LC-MS analysis of key components of the glutathione cycle in tissues and body fluids from mice with myocardial infarction

Exogenous cystine increases susceptibility of drug-resistant Salmonella to gentamicin by promoting oxidation of glutathione metabolism and imbalance of intracellular redox levels

Introduction

Antibiotic overuse has caused the development of bacterial resistance, which is a major threat to public health. Intracellular metabolic processes are essential for maintaining the normal physiological activities of bacteria, and an increasing body of research has demonstrated a significant association between metabolic alterations and the development of drug resistance. Numerous studies have demonstrated that the addition of adjuvants can counteract bacterial antibiotic resistance.

Method

Cystine treatment was verified in vitro to promote the lethal effect of gentamicin on Salmonella using in vitro bactericidal counting methods. The metabolic differences in Salmonella enterica Typhimurium standard strain ATCC 14028 with or without the addition of cystine were analyzed via untargeted metabolomics. The multifunctional electronic enzyme marker was used to determine intracellular reduced glutathione/oxidized glutathione (GSH/GSSG), ferrous iron on (Fe2+), and reactive oxygen species (ROS) levels. The expression of glutathione and stress genes was determined using real-time quantitative PCR.

Result

We confirmed that exogenous cystine increased the lethal effect of gentamicin against strain S. enterica Typhimurium (ATCC 14028) and other clinically resistant Salmonella serotypes. Exogenous cystine stimulated the metabolism of the cell and activated the glutathione pathway while altering the GSH/GSSG ratio, which placed bacteria in a state of redox imbalance with increased Fe2+ and ROS levels. Our results suggest that when bacterial redox levels are reprogrammed, bacterial susceptibility to antibiotics can also change.

Discussion

This study confirms that cystine enhances the antimicrobial efficacy of gentamicin against drug-resistant Salmonella. Through the application of metabolomics, the underlying metabolic mechanisms by which cystine exerts its effects on Salmonella have been elucidated, offering a novel perspective in the domain of metabolic reprogramming aimed at counteracting drug resistance. Furthermore, these findings reinforce the potential role of small-molecule metabolites as effective adjuvants to enhance antibiotic action.

Simultaneous Quantitation of Multiple Biological Thiols Using Reactive Ionization and Derivatization with Charged Mass Tags

The biologically important thiols (cysteine, homocysteine, N-acetyl cysteine, and glutathione) are key species in redox homeostasis, and there is a clinical need to measure them rapidly, accurately, and simultaneously at low levels in complex biofluids. The solution to the challenge presented here is based on a new derivatizing reagent that combines a thiol-selective unit to optimize the chemical transformation and a precharged pyridinium unit chosen to maximize sensitivity in mass spectrometry. Derivatization is performed simultaneously with ionization ("reactive ionization"), and mass spectrometry is used to record and characterize the thiol reaction products. The method is applicable over the concentration range from 1 μM to 10 mM and is demonstrated for 25 blood serum, 1 plasma, and 3 types of tissue samples. The experiment is characterized by limited sample preparation (<4 min) and short analysis time (<1 min). High precision and accuracy (both better than 8%) are validated using independent HPLC-MS analysis. Cystine-cysteine redox homeostasis can be monitored by introducing an additional reduction step, and the accuracy and precision of these results are also validated by HPLC-MS.

Disruption of canonical AHR-mediated induction of hepatocyte PKM2 expression compromises antioxidant defenses and increases TCDD-induced hepatotoxicity

