Spatiotemporal pharmacometabolomics based on ambient mass spectrometry imaging to evaluate the metabolism and hepatotoxicity of amiodarone in HepG2 spheroids / 药物分析学报

Three-dimensional(3D)cell spheroid models combined with mass spectrometry imaging(MSI)enables innovative investigation of in vivo-like biological processes under different physiological and patho-logical conditions.Herein,airflow-assisted desorption electrospray ionization-MSI(AFADESI-MSI)was coupled with 3D HepG2 spheroids to assess the metabolism and hepatotoxicity of amiodarone(AMI).High-coverage imaging of＞1100 endogenous metabolites in hepatocyte spheroids was achieved using AFADESI-MSI.Following AMI treatment at different times,15 metabolites of AMI involved in N-desethylation,hydroxylation,deiodination,and desaturation metabolic reactions were identified,and according to their spatiotemporal dynamics features,the metabolic pathways of AMI were proposed.Subsequently,the temporal and spatial changes in metabolic disturbance within spheroids caused by drug exposure were obtained via metabolomic analysis.The main dysregulated metabolic pathways included arachidonic acid and glycerophospholipid metabolism,providing considerable evidence for the mechanism of AMI hepatotoxicity.In addition,a biomarker group of eight fatty acids was selected that provided improved indication of cell viability and could characterize the hepatotoxicity of AMI.The combination of AFADESI-MSI and HepG2 spheroids can simultaneously obtain spatiotemporal infor-mation for drugs,drug metabolites,and endogenous metabolites after AMI treatment,providing an effective tool for in vitro drug hepatotoxicity evaluation.

Exploration and advance of key techniques in MALDI mass spectrometry imaging / 药学学报

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is a new imaging technique with label-free, rapid, and high throughput features. It has bloomed in the analysis on the spatial distribution of biomolecules such as drugs, metabolites, peptides and proteins on the tissue surface in virtue of providing high data throughput from non-targeted full analysis and high accuracy from targeted analysis. The acquisition of MSI signal response with high sensitivity, high spatial resolution, and good stability is directly depended on the appropriate sample preparation approaches, and flexible and various data processing tools will help the non-target data mining to meet the demands of visualization, spatial distribution and multiple index applications so as to reveal the scientific rules beneath the data. This review briefly summarizes the key advances in MALDI-MSI from aspects of sample preparation procedures, data processing and visualization. It also illustrates the characteristics, difficulties and probable solutions derived from these key techniques.

Spatiotemporally resolved metabolomics and isotope tracing reveal CNS drug targets

Deconvolution of potential drug targets of the central nervous system (CNS) is particularly challenging because of the complicated structure and function of the brain. Here, a spatiotemporally resolved metabolomics and isotope tracing strategy was proposed and demonstrated to be powerful for deconvoluting and localizing potential targets of CNS drugs by using ambient mass spectrometry imaging. This strategy can map various substances including exogenous drugs, isotopically labeled metabolites, and various types of endogenous metabolites in the brain tissue sections to illustrate their microregional distribution pattern in the brain and locate drug action-related metabolic nodes and pathways. The strategy revealed that the sedative-hypnotic drug candidate YZG-331 was prominently distributed in the pineal gland and entered the thalamus and hypothalamus in relatively small amounts, and can increase glutamate decarboxylase activity to elevate γ-aminobutyric acid (GABA) levels in the hypothalamus, agonize organic cation transporter 3 to release extracellular histamine into peripheral circulation. These findings emphasize the promising capability of spatiotemporally resolved metabolomics and isotope tracing to help elucidate the multiple targets and the mechanisms of action of CNS drugs.

Recent advances in mass spectrometry imaging and its application in drug research / 中国药科大学学报

@#Mass spectrometry imaging (MSI), a label-free molecular imaging technique, has been applied widely in the spatial localization of small molecule metabolites, lipids, peptides, and proteins, with its unique advantage of high spatial resolving power compared to traditional liquid chromatography-mass spectrometry (LC-MS).With the nonstop advancement of its achievable sensitivity and spatial resolution, MSI technique has been providing novel perspectives into the preclinical studies of drugs, such as in vivo localization of drugs and their metabolites, visualization of drug metabolism, and drug delivery tracking.This review introduces the basics of MSI techniques, including basic principles, key features, technical advantages, and limitations, with particular highlight of the recent applications of MSI in drug efficacy and safety evaluation, drug distribution research, drug delivery research, and analysis of Chinese medicine from recent publications, aiming to promote the utilization and further expansion of MSI in the research and development of drugs.

