酵解与水解食用菌多糖对脾胃损伤小鼠调节作用的比较研究

目的 研究酵解与水解食用菌多糖对脾胃损伤小鼠的影响, 并比较二者对脾胃损伤小鼠的调节作用。方法 50只SPF级ICR小鼠, 分成空白组、模型组、阳性对照组、水解食用菌多糖组和酵解食用菌多糖组, 每组雌雄各半。采用高脂高糖加酒法建立脾胃损伤模型, 测定小鼠脏器指数、血清中超氧化物歧化酶(superoxide dismutase, SOD)、丙二醛(malondialdehyde, MDA)、一氧化氮(nitric oxide, NO)、肿瘤坏血因子(tumor necrosis factor-α, TNF-α)、白介素-6 (interleukin-6, IL-6)、胃泌素(gastrin, GAS)、胃动素(motilin, MTL)、二胺氧化酶(diamine oxidase, DAO)、谷丙转氨酶(glutamic-pyruvic transaminase, AST)、谷草转氨酶(glutamic-pyruvic transaminase, ALT)、肌酐(creatinine, CRE)和尿素氮(urea nitrogen, BUN)水平。利用主成分分析提取主成分并对各组间小鼠进行评分。结果 相较于模型组, 水解食用菌多糖与酵解食用菌多糖组GAS、MTL、SOD水平极显著上升(P<0.01), TNF-α、BUN、AST水平极显著降低(P<0.01), ALT水平显著降低(P<0.05), NO、IL-6、MDA、CRE、DAO水平呈显著或极显著降低(P<0.05或P<0.01)。主成分分析评分图显示, 不同组别的小鼠间有明显分离, 且与水解食用菌多糖组相比, 酵解食用菌多糖组和模型组之间的分离度更高。结论 酵解食用菌多糖和水解食用菌多糖均可通过提升机体免疫力和抗氧化能力, 改善脾胃损伤伴随的炎症反应及肝肾代谢功能, 且酵解食用菌多糖对小鼠的脾胃损伤具有更优的调节作用。     

UPLC-HRMS结合质谱分子网络高通量分析人血浆中的代谢物

本文建立了超高效液相色谱-高分辨质谱（UPLC-HRMS）结合质谱分子网络（MSMN）分析血浆中代谢物的方法。采用Folch方法提取血浆中的代谢物,运用UPLC-HRMS技术同时检测水相和有机相中的多种代谢物。以标准品准确定性的代谢物为种子化合物,采用MSMN筛选与种子化合物质谱特征相似的代谢物,扩展代谢物定性范围,提高代谢物定性效率。将该方法用于人血浆中代谢物的定性分析,共检测到187个代谢物。其中,在水相中定性检测到氨基酸、脂肪酸、糖类等80个代谢物,在有机相中定性检测到107个脂类代谢物,实现了人血浆中多类代谢物的高通量分析。     

Small Molecule Metabolite Biomarker Candidates in Urine from Mice Exposed to Formaldehyde

Formaldehyde (FA) is a ubiquitous compound used in a wide variety of industries, and is also a major indoor pollutant emitted from building materials, furniture, etc. Because FA is rapidly metabolized and endogenous to many materials, specific biomarkers for exposure have not been identified. In this study, we identified small metabolite biomarkers in urine that might be related FA exposure. Mice were allowed to inhale FA (0, 4, 8 mg/m³) 6 h per day for 7 consecutive days, and urine samples were collected on the 7th day of exposure. Liquid chromatography coupled with time of flight-mass spectrometry and principal component analysis (PCA) was applied to determine alterations of endogenous metabolites in urine. Additionally, immune toxicity studies were conducted to ensure that any resultant toxic effects could be attributed to inhalation of FA. The results showed a significant decrease in the relative rates of T lymphocyte production in the spleen and thymus of mice exposed to FA. Additionally, decreased superoxide dismutase activity and increased reactive oxygen species levels were found in the isolated spleen cells of exposed mice. A total of 12 small molecules were found to be altered in the urine, and PCA analysis showed that urine from the control and FA exposed groups could be distinguished from each other based on the altered molecules. Hippuric acid and cinnamoylglycine were identified in urine using exact mass and fragment ions. Our results suggest that the pattern of metabolites found in urine is significantly changed following FA inhalation, and hippuric acid and cinnamoylglycine might represent potential biomarker candidates for FA exposure.     

Effects of Different Short-Term UV-B Radiation Intensities on Metabolic Characteristics of Porphyra haitanensis

The effects of ultraviolet (UV) radiation, particularly UV-B on algae, have become an important issue as human-caused depletion of the protecting ozone layer has been reported. In this study, the effects of different short-term UV-B radiation on the growth, physiology, and metabolism of Porphyra haitanensis were examined. The growth of P. haitanensis decreased, and the bleaching phenomenon occurred in the thalli. The contents of total amino acids, soluble sugar, total protein, and mycosporine-like amino acids (MAAs) increased under different UV-B radiation intensities. The metabolic profiles of P. haitanensis differed between the control and UV-B radiation-treated groups. Most of the differential metabolites in P. haitanensis were significantly upregulated under UV-B exposure. Short-term enhanced UV-B irradiation significantly affected amino acid metabolism, carbohydrate metabolism, glutathione metabolism, and phenylpropane biosynthesis. The contents of phenylalanine, tyrosine, threonine, and serine were increased, suggesting that amino acid metabolism can promote the synthesis of UV-absorbing substances (such as phenols and MAAs) by providing precursor substances. The contents of sucrose, D-glucose-6-phosphate, and beta-D-fructose-6-phosphate were increased, suggesting that carbohydrate metabolism contributes to maintain energy supply for metabolic activity in response to UV-B exposure. Meanwhile, dehydroascorbic acid (DHA) was also significantly upregulated, denoting effective activation of the antioxidant system. To some extent, these results provide metabolic insights into the adaptive response mechanism of P. haitanensis to short-term enhanced UV-B radiation.     

