐酸肾上腺素加冰水浴建立急性血瘀大鼠模型，使用超高效液相色谱-四极杆飞行时间质谱（UPLC-Q-TOF/MS）检测空白对照组与血瘀模型组中血浆代谢物，用主成分分析（PCA）、有监督偏最小二乘法判别分析（PLS-DA）及正交偏最小二乘法判别分析（OPLS-DA）对代谢组学数据进行多维统计分析，筛选潜在生物标志物。与对照组相比，在血瘀模型组大鼠血浆中检测出46个差异代谢物，血瘀模型组中乙酰胆碱、N6，N6，N6-三甲基-L-赖氨酸、胞嘧啶、乙酰肉碱等21个代谢物显著上调，吲哚丙酸、LysoPC（14：0）等25个代谢物显著下调，可能与脂质代谢、半乳糖代谢、亚油酸代谢、不饱和脂肪酸生物合成、糖酵解、花生四烯酸代谢等通路有关。代谢产物可作为血瘀证研究中的重要标记物，该研究结果有助于揭示血瘀证的发病机制，可为临床血瘀疾病的诊断及选用药物治疗提供思路，为后续治疗手段提供参考依据。     

1H NMR Combined with Multivariate Statistics for Discrimination of Female and Male Flower Buds of Populus tomentosa

¹H Nuclear Magnetic Resonance (¹H NMR) combined with multivariate statistics was adopted to discriminate female and male flower buds of Populus tomentosa in the study. Samples of 11 female and 16 male flower buds of P. tomentosa were collected in Beijing, China. ¹H NMR spectra were acquired on a 400 MHz spectrometer. In total, 30 chemical compounds were identified with standards and literature according to chemical shifts, peak areas, and multiplicity. Principal component analysis (PCA), hierarchical clustering analysis (HCA), and supervised orthogonal partial least squares-discriminant analysis (OPLS-DA) were applied to discriminate female and male flower buds. An apparent grouping trend (R²X, 0.809; Q², 0.903) between female and male groups was exhibited with PCA and HCA. The two groups were also well discriminated with OPLS-DA (R²X, 0.808; R²Y, 0.976; Q², 0.960). Combined with variable importance in projection (VIP) > 1.0 and p < 0.05 of OPLS-DA, it was found that the content of daucosterol, β-sitosterol, ursolic acid, and betulonic acid in male group was higher than that in female, which should be the key differences of chemical constituents in female and male flower buds of P. tomentosa. The study demonstrated that ¹H NMR combined with multivariate statistics could be used to discriminate female and male plants and clarify differences, which provided a novel method to identify the gender of dioecious plants.     

Simultaneous determination of MK-0767 and seven metabolites in rat urine using liquid chromatography/tandem mass spectrometry

MK-0767, 5-[2,4-dioxothiazolidin-5-yl)methyl]-2-methoxy-N-[[(4-trifluoromethyl)phenyl]methyl]benzamide (I, Table 1), is a dual peroxisome proliferator-activated receptor (PPAR) alpha/gamma agonist previously studied for the treatment of type 2 diabetes and dyslipidemia. To support further toxicological studies in one of the animal species used in chronic testing of I, a liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the simultaneous quantification of I and seven metabolites in rat urine was developed and validated. In this method, urine samples were diluted with acetonitrile/methanol (50:50, v/v) and injected directly onto the column of an LC system. Detection was achieved by MS/MS using a turbo ion spray probe monitoring precursor --> product ion combinations in selected reaction monitoring (SRM) mode. The linear range for I and three metabolites was 0.8-800 ng/mL, and 8-8000 ng/mL for four other metabolites found to be present in urine at higher concentrations than I. Intra-day and inter-day variation using this method were < or = 13.0%. The method exhibited good linearity, reproducibility, specificity and sufficient sensitivity when used for the analysis of rat urine samples. Concentrations of I and its major metabolites in rat urine were determined in samples collected between 0-24 h after dosing on the last day of administration of nine daily oral doses to three male (1000 mg/kg/day) and three female (300 mg/kg/day) Sprague-Dawley rats. The urinary concentrations of I and its metabolites were similar in male and female rats. The average concentrations of I were 0.51 and 0.33 microg/mL in male and female rats, respectively. Concentrations of four of the seven metabolites quantified were 6- to 45-fold higher than those of I. The most abundant metabolite, with concentrations of 24.2 and 13.3 microg/mL in male and female rat urine, respectively, was a methyl sulfoxide derivative formed by oxidative cleavage of the thiazolidinedione ring, followed by S-methylation and oxidation of the sulfide intermediate.     