Metabolic reprogramming by the pyruvate kinase M2 isoform is associated with cell proliferation and reactive oxygen species (ROS) defenses. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), an environmental contaminant that induces ROS and hepatotoxicity, dose-dependently induces pyruvate kinase muscle isoform M2 (PKM2) in the liver. To further investigate its role in combating TCDD hepatotoxicity, a PkmΔDRE mouse was constructed lacking the dioxin response element mediating aryl hydrocarbon receptor (AHR) induction. TCDD failed to induce hepatic PKM2 in PkmΔDRE mice and in primary hepatocytes isolated from an AHR knockout model (AHRV375Afl/flAlb-CreERT2), demonstrating induction is AHR dependent. Both wild-type (WT) and PkmΔDRE mice exhibited dose-dependent increases in liver weight after treatment with TCDD every 4 days for 28 days. Glutathione (GSH) levels increased in WT mice while oxidized glutathione (GSSG) levels increased in both models with a 24-fold decrease in the GSH/GSSG ratio in PkmΔDRE mice suggesting lower antioxidant and recycling capacity. Moreover, TCDD-induced fibrosis was more severe in PkmΔDRE mice while PkmΔDRE hepatocytes exhibited greater cytotoxicity following co-treatment with TCDD and hydrogen peroxide. TCDD also induced PKM2 in human HepaRG™ cells with AHR enrichment at a conserved DRE core within the locus. These results suggest AHR-mediated PKM2 induction is a novel antioxidant response to TCDD.

Investigation of the regulatory mechanisms of Guiqi Yimu Powder on dairy cow fatty liver cells using a multi-omics approach

Introduction

Fatty liver disease in dairy cows is a metabolic disorder that significantly affects their health and productivity, imposing a notable economic burden on the global dairy industry. Traditional Chinese medicine (TCM), characterized by its multi-component and multi-target features, has shown unique advantages in the prevention and treatment of various diseases. Guiqi Yimu Powder, a traditional TCM formula, enhances growth, boosts production efficiency, and strengthens immune function in livestock by regulating antioxidant along with anti-inflammatory pathways. However, its specific regulatory mechanisms on fatty liver in dairy cows remain unclear. This study aims to investigate the molecular-level effects and potential regulatory mechanisms of Guiqi Yimu Powder in a Trimethylamine N-oxide (TMAO) induced fatty liver cell model of dairy cows.

Methods

We employed a comprehensive analysis integrating transcriptomics, proteomics, metabolomics, and network pharmacology. An in vitro dairy cow fatty liver cell model was established using TMAO to induce lipid accumulation. Cells were treated with the optimal TMAO concentration identified through preliminary experiments, and further divided into a lipid accumulation group and Guiqi Yimu Powder treatment groups. The treatment groups received varying concentrations of Guiqi Yimu Powder (10, 20, 30, 40, or 50 g/L). High-throughput omics sequencing technologies were utilized to perform a comprehensive analysis of the treated cells. Bioinformatics methods were applied to explore the regulatory effects, aiming to elucidate the specific impacts of Guiqi Yimu Powder on lipid metabolism, liver function, and related signaling pathways, thereby providing scientific evidence for its potential application in the prevention and treatment of fatty liver in dairy cows.

Results

Guiqi Yimu Powder treatment significantly affected 1,536 genes, 152 proteins, and 259 metabolites. KEGG enrichment analysis revealed that the significantly altered molecules are involved in multiple pathways related to the pathology of fatty liver, including metabolic pathways, glutathione metabolism, hepatitis B, and AMPK signaling pathway (p < 0.05). Notably, joint analysis highlighted the regulatory mechanisms of Guiqi Yimu Powder on glutathione cycling, with L-5-Oxoproline identified as an important metabolic compound. These findings indicate its impact on oxidative stress, energy metabolism, and liver function, suggesting potential therapeutic applications for fatty liver in dairy cows.

Discussion

This study elucidated the regulatory mechanisms of Guiqi Yimu Powder on fatty liver cells in dairy cows, providing new scientific evidence for its potential application in the prevention and treatment of fatty liver disease.

