NMR分析胶质瘤细胞系CHG5和U87的代谢轮廓

胶质瘤是中枢神经系统最常见的恶性肿瘤,其发病原因和恶性进展机制均不明确,给胶质瘤的临床诊疗带来很大困难.胶质瘤恶性进展伴随着癌细胞代谢改变,但可以反映胶质瘤恶性进展的代谢物信息和分子机制目前仍不清楚.该研究以两种不同恶性程度的胶质瘤细胞系CHG5和U87为研究对象,用基于NMR的代谢组学方法分析这两种胶质瘤细胞系的代谢轮廓,寻找差异性代谢物.结果表明CHG5和U87的代谢轮廓存在明显差异.在高恶性程度的U87细胞中,柠檬酸盐(citrate)等15种代谢物有上升趋势;而乳酸盐(lactate)、牛磺酸(taurine)等6种代谢物有下降趋势.以上结果表明这些差异性代谢物可能与胶质瘤细胞的恶性特性密切相关.这些从胶质瘤细胞系获取的代谢信息将成为临床标本代谢组学研究的重要前提和有益补充.     

NMR 分析胶质瘤细胞系CHG5 和U87 的代谢轮廓

胶质瘤是中枢神经系统最常见的恶性肿瘤，其发病原因和恶性进展机制均不明确，给胶质瘤的临床诊疗带来很大困难．胶质瘤恶性进展伴随着癌细胞代谢改变，但可以反映胶质瘤恶性进展的代谢物信息和分子机制目前仍不清楚．该研究以两种不同恶性程度的胶质瘤细胞系CHG5 和U87 为研究对象，用基于NMR 的代谢组学方法分析这两种胶质瘤细胞系的代谢轮廓，寻找差异性代谢物．结果表明CHG5 和U87 的代谢轮廓存在明显差异．在高恶性程度的U87 细胞中，柠檬酸盐(citrate)等15 种代谢物有上升趋势；而乳酸盐(lactate)、牛磺酸(taurine)等6 种代谢物有下降趋势．以上结果表明这些差异性代谢物可能与胶质瘤细胞的恶性特性密切相关．这些从胶质瘤细胞系获取的代谢信息将成为临床标本代谢组学研究的重要前提和有益补充．     

莽草酸途径中26种代谢物的NMR谱归属

莽草酸代谢途径广泛存在于植物、微生物与某些寄生虫中,是芳香氨基酸、植物激素与多种重要活性次生代谢物的主要合成通路.这些代谢物的系统核磁共振（NMR）研究尚不完备,且5-羟基吲哚乙酸与吲哚乳酸等代谢物的NMR数据归属尚不完整.本文对莽草酸代谢途径介导的26种代谢物（包括2种非芳香羧酸、2种植物激素、3种芳香类氨基酸、19种植物次生代谢物）结构进行了较为系统的NMR分析,对这些代谢物的¹H和¹³C NMR信号进行了归属,为植物化学及代谢组学研究提供了基础数据.     

三种氘标记的葡萄糖在大鼠脑胶质瘤细胞中的代谢特征对比

磁共振氘(²H)成像是近年来涌现出的一种能在活体水平下实现特定代谢通路可视化的分子代谢成像方法,在癌症检测等重大疾病方面具有极好的临床应用前景．本文分析了三种不同氘标记葡萄糖——[6,6’-²H₂]-葡萄糖、[2,3,4,6,6’-²H₅]-葡萄糖和[1,2,3,4,5,6,6’-²H₇]-葡萄糖在脑胶质瘤细胞中的代谢特征差异．将大鼠脑胶质瘤C6细胞与三种氘标记的葡萄糖一起孵育,收集不同时刻细胞培养基样品,采用核磁共振波谱仪对样品进行核磁共振氘谱采集,获取不同时间三种氘标记葡萄糖的消耗量以及下游代谢产物水和乳酸的产量,从而得出三种氘标记葡萄糖探针在肿瘤细胞中的消耗速度以及代谢物的生成速度等动态代谢特征．结果显示在细胞实验中三种氘标记葡萄糖均能够显示出肿瘤细胞的代谢特征,且葡萄糖的消耗速度并无显著性差异,氘标记水和氘标记乳酸的产量也符合理论估算．因此本文认为低成本的氘标记葡萄糖探针[2,3,4,6,6’-²H     

