Variable Importance In Projection Scores Research Articles

Transfer of Exercise-Microbiome Is Suffcient to Induce a Shift in the Skeletal Muscle Metabolomic Profile without an Exercise Stimulus

Introduction: Skeletal muscle is a tissue that dynamically responds to disuse, which can induce rapid loss of mass and function. Identification of novel drug candidates will facilitate the development of supportive therapies for extended periods of decreased mobility, both planned and unanticipated. Recent findings from our lab as well as others indicate the important role of the gut microbiome in mediating the beneficial effects of exercise. Hypothesis: Transfer of microbiome from excise-trained mice into exercise-naïve mice will induce metabolic adaptations in the recipient skeletal muscle. Method: Sedentary and exercise-trained mice were used as donors for microbiome transfer. Exercise training consisted of 8-weeks of processive weighted wheel running. Exercise-naïve recipient mice were bowel cleansed with polyethylene glycol and transplanted with either sedentary (SED) or exercise-trained (EXER) donor microbiome. Recipient cecal content, serum, and gastrocnemius muscle were collected for untargeted metabolomics using liquid chromatography mass spectrometry. Results: Partial Least Squares Discriminant Analysis indicated significant metabolic discrimination between EXER and SED in all samples (cecal, serum, and muscle). Variable Importance in Projection scores identified several metabolites as significant discriminating metabolic features between EXER and SED, including ones involved in the TCA cycle, lysine and fatty acid degradation pathways. Conclusion: Transfer of microbial content from exercise-trained mice is suffcient to induce changes in muscle metabolite profile reminiscent of exercise in the absence of such a stimulus. Funding: This work is supported by the National Institute on Aging (AG071888). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

An integrated metabo-lipidomics profile of induced sputum for the identification of novel biomarkers in the differential diagnosis of asthma and COPD

BackgroundDue to their complexity and to the presence of common clinical features, differentiation between asthma and chronic obstructive pulmonary disease (COPD) can be a challenging task, complicated in such cases also by asthma–COPD overlap syndrome. The distinct immune/inflammatory and structural substrates of COPD and asthma are responsible for significant differences in the responses to standard pharmacologic treatments. Therefore, an accurate diagnosis is of central relevance to assure the appropriate therapeutic intervention in order to achieve safe and effective patient care. Induced sputum (IS) accurately mirrors inflammation in the airways, providing a more direct picture of lung cell metabolism in comparison to those specimen that reflect analytes in the systemic circulation.MethodsAn integrated untargeted metabolomics and lipidomics analysis was performed in IS of asthmatic (n = 15) and COPD (n = 22) patients based on Ultra-High-Pressure Liquid Chromatography-Mass Spectrometry (UHPLC-MS) and UHPLC–tandem MS (UHPLC-MS/MS). Partial Least Squares-Discriminant Analysis (PLS-DA) was applied to resulting dataset. The analysis of main enriched metabolic pathways and the association of the preliminary metabolites/lipids pattern identified to clinical parameters of asthma/COPD differentiation were explored. Multivariate ROC analysis was performed in order to determine the discriminatory power and the reliability of the putative biomarkers for diagnosis between COPD and asthma.ResultsPLS-DA indicated a clear separation between COPD and asthmatic patients. Among the 15 selected candidate biomarkers based on Variable Importance in Projection scores, putrescine showed the highest score. A differential IS bio-signature of 22 metabolites and lipids was found, which showed statistically significant variations between asthma and COPD. Of these 22 compounds, 18 were decreased and 4 increased in COPD compared to asthmatic patients. The IS levels of Phosphatidylethanolamine (PE) (34:1), Phosphatidylglycerol (PG) (18:1;18:2) and spermine were significantly higher in asthmatic subjects compared to COPD.ConclusionsThis is the first pilot study to analyse the IS metabolomics/lipidomics signatures relevant in discriminating asthma vs COPD. The role of polyamines, of 6-Hydroxykynurenic acid and of d-rhamnose as well as of other important players related to the alteration of glycerophospholipid, aminoacid/biotin and energy metabolism provided the construction of a diagnostic model that, if validated on a larger prospective cohort, might be used to rapidly and accurately discriminate asthma from COPD.Graphical

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.