Metabolomic changes in culture media with varying passage numbers of pig muscle stem cell culture for cultured meat production

Selecting the primary cells in an optimal state for cultured meat production is a crucial challenge in commercializing cultured meat. We investigated the metabolomic changes in culture media according to passage numbers for indirectly assessing the state of primary cells. Pig skeletal muscle stem cells (PSCs) harvested from the biceps femoris muscles of 7-d-old crossbred pigs (Landrace × Yorkshire × Duroc, LYD) were used for cell characterization. Fresh media (FM) and spent media (SM) of PSCs during passages 1 to 3 in vitro culture were prepared for metabolomics analysis. SM was collected on the third day of proliferation for each passage of PSCs. Cell characterization analysis revealed that the proliferation rate was highest at passage 2; however, a significant loss of expression of myogenic marker genes was observed at passage 3. Based on metabolomic profiles of culture media, FM and SM groups (SM1, SM2, and SM3) were clearly separated by partial least squares-discriminant analysis. A total of seven differentially abundant metabolites (DAMs) were identified from FM and SM for each passage, based on the following criteria: P < 0.05, fold change > 1.5 or < 0.66, and a variable importance in projection score > 1.5. All seven DAMs and their interconnected metabolites might be primarily used as substrates for energy production and most of them were relatively abundant in SM3. Among the seven DAMs, the three potential biomarkers (γ-glutamyl-L-leucine, cytosine, and ketoleucine), which showed significant changes exclusively in SM3, each had an area under the curve value of 1. Therefore, monitoring the levels of these key metabolites in culture media could serve as a quality control measure for cultured meat production by enabling the indirect detection of suboptimal PSCs based on their proliferation ability.

Cystine/Glutamate Xc- Antiporter Induction Compensates for Transsulfuration Pathway Repression by 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) to Ensure Cysteine for Hepatic Glutathione Biosynthesis

Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been associated with the induction of oxidative stress and the progression of steatosis to steatohepatitis with fibrosis. It also disrupts metabolic pathways including one-carbon metabolism (OCM) and the transsulfuration pathway with possible consequences on glutathione (GSH) levels. In this study, complementary RNAseq and metabolomics data were integrated to examine the hepatic transsulfuration pathway and glutathione biosynthesis in mice following treatment with TCDD every 4 days for 28 days. TCDD dose-dependently repressed hepatic cystathionine β-synthase (CBS) and cystathionine γ-lyase (CTH) mRNA and protein levels. Reduced CBS and CTH levels are also correlated with dose-dependent decreases in hepatic extract hydrogen sulfide (H2S). In contrast, cysteine levels increased consistent with the induction of Slc7a11, which encodes for the cystine/glutamate Xc- antiporter. Cotreatment of primary hepatocytes with sulfasalazine, a cystine/glutamate Xc- antiporter inhibitor, decreased labeled cysteine incorporation into GSH with a corresponding increase in TCDD cytotoxicity. Although reduced and oxidized GSH levels were unchanged following treatment due to the induction of GSH/GSSG efflux transporter by TCDD, the GSH:GSSG ratio decreased and global protein S-glutathionylation levels in liver extracts increased in response to oxidative stress along with the induction of glutamate-cysteine ligase catalytic subunit (Gclc), glutathione synthetase (Gss), glutathione disulfide reductase (Gsr), and glutathione transferase π (Gstp). Furthermore, levels of ophthalmic acid, a biomarker of oxidative stress indicating GSH consumption, were also increased. Collectively, the data suggest that increased cystine transport due to cystine/glutamate Xc- antiporter induction compensated for decreased cysteine production following repression of the transsulfuration pathway to support GSH synthesis in response to TCDD-induced oxidative stress.

Effects of medwakh smoking on salivary metabolomics and its association with altered oral redox homeostasis among youth

The use of alternative tobacco products, particularly medwakh, has expanded among youth in the Middle East and around the world. The present study is conducted to investigate the biochemical and pathophysiological changes caused by medwakh smoking, and to examine the salivary metabolomics profile of medwakh smokers. Saliva samples were collected from 30 non-smokers and 30 medwakh smokers and subjected to metabolomic analysis by UHPLC-ESI-QTOF-MS. The CRP and Glutathione Peroxidase 1 activity levels in the study samples were quantified by ELISA and the total antioxidant capacity (TAC) by TAC assay kits. Statistical measurements and thorough validation of data obtained from untargeted metabolomics identified 37 uniquely and differentially abundant metabolites in saliva of medwakh smokers. The levels of phthalate, L-sorbose, cytosine, uridine, alpha-hydroxy hippurate, and L-nicotine were noticeably high in medwakh smokers. Likewise, 20 metabolic pathways were differentially altered in medwakh smokers. This study identified a distinctive saliva metabolomics profile in medwakh smokers associated with altered redox homeostasis, metabolic pathways, antioxidant system, and CRP levels. The impact of the altered metabolites in medwakh smokers and their diagnostic utility require further research in large cohorts.