代谢组学中机器学习研究进展

以往代谢组学的综述都着眼于对其应用情况进行总结,而对机器学习方法的对比研究不多。为此,在分析讨论目前机器学习方法在代谢组学研究方面最新进展的基础上,对各种机器学习方法及在代谢组学研究上的应用效果进行了总结,给出了代谢组学研究所使用的数据源,比较了各方法的应用效果及其利弊,指出目前代谢组研究中存在的主要问题及可能的改进方案。列举了相关方法在疾病诊断、药物开发等方面的最新应用,展望了代谢组学的研究前景,以期为改进代谢组学研究中机器学习算法的研究工作提供启示和帮助。     

HPLC-MS代谢组学研究中基质效应的尿液处理方法考察

The purpose of the present work was the evaluation of matrix effects due to the sample preparation approaches using RRLC-ESIMS technique. The result shows that urine dilution has the least relative matrix effect. Additionally, in an effort to reduce sample preparation time for high throughput studies and avoid analyte losses, urine dilution is more suitable to urinary metabonomic research.     

Molecular and Metabolic Mechanism of Low-Intensity Pulsed Ultrasound Improving Muscle Atrophy in Hindlimb Unloading Rats

Low-intensity pulsed ultrasound (LIPUS) has been proved to promote the proliferation of myoblast C2C12. However, whether LIPUS can effectively prevent muscle atrophy has not been clarified, and if so, what is the possible mechanism. The aim of this study is to evaluate the effects of LIPUS on muscle atrophy in hindlimb unloading rats, and explore the mechanisms. The rats were randomly divided into four groups: normal control group (NC), hindlimb unloading group (UL), hindlimb unloading plus 30 mW/cm² LIPUS irradiation group (UL + 30 mW/cm²), hindlimb unloading plus 80 mW/cm² LIPUS irradiation group (UL + 80 mW/cm²). The tails of rats in hindlimb unloading group were suspended for 28 days. The rats in the LIPUS treated group were simultaneously irradiated with LIPUS on gastrocnemius muscle in both lower legs at the sound intensity of 30 mW/cm² or 80 mW/cm² for 20 min/d for 28 days. C2C12 cells were exposed to LIPUS at 30 or 80 mW/cm² for 5 days. The results showed that LIPUS significantly promoted the proliferation and differentiation of myoblast C2C12, and prevented the decrease of cross-sectional area of muscle fiber and gastrocnemius mass in hindlimb unloading rats. LIPUS also significantly down regulated the expression of MSTN and its receptors ActRIIB, and up-regulated the expression of Akt and mTOR in gastrocnemius muscle of hindlimb unloading rats. In addition, three metabolic pathways (phenylalanine, tyrosine and tryptophan biosynthesis; alanine, aspartate and glutamate metabolism; glycine, serine and threonine metabolism) were selected as important metabolic pathways for hindlimb unloading effect. However, LIPUS promoted the stability of alanine, aspartate and glutamate metabolism pathway. These results suggest that the key mechanism of LIPUS in preventing muscle atrophy induced by hindlimb unloading may be related to promoting protein synthesis through MSTN/Akt/mTOR signaling pathway and stabilizing alanine, aspartate and glutamate metabolism.     

果蔬酚酸生物合成及代谢调控研究进展

酚酸类物质是高等植物体内广泛分布的一类重要的次生代谢产物,具有抗氧化、抗炎、抗癌、抑菌、提高 免疫力等多种生物活性。近年来,大量的研究表明酚酸与植物生长发育及抗逆性、食品质量和人体健康密切相关, 有关植物酚酸的分离鉴定及生物合成途径已有广泛研究。本文综述了果蔬中酚酸的生物合成途径和酚酸与果蔬抗逆 性及品质间的关系,并对代谢组学在评价酚酸类物质分布规律中的应用进行了阐述,以期为酚酸类物质在果蔬中的 开发利用提供有益参考。     

基于LC/MS的代谢组学数据并行处理研究

代谢组学是继基因组学和蛋白质组学之后生命科学研究领域一个新的分支,液相色谱-质谱（LC/MS）联用技术是代谢组学研究过程中广泛使用的一种代谢物检测方法。为快速处理LC/MS联用仪在检测过程中产生的大量原始数据,本研究将原始数据分组后由不同的计算节点完成预处理工作,提出了基于数据并行的预处理方法;为提高并行效率,提出了谱峰预识别算法。实验表明：27个小鼠血清样本原始数据在5个计算节点上分组并行处理,按照保留时间平均划分的加速比为2.87,按照谱峰平均划分的加速比为4.55;经大量数据和更多计算节点测试,数据并行处理方法比单计算节点串行处理方法的速度有很大提高,谱峰并行模式加速比S_p趋近于理想加速比P。该方法能够快速、准确地处理代谢组学研究过程中产生的海量数据。