Application of Matrix-assisted Laser Desorption Ionization Mass Spectrometry in Analysis of Traditional Chinese Medicine：A Comprehensive Review / 中国实验方剂学杂志

Traditional Chinese medicine （TCM）， which owns abundant chemical components and complex action pathways， has been widely recognized in the prevention and treatment of diseases. Some analysis methods have been emerged in order to ensure the quality of TCM and to develop new TCM drugs. Matrix-assisted laser desorption ionization mass spectrometry （MALDI-MS） is a soft ionization mass spectrometric technique with the advantages of high throughput， high sensitivity， low cost and so on. It provides technical support for the molecular level study on TCM. At present， this technique has been used in the field of composition analysis and metabonomics research of TCM， and plays an important role in the identification of Chinese herbal medicines， real-time molecular screening and the construction of metabolic network pathway of active ingredients. Among them， the selection of appropriate matrix and sample preparation technology is the key to ensure the detection effect of MALDI-MS. With the development and optimization of new matrix， the continuous improvement of sample preparation technology and the combination of MALDI-MS with various analytical methods will greatly improve the detection effect. Based on this， this paper discusses the application of MALDI-MS in TCM， including high-throughput detection of active ingredients in TCM， monitoring of the original medicines and their metabolites in vivo， and in situ visualization and characterization of tissue distribution information of active ingredients in TCM. It also discusses the application prospect and existing problems of MALDI-MS in TCM， so as to provide technical support for the identification of active ingredients in TCM， drug utilization and metabolism.

Study of mass spectrometry imaging metabolomics of paclitaxel based on esophageal cancer multicellular tumor spheroids cultured in vitro / 药学学报

Multicellular tumor spheroids (MCTS) can simulate the structure and metabolic characteristics of tumors in vivo, which is of great significance to study the metabolic phenotype of tumor cells and the mechanism of drug intervention. In this study, esophageal cancer MCTS were constructed, and MCTS frozen sections were prepared after treated with different formulations of paclitaxel (PTX) including common PTX injection, PTX liposome and albumin bound PTX. MCTS mass spectrometry imaging analysis method was established by using air flow assisted desorption electrospray ionization mass spectrometry imaging (AFADESI-MSI). The visualization of the permeation and enrichment process of PTX in MCTs after PTX treatment was realized, and the spatially resolved metabolomics of PTX injection group was studied. The results showed that the permeation and enrichment behavior of PTX in MCTs model were related to the formulations. The changes of endogenous metabolites in MCTs of esophageal cancer after treated with PTX injection had temporal and spatial characteristics. The metabolic changes of MCTS during the initial 0-4 hours were dominated by the down-regulation of middle-high polarity metabolites and some lipids in the central region of MCTS, while the metabolic changes of MCTS during 8-72 hours were mainly up-regulated by lipid metabolites in the peripheral region of MCTS. The combination of in vivo tumor-associated MCTs model with label free, highly sensitive and high coverage mass spectrometry imaging technology provided a new method and strategy for the study of pharmacometabolomics.

Spatial distribution characteristics of metabolities in rhizome of Paris polyphylla var. yunnanensis: based on MALDI-MSI / 中国中药杂志

In this study, a method was established for in-situ visualization of metabolite distribution in the rhizome of Paris polyphylla var. yunnanensis. To be specific, through matrix-assisted laser desorption/ionization-mass spectrometry imaging(MALDI-MSI), the spatial locations of steroidal saponins, amino acids, organic acids, phytosterols, phytoecdysones, nucleosides, and esters in rhizome of the medicinal plant were directly analyzed, and six unknown compounds with differential distribution in rhizome tissues were identified. The specific procedure is as follows: preparation of rhizome tissue section, matrix screening and optimization, and MALDI-MSI analysis. The results showed that the steroidal saponins were mainly distributed in the central, amino acids in epidermis and cortex, low-molecular-weight organic acids in central epidermis, phytosterols in the epidermis and lateral cortex, the phytoecdysones in epidermis and cortex, nucleosides(uneven distribution) in epidermis and cortex, growth hormones around the epidermis and cortex, particularly outside the cortex, and esters in cortex with unobvious difference among different tissues. In this study, the spatial distribution of meta-bolites in the rhizome of P. polyphylla var. yunnanensis was characterized for the first time. The result can serve as a reference for identifying and extracting endogenous metabolites of P. polyphylla var. yunnanensis, exploring the synthesis and metabolism mechanisms of the metabolites, and evaluating the quality of medicinal materials.