Myocardial infarction and oxidative damage in animal models: objective and expectations from the application of cysteine derivatives

Reactive oxygen species (ROS) and associated oxidative stress are the main contributors to pathophysiological changes following myocardial infarction (MI), which is the principal cause of death from cardiovascular disease. The glutathione (GSH)/glutathione peroxidase (GPx) system appears to be the main and most active cardiac antioxidant mechanism. Hence, enhancement of the myocardial GSH system might have protective effects in the setting of MI. It follows that by increasing antioxidant capacity, the heart will be able to reduce the damage associated with MI and even prevent/weaken the occurrence of oxidative stress, which is highly ranked among the factors responsible for the occurrence of acute MI. For these reasons, the primary goal of future investigations should be to address the effects of different antioxidative compounds and especially cysteine derivatives like N-acetyl cysteine (NAC) and L-2-oxothiazolidine-4-carboxylic acid (OTC) as precursors responsible for the enhancement of the GSH-related antioxidant system's capacity. It is assumed that this will lay down the basis for elucidation of the mechanisms throughout which applicable doses of OTC will manifest a potentially positive impact in the reduction of adverse effects of acute MI. The inclusion of OTC in the models for prediction of the distribution of oxygen in infarcted animal hearts can help to upgrade existing computational models. Such a model would be based on computational geometries of the heart, but the inclusion of biochemical redox features in addition to angiogenic therapy, despite improvement of the post-infarcted oxygenated outcome could enhance the accuracy of the predictive values of oxygenation.

Protective Effects of L-2-Oxothiazolidine-4-Carboxylate during Isoproterenol-Induced Myocardial Infarction in Rats: In Vivo Study

This study aimed to evaluate the cardioprotective effects of L-2-oxothiazolidine-4-carboxylate (OTC) against isoproterenol (ISO)-induced acute myocardial infarction (MI) in rats. Results demonstrated that OTC treatments inhibited ISO-induced oxidative damage, suppressed lipid peroxidation, and increased superoxide dismutase and catalase activity in the hearts of the treated rats compared to those of the untreated controls. The ISO-related NF-κB activation was reduced due to the OTC treatment, and lower degrees of inflammatory cell infiltration and necrosis in the hearts were observed. In summary, OTC treatments exerted cardioprotective effects against MI in vivo, mainly due to enhancing cardiac antioxidant activity.

Induction of P-glycoprotein expression by dandelion in tumor and heart tissues: Impact on the anti-tumor activity and cardiotoxicity of doxorubicin

BACKGROUND

Previously, we have investigated the anti-tumor activity and mechanism through which dandelion acts against triple-negative breast cancer (TNBC). However, traditional Chinese medicine is mostly accepted as an adjunct therapy during chemotherapy in clinical practice. So far, little is known about the effects of dandelion in conjunction with chemotherapeutic drugs.

PURPOSE

To investigate the effects of dandelion on the anti-tumor activity and cardiotoxicity of doxorubicin (DOX), and to further explore the molecular mechanisms through which these effects occur.

STUDY DESIGN

At the beginning of this study, dandelion was observed to alleviate DOX-induced cardiotoxicity and reduce the anti-tumor activity of DOX. Subsequently, we investigated whether the resistance to DOX mediated by P-glycoprotein was involved in the above effects.

METHODS

The cardioprotective effect of dandelion was investigated on DOX-treated mice by histological analysis, myocardial enzyme assays, and an untargeted metabolomics study based on LC-Q-TOF/MS. TNBC cell lines and 4T1 tumor-bearing mice were employed to investigate the combined anti-tumor activity. Laser scanning confocal microscope and a flow cytometry analysis were employed to measure the intracellular accumulation of DOX. A specific, sensitive, and rapid LC-MS/MS method was developed to detect the efflux of DOX from cells. Expression of P-glycoprotein in mouse tumor and heart tissues was detected via Western blotting analysis.