JAK/STAT通路抑制剂对C57BL/6小鼠血清代谢组影响的1H NMR研究

JAK/STAT通路抑制剂已被应用于多种疾病的临床试验,但其全身性用药对机体组织细胞功能活性的影响目前尚不明确.本研究运用基于核磁共振氢谱（¹H NMR）的代谢组学方法分析了JAK/STAT通路抑制剂WP1066（20 mg/kg.bw,2天一次,持续2周）对C57BL/6小鼠血清代谢组的影响.首先采用¹H NMR技术检测了WP1066处理组和对照组小鼠血清的代谢物,然后对所得的图谱数据进行了主成分分析（PCA）以及正交偏最小二乘法分析（OPLS）.研究结果表明,抑制JAK/STAT通路可明显下调小鼠血清中的N-甲基烟酰胺（N-methylnicotinamide）水平,而上调顺乌头酸（cis-aconitate）、草酰乙酸（oxaloacetate）和乙酰胺（acetamide）水平,这些代谢物改变均与能量代谢密切相关.该结果提示代谢失衡相关指标可能作为JAK/STAT通路抑制剂治疗的临床监测参考指标.     

电离辐射对小鼠肾脏影响的代谢组学研究

电离辐射对生物体影响是目前生物医学领域研究的热点之一.本文利用基于核磁共振氢谱（¹H NMR）的代谢组学技术研究来自暴露于不同的电离辐射的C57BL/6J小鼠的肾脏的水溶性萃取物,并试图寻找电离辐射对小鼠肾脏影响的特异性生物标志物.分析结果表明,辐射组可与相应的对照组明显区分.在所发现的75个代谢物中,有6种代谢物的浓度发生显著性变化,分别为2-氨基丁酸、3-羟基丁酸、高丝氨酸、1,3-丙二胺、β-丙氨酸和抗坏血酸.这些代谢物可能成为高剂量电离辐射对生物体肾脏代谢影响的标志物.     

1H MRS评价长期胰岛素治疗1型糖尿病大鼠海马代谢物的变化

本研究应用质子磁共振波谱（¹H MRS）技术对链脲佐菌素（STZ）诱导的1型糖尿病（T1DM）大鼠及长期胰岛素治疗的T1DM大鼠单侧海马的代谢物进行了分析. 结果发现,与对照组大鼠及胰岛素治疗组大鼠相比,T1DM模型组大鼠空腹血糖显著升高,体重显著降低（p < 0.05）.T1DM模型组肌醇（Ins）、牛磺酸（Tau）与谷氨酸（Glu）浓度较对照组显著升高（p = 0.000、p = 0.003、p = 0.014）.胰岛素治疗组Ins与Tau浓度较T1DM模型组显著降低（p = 0.000、p = 0.010）,与对照组无差别;而Glu、谷氨酸和谷氨酰胺（Glx）浓度较对照组显著升高（p = 0.007、p = 0.042）.本文结果表明T1DM大鼠海马区代谢物Ins浓度与Tau浓度对胰岛素治疗敏感.     

基于影像的形态学特征与胶质母细胞瘤特征分子表达的相关性研究

本文探讨了磁共振成像（MRI）形态学指标与胶质母细胞瘤（GBM）特征分子表达率的相关性,为GBM的临床评估、个性化治疗方案的选择及预后评价提供了影像学参考依据.首先回顾性分析了我院60例经手术病理证实的GBM的MRI数据,测量计算出肿瘤区最长径（TLD）、水肿区最长径（ELD）、强化与肿瘤长径比例（CTE/TLD）3个形态学指标.同时,进行免疫组化染色,得到GBM的表皮生长因子受体（EGFR）、异柠檬酸脱氢酶-1（IDH-1）、抑癌基因TP53、磷酸酶-张力蛋白（PTEN）和神经丝轻链（NEFL）特征性变化,根据染色程度与瘤细胞阳性细胞的比率的乘积进行评分.然后,对TLD、ELD和CTE/TLD与上述分子表达分别进行Pearson相关分析和多元logistic回归分析.结果标明TLD与EGFR、PTEN表达呈正相关（r=0.796、r=0.533）,与IDH-1表达呈负相关（r=-0.672）.CTE/TLD与EGFR、PTEN表达呈正相关（r=0.622、r=0.638）,与IDH-1表达呈负相关（r=-0.493）.ELD与5个特征分子的表达均无显著相关性.因此,基于MRI的肿瘤形态学分析能够在一定程度上反应肿瘤特征分子的差异,对GBM的分子分级和预后判断可提供直观的影像学参考依据.本文结果显示常规MRI测量肿瘤形态学指标有可能成为一种较为简便直观的胶质瘤分级与预后评估手段.     