Mass Spectrometry Imaging and Its Application in Forensic Toxicology / 法医学杂志

Mass spectrometry imaging （MSI） is a new imaging technology that can simultaneously detect and record the spatial distribution information of multiple molecules on the sample surface without labeling. The main principle of MSI is to combine mass spectrometry with imaging technology and irradiate the sample slice with ion beam or laser to ionize the molecules on its surface, obtain the mass spectrometry signal through the detector, convert the obtained data into pixel points by the imaging software, and then construct the spatial distribution image of the target compound on the tissue surface. The sample preparation for MSI include： sample collection and storage, tissue section, tissue pretreatment, selection and application of matrix. At present, this technology has been widely used in the fields of biomedicine, new drug development and proteomics, and its application in the field of forensic toxicology has also gradually attracted attention. This article reviews the principles and sample preparation process of MSI, describes the application of MSI in abused substances and metabolites of various material matrices, herbal mixtures, latent fingerprints, hair and animal and plant tissues, and discusses the prospects of the application of this technology in forensic toxicology, in order to provide ideas and references for the application of MSI technology in forensic toxicology.

Application of DESI-MSI in Quality Control of Banxia Xiexintang / 中国实验方剂学杂志

Objective::To prepare 15 batches of Banxia Xiexintang substance benchmark and lyophilized powder from different places, and the lyophilized powder was analyzed by ultra-high performance liquid chromatography with diode array detection (UHPLC-DAD) and desorption electrospray ionization-mass spectrometry imaging (DESI-MSI) in order to investigate the advantages of DESI-MSI in quality control of famous classical formulas. Method::Taking Banxia Xiexintang as the research model, fingerprints of the substance benchmark and lyophilized powder were established by UHPLC-DAD, and the content of index components and the yield of dry extract were also investigated. Meanwhile, as the research carrier, the lyophilized powder corresponding to Banxia Xiexintang was dissolved in methanol and dotted on qualitative filter paper with 5 μL quantitative capillary, and fixed it on the slide to make samples. The samples were analyzed on a DESI-MSI system in positive and negative ion mode with methanol-formic acid (1 000∶1, flow rate of 3 μL·min-1) as spray solvent, N2 as spray gas (pressure of 0.5 MPa). The scanning range was 100-1 200 Da, the spatial resolution was 300 μm, the spray voltage was 3 kV, the sampling cone voltage was ±40 V, incidence angle of sprayer was 60 degree, its collection angle was 10 degree, the ion source temperature was 120 ℃. Result::DESI-MSI could not only detect the index components of liquiritin, baicalin and wogonoside, as well as the common peaks of liquiritin apioside, berberine and glycyrrhizic acid, but also analyzed them semi-quantitatively, the analysis results were basically consistent with UHPLC-DAD. At the same time, DESI-MSI could detect 16 other components from Glycyrrhizae Radix et Rhizoma, Coptidis Rhizoma, Scutellariae Radix, Jujubae Fructus and Ginseng Radix et Rhizoma, such as licoricesaponin G2, palmatine, coptisine, rutin and ginsenoside Rg1, and present their relative content visually. The qualitative analysis ability of DESI-MSI was much better than UHPLC-DAD. Conclusion::DESI-MSI can be used as the quality control method for substance benchmark and lyophilized powder and dispensing granules of famous classical formulas with advantages of high sensitivity, strong analytical ability, no complex sample processing, qualitative and relative content analysis of complex samples without reference substance.

Study on application of DESI-MSI in quality control of classical famous prescription Shaoyao Gancao Decoction / 中草药