RESULTS

Dandelion was found to significantly alleviate DOX-induced cardiotoxicity, as was evidenced by improved cardiomyocyte morphology, decreased LDH and CK-MB release, and adjusted metabolic biomarker levels. However, in vitro and in vivo studies showed that dandelion could reduce the anti-tumor activity of DOX. This counteraction was achieved by activating of the drug efflux transporter P-glycoprotein, thereby promoting the efflux of DOX from cells and reducing the intracellular accumulation of DOX. Moreover, the activation of P-glycoprotein by dandelion in mouse heart tissue was also observed, thus suggesting that the decrease of cardiac DOX accumulation plays an important role in the cardioprotective effect of dandelion.

CONCLUSION

Dandelion can activate the P-glycoprotein in heart and tumor tissues, which ameliorates DOX-induced cardiotoxicity but attenuates DOX cytotoxicity toward TNBC. Our findings have important implications for the correct clinical use of dandelion.

Perinatal Administration of C-Phycocyanin Protects Against Atherosclerosis in apoE-Deficient Mice by Modulating Cholesterol and Trimethylamine-N-Oxide Metabolisms

OBJECTIVE

Gestational hypercholesterolemia concomitantly with a highly oxidative environment is associated with higher atherosclerosis in human and animal offspring. This work aimed to determine whether perinatal administration of a C-phycocyanin concentrate, a powerful antioxidant, can protect against atherosclerosis development in genetically hypercholesterolemic mice in adult life. Approach and Results: C-Phycocyanin was administered during gestation solely or gestation and lactation to apolipoprotein E-deficient mice. Male and female offspring were studied until 25 weeks old. Progenies born to supplemented mothers displayed significantly less atherosclerotic root lesions than control group in all groups excepted in male supplemented during gestation and lactation. Female born to supplemented mothers had a greater gallbladder total bile acid pool, lower secondary hydrophobic bile acid levels such as lithocholic acid, associated with less plasma trimethylamine N-oxide at 16 weeks old compared with control mice. Regarding male born to C-Phycocyanin administrated mothers, they expressed a higher high-density lipoprotein cholesterol level, more soluble bile acids such as β-muricholic acids, and a decreased plasma trimethylamine at 16 weeks old. Liver reduced-to-oxidized glutathione ratio were increased and liver gene expression of superoxide dismutase and glutathione peroxidase were significantly decreased in male born to gestational supplemented mothers. No difference in the composition of cecal microbiota was found between groups, regardless of sex.

CONCLUSIONS

Our findings suggest a protective effect of perinatal antioxidant administration on atherosclerosis development in apolipoprotein E-deficient mice involving sex-specific mechanisms.

Development and application of sequential window acquisition of all theoretical mass spectra data acquisition modes on ultra-high-performance liquid chromatography triple-quadrupole/time-of-flight mass spectrometry for metabolic profiling of amino acids in human plasma

Accumulating evidence suggests that amino acids are important indicators of nutritional and metabolic status. A high-resolution mass spectrometry method based on sequential window acquisition of all theoretical mass spectra acquisition was developed for the simultaneous determination of 16 amino acids in human plasma. Sample preparation by protein precipitation using a mixture of acetonitrile and formic acid was followed by a BEH Amide column. The superiority of this method was investigated by comparing it to time-of-flight scan and multiple reaction monitoring modes. The limit of detection in sequential window acquisition of all theoretical mass spectra mode for threonine, methionine, histidine, citrulline, and tryptophan is 0.1 ng on the column; for lysine and asparagine is 0.2 ng; for alanine, pyroglutamic acid, leucine, ornithine, and aspartate is 0.5 ng, for arginine is 1.0 ng; for glutamate and serine is 2.0 ng; for glutamine is 10.0 ng. This method was linear in the range 0.8-40 μg/mL for arginine, citrulline, glutamate, histidine, leucine, methionine, pyroglutamic acid, threonine, tryptophan; 2-100 μg/mL for asparagine, aspartate, lysine, ornithine, serine; and 4-200 μg/mL for alanine, glutamine with good accuracy and precision. Significantly different levels in 11 amino acids were observed between childhood and adulthood, representing the growth and development of individuals relating to the level of amino acids.