靶向肿瘤因子c-MYC基因启动区G4-DNA的小分子药物设计及核磁共振研究进展

肿瘤基因MYC在人类70%癌细胞中高表达,抑制其转录是治疗肿瘤的有效手段.c-MYC启动子区P1近端的核酸酶超敏元件Ⅲ₁(NHE Ⅲ₁)控制MYC基因近90%的转录激活.NHE Ⅲ₁区域富含碱基G序列并且形成G-四链体(G4),调控c-MYC基因转录,是抗肿瘤药物靶标.但G4-DNA和G4-RNA的三维结构高度相似,小分子与其他G4(如端粒G4、mRNA G4、c-Kit G4等)的非特异性作用会产生小分子药物“脱靶”效应,同时小分子药物会诱导其他G4形成从而干扰正常细胞的功能,造成靶向c-MYC G4抗癌药物设计困难.本文综述了近些年靶向肿瘤因子c-MYC G4-DNA的小分子药物研究进展,及核磁共振(NMR)技术在G4-DNA和G4-RNA结构确定中的作用,为靶向c-MYC G4-DNA的小分子药物设计等相关研究工作提供参考.     

肝肿瘤细胞HepG2代谢指纹及代谢足迹的NMR分析

细胞代谢特征的分析是认识细胞生物化学过程物质基础的一个关键点. 该文使用培养72 h的肝肿瘤细胞HepG2为模型,使用一维与二维核磁共振谱学分析方法, 分析了该细胞本身及其培养液中代谢物的组成,确定了50余种覆盖三羧酸循环、糖酵解、氨基酸合成、脂肪酸与胞膜代谢、嘌呤与嘧啶代谢等多个代谢途径的代谢物,发现细胞本身与培养基中代谢物组成能够分别提供“细胞代谢指纹”与“细胞代谢足迹”等互补性信息. 同时发现此方法可用于研究植物次生代谢物槲皮素对肝肿瘤细胞HepG2代谢的影响. 结果表明,核磁共振波谱技术是分析细胞代谢组特征和研究药物对细胞代谢影响规律的有效手段.     

Differential responses of cancer cell lines to non-thermal plasma from dielectric barrier discharge

The differential responses of six cancer cell lines after treatment of non-thermal plasma from dielectric barrier discharge (DBD) were studied. Two plasma exposure methods including cell suspension exposure and media only exposure were used, and the effects were examined in six cancer cell lines including KB, MCF-7, HeLa, H460, SNU-80 and T98G from different human organs. The result indicates that both methods affected six cell lines similarly in proliferation, mitochondria activity, and apoptosis related gene expression, which implies that the cell culture media have significant role in plasma–cell interaction. H460 showed a significant reduction in cell number after plasma exposure, whereas MCF-7 showed less reduction. Mitochondria activity of all the cancer cell lines reduced following exposure and incubation times except MCF-7. The mRNA expression of Bax, the apoptosis related gene, was highly enhanced in KB, HeLa, MCF-7 and SNU-80, while none was detected in T98G. All six cancer cell lines showed unexpectedly low mRNA expression of tumor suppressor gene p53. These differential responses of six cell lines suggest that non-thermal plasma should activate different pathways in each cancer cell line. Further researches on tissue-specific responses to plasma treatment should be conducted, comparing their responses with normal tissue–cell responses.     

Spectral intensities in the ν1 band of NH3

Intensities have been measured for individual transitions in the Q and R branches of the ν₁ band of NH₃ using a difference-frequency laser spectrometer. The data yield an integrated band strength of S⁰_v=219.36±1.03 cm^-2/MPa at 297 K, corresponding to a transition moment of μ_v = 8.535(20) × 10^-32 C·m, and a Herman-Wallis correction factor, (1 + _jm)², where _j = 0.0209(20). The intensities of a few lines for K 7 were noticeably perturbed by a perpendicular Coriolis interaction with 2ν₄ (E, L = 2), so were excluded from the fit. A small sample of ν₃ band lines occurring in the ν₁ band scans also yields a rough estimate of the ν₃ band intensity with evident irregular perturbations.     

Critical behavior of transverse and longitudinal ac susceptibilities in a random anisotropy magnet a-Dy16Fe84

We have investigated critical lines in the H-T plane in a random anisotropy magnet (RAM) a-Dy₁₆Fe₈₄ with a small effective ratio of the anisotropy (D) to the exchange constant (J) by means of ac susceptibility (χ) in static fields H parallel and perpendicular to the ac field. We found that the transverse χ exhibits an anomaly along the irreversible line H(T_f) determined by previous magnetization measurements, while the longitudinal χ does so along a characteristic line H(T_i) in a lower temperature region. Above H(T_f) we also found an extra characteristic line H(T_c). The lines were almost independent of the measured frequency. Both the present results and previous magnetization results suggest that an equilibrium phase transition occurs, and the critical lines analogous to those in Heisenberg spin glasses are present in a weak RAM.     