Objective: Using ultra-high performance liquid chromatography with diode array detection (UHPLC-DAD) and desorption electrospray ionization-mass spectrometry imaging (DESI-MSI) to analyze 15 batches of Shaoyao Gancao Decoction (SGD) substance benchmark and lyophilized powder in order to investigate the advantages of DESI-MSI in quality control of famous classical formulas. Methods: Taking SGD as the research model, fingerprints of the substance benchmark were established by UHPLC-DAD, and the content of index components (paeoniflorin, liquiritin, glycyrrhizic acid) and the yield of dry extract were also investigated. Meanwhile, as the research carrier, the lyophilized powder corresponding to SGD was dissolved in methanol and dotted on qualitative filter paper with quantitative capillary, and fixed it on the slide to make samples. The samples were analyzed on a DESI-MSI system in positive and negative ion mode with methanol-formic acid (1 000:1, flow rate of 3 μL/min) as spray solvent, N2 as spray gas (pressure of 0.5 MPa). The scanning range was m/z 100-1 200, the spatial resolution was 300 μm, the ion source temperature was 120 ℃. Results: DESI-MSI can detect not only the index components of paeoniflorin, liquiritin, glycyrrhizic acid, but also the common peaks of albiflorin. At the same time, DESI-MSI could detect 11 other components from Glycyrrhizae Radix et Rhizoma and Paeoniae Radix Alba, such as licoricesaponin G2, licoricesaponin J2, gallic acid, citric acid, p-hydroxybenzoic acid, and present their relative content visually. The qualitative analysis ability of DESI-MSI was much better than UHPLC-DAD. Conclusion: DESI-MSI can be used as the quality control method for substance benchmark and lyophilized powder and dispensing granules of classical famous formulas with advantages of high sensitivity, strong analytical ability, no complex sample pretreatment, qualitative and relative content analysis of complex samples without reference substance.

Research progress on the regulation of tumor metabolism, tumor immunotherapy and new analytical methods / 药学学报

In order to achieve rapid proliferation and adapt to the complex microenvironment, tumor cells have dominant characteristics such as unique metabolic patterns and the ability to escape from immunoregulation. Tumor cells reprogram multiple metabolic pathways to promote immune escape, which impacts tumor diagnosis, treatment and prognosis. Based on the effect of metabolic changes on tumor immune escape and its molecular mechanism, metabolic regulation provides new approaches to enhance immunotherapy. We review recent advances in tumor immuno-escape and immunotherapy based on metabolic regulation. Cutting-edge analytical techniques and methods for tumor metabolism research such as metabolomics, mass spectrometry imaging-based spatially-resolved metabolomics and metabolic flow analysis are also discussed.

Analytical capabilities of matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) and its potential applications in medicinal plants / 药学学报

Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI), as a label-free imaging technique with high coverage and sensitivity is widely used for visualizing the spatial distribution of proteins, peptides and small metabolites in tissues. With the development of MALDI technique, MALDI-MSI is also employed to monitor the spatial distribution of phytochemical constituents of medicinal plants. In this review, we first briefly introduce MALDI-MSI technique, and we focus on its application in the spatial distribution and accumulation of secondary metabolites in medicinal plants. The ultimate advantage of using MALDI-MSI for spatial distribution analysis at the molecular level, offers crucial evidence of synthesis, transfer and accumulation of bioactive molecules in medicinal plants.

Metal/Matrix Enhanced Time-of-Flight Secondary Ion Mass Spectrometry for Single Cell Lipids Analysis / 分析化学

The chemical components analysis of single cell is important for understanding of physiological processes such as cell growth, signal transduction and apoptosis.Time-of-flight secondary ion mass spectrometry ( ToF-SIMS) is a sensitive surface analysis technique with high spatial resolution and can be used for single cell and micro-area analysis.However, relatively low ioniZation yield of biomolecules limited its wide application in single cell analysis.Herein, we used metal substrate and matrix material to enhance the ioniZation yield of lipids.The signal intensity of the phosphatidylcholine PC (40:0) casted on the matrix/gold coated silicon substrate was 65 times higher than that on the silicon wafer.Signal enhancement of phosphatidylcholine PC (34:1) on the single cell surface cultured on matrix/gold coated silicon substrate was observed as well.Due to the influence of irregular topography and complex chemical environment of cell, the increase of lipids signal was smaller.Delayed extraction mode of ToF-SIMS overcame the effects of cell topography, leading to further enhancement of the signal intensity of lipids.Meanwhile, simultaneous high spatial resolution of chemical imaging and high mass resolution of the mass spectra of single cells were obtained.Our strategies provided new insights into the study of cell metabolism and cell-environment interactions.