Effects of pretreated garlic on bacterial composition and metabolite profiles during kimchi fermentation

This study investigated the effects of pretreated garlic on the fermentation characteristics of kimchi; four types of kimchi using pretreated garlic [raw (RGK), frozen (FGK), blanched (BGK), and blanched-frozen (BFGK)] were prepared; fermentation was carried out at 4 °C for 6 weeks. The fermentation properties, microbial community composition, metabolic compounds, and volatile organic compounds (VOC) were investigated. The total viable bacterial count in blanched garlic was reduced significantly compared to those in raw and frozen garlic. Latilactobacillus spp. became the dominant species in all kimchi samples as the fermentation progressed. Of the 145 metabolites observed by gas chromatography and mass spectrometry, 51 volatile metabolites were observed. Glucose, fructose, sucrose, lactic acid, citric acid, and mannitol were present as major metabolites (variable importance in projection scores >1.0). Frozen garlic (FGK and BFGK) reduced the production of sulfuric VOC compounds, while raw garlic increased the production of these compounds, specifically that of allyl methyl sulfide, dimethyl disulfide, and dimethyl trisulfide. In conclusion, the condition of garlic added to kimchi affects the abundance of microorganisms during initial fermentation and the quality characteristics of kimchi during the fermentation period. These results help establish garlic pretreatment conditions for kimchi manufacturing.

A Metabolomic Analysis to Assess the Responses of the Male Gonads of Mytilus galloprovincialis after Heavy Metal Exposure.

In recent years, metabolomics has become a valuable new resource in environmental monitoring programs based on the use of bio-indicators such as Mytilus galloprovincialis. The reproductive system is extremely susceptible to the effects of environmental pollutants, and in a previous paper, we showed metabolomic alterations in mussel spermatozoa exposed to metal chlorides of copper, nickel, and cadmium, and the mixture with these metals. In order to obtain a better overview, in the present work, we evaluated the metabolic changes in the male gonad under the same experimental conditions used in the previous work, using a metabolomic approach based on GC-MS analysis. A total of 248 endogenous metabolites were identified in the male gonads of mussels. Statistical analyses of the data, including partial least squares discriminant analysis, enabled the identification of key metabolites through the use of variable importance in projection scores. Furthermore, a metabolite enrichment analysis revealed complex and significant interactions within different metabolic pathways and between different metabolites. Particularly significant were the results on pyruvate metabolism, glycolysis, and gluconeogenesis, and glyoxylate and dicarboxylate metabolism, which highlighted the complex and interconnected nature of these biochemical processes in mussel gonads. Overall, these results add new information to the understanding of how certain pollutants may affect specific physiological functions of mussel gonads.

Detection of carbon nanotubes in bovine raw milk through Fourier transform Raman spectroscopy

The potential use of carbon-based methodologies for drug delivery and reproductive biology in cows raises concerns about residues in milk and food safety. This study aimed to assess the potential of Fourier transform Raman spectroscopy and discriminant analysis using partial least squares (PLS-DA) to detect functionalized multiwalled carbon nanotubes (MWCNT) in bovine raw milk. Oxidized MWCNT were diluted in milk at different concentrations from 25.00 to 0.01 µg/mL. Raman spectroscopy measurements and PLS-DA were performed to identify low concentrations of MWCNT in milk samples. The PLS-DA model was characterized by the analysis of the variable importance in projection (VIP) scores. All the training samples were correctly classified by the model, resulting in no false-positive or false-negative classifications. For test samples, only one false-negative result was observed, for 0.01 µg/mL MWCNT dilution. The association between Raman spectroscopy and PLS-DA was able to identify MWCNT diluted in milk samples up to 0.1 µg/mL. The PLS-DA model was built and validated using a set of test samples and spectrally interpreted based on the highest VIP scores. This allowed the identification of the vibrational modes associated with the D and G bands of MWCNT, as well as the milk bands, which were the most important variables in this analysis.