GC/MS and LC/MS Based Serum Metabolomic Analysis of Dairy Cows With Ovarian Inactivity

Metabolic disorders may lead to the inactive ovaries of dairy cows during early lactation. However, the detailed metabolic profile of dairy cows with inactive ovaries around 55 days postpartum has not been clearly elucidated. The objective of this study was to investigate the metabolic difference in cows with inactive ovaries and estrus from the perspective of serum metabolites. According to clinical manifestations, B-ultrasound scan, rectal examination, 15 cows were assigned to the estrus group (E; follicular diameter 15–20 mm) and 15 to the inactive ovary group (IO; follicular diameter <8 mm and increased <2 mm within 5 days over two examinations). The blood was collected from the tail vein of the cow to separate serum 55–60 days postpartum, and then milked and fasted in the morning. Serum samples were analyzed using gas chromatography time-of-flight mass spectrometry technology (GC-TOF-MS) and ultra-high-pressure liquid chromatography-quadrupole-time-of-flight mass spectrometry (UHPLC-QTOF-MS). Differences in serum metabolites were identified using multivariate statistical analysis and univariate analysis. Thirty differentially abundant metabolites were identified between the two groups. In cows with inactive ovaries compared with cows in estrus, 20 serum metabolites were significantly higher (beta-cryptoxanthin (p = 0.0012), 9-cis-retinal (p = 0.0030), oxamic acid (p = 0.0321), etc.) while 10 metabolites were significantly lower (monostearin (p = 0.0001), 3-hydroxypropionic acid (p = 0.0005), D-talose (p = 0.0018), etc.). Pathway analysis indicated that the serum differential metabolites of multiparous cows in estrus obtained by the two metabolomics techniques were mainly involved in β-alanine metabolism and steroid biosynthesis metabolism, while other involved metabolic pathways were related to metabolism of glyoxylate; dicarboxylate metabolism; fructose, mannose, glutathione, glycerolipid, glycine, serine, threonine, propanoate, retinol, and pyrimidine metabolism. This indicates that the abnormalities in glucose metabolism, lipid metabolism, amino acid metabolism, and glutathione metabolism of postpartum dairy cows obstructed follicular development.

The cardioprotective effects of the new crystal form of puerarin in isoproterenol-induced myocardial ischemia rats based on metabolomics

Puerarin has shown unique pharmacological effects on myocardial ischemia (MI). Changing the crystal form is an effective approach to improve the cardioprotective effects of puerarin. However, the mechanisms of the new crystal form of puerarin are unclear. In this study, an electrocardiogram, echocardiography, cardiac marker enzymatic activity, oxidative stress indices, and myocardial histology analysis of cardiac tissues were performed to evaluate the cardioprotective effects of the new crystal form of puerarin. Moreover, serum and cardiac tissue metabolomics based on nuclear magnetic resonance (NMR) were used to investigate the potential mechanism of the new crystal form. The results indicated that the new crystal form of puerarin (30 mg/kg) could improve oxidative stress indices, and these improvements were similar to those of the original crystal form of puerarin (120 mg/kg). The new crystal form of puerarin (30 mg/kg) could effectively improve the activities of cardiac marker enzymes, and the improvement effects were better than those of the original crystal form (120 mg/kg). Moreover, metabolomics analysis showed that amino acid metabolism, oxidative stress and energy metabolism were disturbed after MI and could be improved by puerarin. These results demonstrated that the new crystal form of puerarin was effective in treating MI.