Cardioprotective effect of Danshen injectable powder on pressure overload-induced ventricular remodeling in rats and isoproterenol induced myocardial injury in mice / 中国药理学与毒理学杂志

OBJECTIVE To determine the effects of Danshen injectable powder on myocardial remodeling in pressure overload rats and isoproterenol(ISO)injection mice.METHODS SD Rats were subject to abdominal aortic constriction(AAC)surgery to develop pressure overload.Therapeutic effect of Danshen injectable powder was assessed six weeks after AAC surgery. The lactic dehydrogenase (LDH) and creatine kinase (CK) levels in serum, biometric, echocardiographic parameters, interstitial fibrosis, the expression of DJ-1 and SOD2 were then measured. The myocardial impairment in mice was induced by ISO injection. LDH and CK in serum, biometric, interstitial fibrosis were measured to investigate the cardioprotective effect of Danshen injectable powder. Matrix-assisted laser desorption mass spectrometry imaging(MALDI-MSI)was used to detect the changes of 60-1000 Da molecules in mice heart tissue. RESULTS In AAC rats, we observed compensatory hypertrophy and perivascular fibrosis,however cardiac function had not progressed to deterioration.The levels of LDH and CK were decreased significantly in the Danshen injectable powder groups(P<0.05,P<0.05).Danshen injectable powder could alleviate the perivascular collagen deposits but not cardiac hypertrophy in AAC rats. Furthermore,Danshen injectable powder enhanced the expression levels of SOD2 and DJ-1 in cardio-myocytes (P<0.05, P<0.01). In ISO injection mice, the levels of HWI and LDH were decreased signifi-cantly in drug treatment group compared with model group (P<0.01, P<0.01). In the MALDI-MSI of mice heart section,Danshen injectable powder can improve the reduction of energy metabolism-related substances including adenosine, creatine and ADP induced by ISO impairment. CONCLUSION Danshen injectable powder can attenuate perivascular fibrosis and improve the expression of anti-oxidative stress-related proteins SOD2,DJ-1 in the rats with pressure overload-induced left ventricular remodeling.Danshen injectable powder has cardioprotective effect on ISO impairment in mice which is probably related to improvement of energy metabolism.

Advances in mass spectrometry-based approaches for neuropeptide analysis / 生物工程学报

Neuropeptides are an important class of endogenous bioactive substances involved in the function of the nervous system, and connect the brain and other neural and peripheral organs. Mass spectrometry-based neuropeptidomics are designed to study neuropeptides in a large-scale manner and obtain important molecular information to further understand the mechanism of nervous system regulation and the pathogenesis of neurological diseases. This review summarizes the basic strategies for the study of neuropeptides using mass spectrometry, including sample preparation and processing, qualitative and quantitative methods, and mass spectrometry imagining.

Rhein:a novel matrix for profiling and imaging of endogenous metabolites by matrix-assisted laser desorption/ionization-mass spectrometry / 中国药科大学学报

@#MALDI-MS is an emerging technique that enables rapid profiling of endogenous substances in a high throughput. Nevertheless, its application to metabolite analysis is often hindered by the presence of massive matrix background peaks using conventional matrices. Herein rhein was introduced as a novel matrix for MALDI-MS analysis of cation metabolites. Several strong and weak basic metabolites were measured using rhein. Compared to the previously reported ionless matrix NSA and conventional matrix CHCA, clean MALDI-MS spectra were obtained devoid of matrix signals. Subsequently, we applied this matrix to profile a biologically complex sample, mice intestinal contents. In addition, we have validated the applicability of rhein to MALDI-MS imaging, which allows for simultaneous mapping of hundreds of metabolites from single mouse ileum section. In summary, the discovery of rhein as a novel MALDI matrix enables efficient and reliable profiling and imaging of endogenous metabolites from biological samples with no matrix interferences, which will greatly promote the utility of MALDI-MS-based platform for metabolome studies.

Mass spectrometry assessment of the protective effects of Zhizi Dahuang decoction on alcoholic liver injury / 中国药科大学学报

Liquid-assisted surface desorption atmospheric pressure chemical ionization mass spectrometry (LA-DAPCI-MS)was used directly for the analysis of healthy rat liver (normal control group);acute alcoholic injury rat liver(alcohol model group)and Zhizi Dahuang decoction-treated rat liver (ZZDHD group)sections with the mass spectrometry images obtained simultaneously.Principal component analysis (PCA)was employed for the differentiation of livers of the groups;and 3 phospholipids;PC (34 ∶2);PC(36 ∶4)and PC(38 ∶4);were found to be the main factors.LA-DAPCI mass spectrometry images showed that the 3 phospholipids were evenly distrib-uted in liver under the spatial resolution of 0.01 mm2.Contents of 3 PCs in the model group were decreased in alcohol model group compared to the normal control group and the ZZDHD group;which revealed the relationship between acute alcoholic liver injury and intrahepatic phospholipid variation.The results showed that ZZDHD had protective effect on acute alcoholic liver injury-induced intrahepatic phospholipid variations at the molecular level.