基于超高效液相色谱-高分辨质谱和渗透压校正样本浓度变异性的尿液代谢组学分析

尿液是代谢组学研究中主要关注的体液样本之一。尿液样本中的代谢物浓度受饮食、疾病等因素影响变异较大,这极大阻碍了高质量组学数据的获取和可靠生物标志物的鉴定。研究为克服尿液样本的浓度变异性,在原始数据采集前,根据样本渗透压的大小,针对性地调整进样量或者稀释样本,从而确保代谢组学分析样本的渗透压与进样量的乘积相当,再经超高效液相色谱-高分辨质谱技术(UPLC-HRMS)分析,采用总离子丰度或总有用峰面积(MSTUS)对数据集进行归一化处理。研究利用临床样本及其梯度稀释的溶液,对该方法与现有研究普遍使用的方法进行了比较,随后通过先天性肾积水患者及健康志愿者的尿液样本做了进一步的方法学验证。数据集经校正后,峰面积RSD<30%的提取峰数量增加,主成分分析结果较校正前有更高的组内聚集和组间分群效应,正交偏最小二乘判别分析的统计模型更不易过拟合。与肌酐比较,渗透压值与质谱信号间呈现了更好的线性关系。以上结果表明,数据采集前通过样本渗透压进行校正,能有效消除因样本本身代谢物浓度变化引起的组内差异,提高方法的重复性和统计模型的可靠度。以渗透压为基准的校正策略,比肌酐校正法适用范围更广,结果也更准确。研究可对后续各类来源的尿液代谢组学研究提供数据归一化的指导和参考。     

基于化学模式识别技术的枳实HPLC定量指纹图谱研究

建立了枳实的高效液相色谱(HPLC)指纹图谱分析方法.色谱柱为Tnature-ACCHROM C18色谱柱(4.6 mmx250 mm,5 μm);以乙腈-0.5％甲酸水溶液为流动相进行梯度洗脱,结合液相色谱-四极杆飞行时间质谱(HPLC-QTOF-MS)联用技术对枳实指纹图谱中的共有峰进行鉴定;采用相似度评价、聚类分...     

Liquid chromatography/mass spectrometry for metabonomics investigation of the biochemical effects induced by aristolochic acid in rats: the use of information-dependent acquisition for biomarker identification

The toxic effects of oral administrations of nephrotoxic and carcinogenic aristolochic acid (AA) to male Sprague-Dawley rats were investigated by using high-performance liquid chromatography coupled with a quadrupole time-of-flight mass spectrometer. Analysis of the urine and plasma samples revealed distinct changes in the biochemical patterns in the AA-dosed rats. After peak finding and alignment, principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) were used for multivariate data analysis. Potential biomarkers were studied by high-resolution mass spectrometry (MS) and tandem mass spectrometry (MS/MS) analyses. The MS/MS spectra of all endogenous metabolites satisfying the pre-defined criteria were acquired in a single information-dependent acquisition (IDA) analysis, demonstrating that IDA was an efficient approach for structural elucidation in metabonomic studies. Citric acid and a glucuronide-containing metabolite were observed as potential biomarkers in rat urine. A significant increase in plasma creatinine concentration was also observed in the AA-dosed rats, which indicated that AA induced an adverse effect on the renal clearance function.     

Untargeted-metabolomics differentiation between poultry samples slaughtered with and without detaching spinal cord

Chicken meat is among the common and relatively inexpensive source of protein consumed worldwide from the poultry industry. Many communities show concern regarding the procedure of slaughtering animals for meat consumption due to ethical, religious, or cultural reasons. Liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) based untargeted metabolomics of 40 chicken meat samples were evaluated to differentiate meat samples based on slaughtering methods. Samples were grouped into, Zabiha (cutting neck without detaching spinal cord) and Non-Zabiha (completely detaching neck). A volcano plot reveals at least 150 features found significantly different between the two groups having ≥ 2-fold changes in intensities with p-values ≤ 0.05. Among them 05 identified and 25 unidentified metabolites have clear differences in peak intensities. The identified features can be employed to differentiate meat obtained from different slaughtering methods. A characteristic pattern based on principal component analysis (PCA) and orthogonal partial least square-discriminant analysis (OPLS-DA) was observed among the groups. The results will benefit Halal certification, food safety, and security agencies to curb food fraud.     

Development and validation of a gas chromatography/mass spectrometry metabonomic platform for the global profiling of urinary metabolites

This paper presents a simple and reliable gas chromatography/mass spectrometry (GC/MS) method for the metabonomic analysis of human urine samples. The sample preparation involved the depletion of excess urea via treatment with urease and subsequent protein precipitation using ice-cold ethanol. An aliquot of the mixture was separated, dried, trimethylsilyl (TMS)-derivatized and 1.0 microL of the derivatized extract was injected into the GC/MS system via split injection (1:10). Approximately 150 putative metabolites belonging to different chemical classes were identified from the pooled human urine samples. All the identified metabolites were selected to evaluate precision and stability of the GC/MS assay. More than 95% of the metabolites demonstrated good reproducibility, with intra-day and inter-day precision values below 15%. Metabolic profiling of 53 healthy male and female urine samples in combination with pattern recognition techniques was performed to further validate the GC/MS metabolite profiling assay. Principal component analysis (PCA) followed by orthogonal partial least squares analysis (OPLS) revealed differences between urinary metabolite profiles of healthy male and female subjects. This validated GC/MS metabolic profiling method may be further applied to the metabonomic screening of urinary biomarkers in clinical studies. Copyright (c) 2008 John Wiley & Sons, Ltd.