Exploring the protective effects of Danqi Tongmai tablet on acute myocardial ischemia rats by comprehensive metabolomics profiling

BACKGROUND

Danqi Tongmai tablet (DQTM), a combination of salvianolic acids (SA) and panax notoginsenosides (PNS), is now in phase II clinical trial developed for the treatment of cardiovascular diseases. However, the mechanisms of its protective effects through regulating endogenous metabolites remain unclear.

PURPOSE

The purpose of this study was to explore the protective effects of DQTM on acute myocardial ischemia rats by comprehensive metabolomics profiling.

STUDY DESIGN

The rats were divided into three groups: sham-operating, acute myocardial ischemia (AMI) and DQTM groups. The plasma and heart were collected and profiled by LC-MS based metabolomics and lipidomics. Based on the identified differential metabolites, the pathway analysis results were obtained and further validated using the network pharmacology approach.

METHODS

The AMI model was induced by ligating the left anterior descending coronary artery. The metabolomics and lipidomics profiling were based on two established LC-QTOF/MS analysis methods. The raw data were processed using XCMS Online, then the differential metabolites with nonparametric t-test p value less than 0.05 were selected and identified using HMDB and METLIN. The pathway analysis was conducted using MetaboAnalyst and validated with the predicted network results obtained by BATMAN-TCM.

RESULTS

The metabolomics and lipidomics profiles of plasma and heart in response to AMI and DQTM were significantly different. The AMI operation had a serious influence on metabolites in heart ischemia region, while DQTM had a greater impact on lipids in heart non-ischemia region. A total of 151 differential metabolites were identified, including mainly amino acids and fatty acids. Multiple metabolic pathways were disturbed after AMI and could be restored by DQTM, of which arachidonic acid metabolism was further validated with the predicted results of network pharmacology.

CONCLUSION

The protective effects of DQTM on acute myocardial ischemia rats could be achieved through the regulation of multiple metabolic pathways.

Development and validation of a rapid, robust and sensitive UPLC-QQQ-MS/MS method for simultaneous quantification of GSH metabolism in lung cancer cells

Changes in cellular metabolism accompany tumor therapeutic resistance. Metabolite concentrations specifically reflect the cellular state. Glutathione (GSH) metabolism maintains the redox homeostasis while also confers therapeutic resistance to cancer cells. However, analytical methods for studying GSH metabolism rely on high-resolution-based untargeted metabolomics. Since the aim of untargeted metabolomics studies is covering as much metabolites as possible, these methods lack sensitivity for simultaneous analysis of intracellular GSH-related metabolites with different polarities and structures. In this study, based on cultured lung cancer cells, we described a rapid, robust and sensitive ultra-performance liquid chromatography-triple quadrupole tandem mass spectrographic method (UPLC-QQQ-MS/MS) to simultaneously quantify a repertoire of GSH-related metabolites, including GSH, GSSG, glycine, cysteine, glutamine, glutamate, cystine, γ-glutamyl-cysteine and cysteinyl-glycine. This method avoided the use of derivatization and/or ion-pairing reagents and was validated according to United States Food and Drug Administration (US FDA) criteria. The lower limit of quantification was determined to be 0.5-100 ng/mL with lower limits of detection at 0.14-10.07 ng/mL. The intra- and inter-day precision values for all the analytes were <15% CV, and the accuracy ranged from 85.4% to 114% at three levels of quality control. This method combined simple preparation with rapid analytical procedure (8 min), allowed for high-throughput analysis of GSH metabolism in basic and therapeutic treatment conditions within cultured cells. Our data showed a significant alteration of GSH metabolism in two independent resistant cells compared to sensitive cells. This method monitored the impact of molecularly targeted drugs on GSH metabolism within lung cancer cells and therefore helped identifying potential metabolic vulnerability for the therapeutic resistance in lung cancer.

Metal coordination-functionalized Au–Ag bimetal SERS nanoprobe for sensitive detection of glutathione

Neocuproine-Cu functionalized Au–Ag nanoparticles as nanoprobe for detection of glutathione based on the SERS spectra changing from Neocuproine-Cu^II to Neocuproine-Cu^I.