Meerwein酯与苯相互作用的1H NMR研究

测定了Meerwein酯(1,3,5,7,-四羧甲基二环[3,3,1]壬-2,6-二烯-2,6-二醇)在四氯化碳和苯混合溶剂中随苯的摩尔分数变化的¹H NMR谱.观察到分子中两类不同的甲基的化学位移随苯的摩尔分数增加都逐渐移向高场,分子中不同位置上的甲基的化学位移向高场移动程度不同,原处低场的甲基的δ比原处高场甲基的δ要大,两条吸收峰在苯的摩尔数渐增时先是重合后又渐渐分开,所有化学位移可以用线性方程δ=A+BX表示.     

Metabolite mapping of human filarial parasite, Brugia malayi with nuclear magnetic resonance

Metabolite mapping of human filarial parasite, Brugia malayi was carried out in vitro as well as in situ in host Mastomys coucha by ³¹P nuclear magnetic resonance (NMR) spectroscopy. Detection of parasites by visualizing contrast spots due to pathologic changes was observed by ¹H magnetic resonance imaging (MRI). Major metabolites of adult B. malayi observed by ³¹P-NMR spectroscopy were of sugar phosphates (SP), phosphomonoesters (PME), glycerophosphoryl-ethanolamine (GPE), -choline (GPC), phosphoenolpyruvate (PEP), inorganic phosphate (Pi), nucleoside diphosphosugar and nucleotides-mono, -di and -tri phosphates. PEP and GPC were present in high concentration; PEP being the major energy reservoir and GPC the major phospholipid in this species of filaria. The ³¹P NMR spectra of testis of mastomys, showed seven major peaks of SP, PME, phosphocreatine (PCr), phosphodiesters (PDE), Pi, and nucleotides di- and tri-phosphates. The ³¹P-NMR spectra of testis of B. malayi infected animal also consisted of seven major peaks with significant decrease in the SP and PME peak showing changes in the carbohydrate and lipid metabolism of filaria infected testis. Thus, in vivo ³¹P MRS provided a non-invasive assessment of tissue bioenergetics and phospholipid metabolism.     

Pinning model derived from resistive measurements on melt processed Bi2Sr2CaCu2O8

On melt processed samples of the 86 K superconductor Bi₂Sr₂CaCu₂O₈ we have performed resistive measurements in the low field limit B0.13 T and 40 KT77 K. The voltage drop is found to rise exponentially with current E ∝exp j/j₀, which is interpreted in terms of thermal activation of pinned flux lines. An activation energy U₀(T)90 meV is derived from the transition width j₀(T) and is related to a plausible core pinning interaction of flux lines with normal conducting precipitates. This reproduces the measured j_c(B, T) values in the whole regime investigated. We conclude that pinning centers must have a minimum size in order to control flux creep. Finally we demonstrate that conventional summation of the single site pinning forces cannot account for the observed macroscopic depinning current density.     

应用FTIR研究模式植物拟南芥和烟草甲醛代谢机理的差异

运用FTIR技术分析模式植物拟南芥和烟草在甲醛胁迫条件下体内各物质含量的变化规律及光谱表征,为推定两种植物甲醛代谢机理的差异提供线索。拟南芥红外光谱中1 376 cm-1的纤维素峰没有出现在烟草样品中。在应对甲醛胁迫时,它的强度值下降趋势比其他吸收峰小,说明拟南芥体内的甲醛主要流向氧化生成甲酸和CO₂的途径。胁迫后期该吸收峰强度值下降,而其他物质的峰持续上升,说明该途径中相关酶基因的表达可能受到甲醛抑制,而其他途径的酶基因表达不受影响。烟草用甲醛处理后红外光谱中各化学成分的含量变化趋势一致,说明甲醛进入各代谢途径的流量差别不大。第4天时烟草红外光谱各吸收峰的强度值再次下降是其甲醛代谢能力较弱结果,表明烟草对甲醛的抗性不如拟南芥强。     

Hyperfine fields at Y nuclei in Y(Fe1−xTx)3 (T = Al, Co)

The spin echo spectra of ⁸⁹Y hyperfine fields in Y(Fe_1−xT_x)₃ with low concentration x consist of two main lines and of satellite lines caused by the replacement of the Fe atoms by the T atoms. Values of the magnetic moments of the T atoms are estimated by observing the satellite lines.