Virtual diagnosis of diabetic nephropathy using metabolomics in place of kidney biopsy: The DIAMOND study

AimsTo explore the clinical factors and urinary metabolites that predict biopsy-confirmed diabetic nephropathy (DN) in patients with type 2 diabetes mellitus (T2DM). MethodsData from the medical records of 126 patients with T2DM who underwent kidney biopsy between January 2010 and October 2020 at a single-center were retrospectively reviewed to investigate the clinical factors that predict DN. Urine samples were collected to perform urine metabolomics in patients with T2DM divided by biopsy-confirmed DN, immunoglobulin A, and membranous nephropathy, and a control group of healthy participants. Each group comprised 11 age- and sex-matched participants. A prediction model was developed using a combination of clinical factors and urinary metabolites, and a multivariate receiver operating characteristic (ROC) analysis was conducted. ResultsAge, presence of proliferative diabetic retinopathy, T2DM duration, and hemoglobin A1c levels were clinical factors predictive of DN. Four urinary metabolites (alanine, choline, N-phenylacetylglycine, and trigonelline) had variable importance in projection scores > 1 and were predictive of DN. When conducting multivariate ROC analysis with a combination of clinical factors and urinary metabolites, the area under the curve was 1.000. ConclusionsThe combination of clinical factors and urinary metabolites is highly valuable for predicting biopsy-confirmed DN in patients with T2DM.

Identification of potential quality markers in Indonesia’s Arabica specialty coffee using GC/MS-based metabolomics approach

IntroductionThe cupping test is a widely used method for quality assessment of Arabica coffee. However, the cupping test is limited by the low number of certified panelists and the low throughput. Therefore, an analytical-based quality assessment may be a promising tool to complement the cupping test. A present, there is no report investigating quality marker candidates, focusing only on “specialty” grade Arabica coffee from Indonesia.ObjectiveThis study identified the potential quality marker(s) in Arabica Specialty coffee at different stages (green beans, roasted beans, and brewed coffee.MethodsThe metabolite profiles of ten different Arabica specialty-grade coffees were analyzed with different cup scores using gas chromatography–mass spectrometry (GC/MS). From the ten samples, green coffee beans, roasted coffee beans, and brewed coffee were selected. In addition, an orthogonal projection to latent structure (OPLS) regression analysis was conducted to obtain a potential quality marker based on the variable importance in projection (VIP). The potential quality marker(s) were validated by GC/MS metabolome profiling and OPLS analysis of different sets of samples consisting of 35 Arabica specialty-grade coffee samples.ResultsIn Arabica coffee samples, the OPLS model of the three stages showed galactinol to have a high VIP score. Galactinol showed a consistent positive correlation with cup scores at all stages of coffee production (green beans, roasted beans, and brewed coffee). The correlation suggests galactinol is a potential quality marker after further validation using different samples.ConclusionGC/MS combined with OPLS regression analysis suggested galactinol as a quality marker and provide an early screening method for Arabica coffee quality that complements the cupping test performed by certified panelists.

Seminal plasma untargeted metabolomic and lipidomic profiling for the identification of a novel panel of biomarkers and therapeutic targets related to male infertility.

Male infertility occurs approximately in about 50% of all infertility cases and represents a serious concern worldwide. Traditional semen analysis alone is insufficient to diagnose male infertility. Over the past two decades, advances in omics technologies have led to the widespread application of metabolomics profiling as a valuable diagnostic tool for various diseases and disorders. Seminal plasma represents a rich and easily accessible source of metabolites surrounding spermatozoa, a milieu that provides several indispensable nutrients to sustain sperm motility and fertilization. Changes of metabolic profiles in seminal plasma reflect male reproductive tract disorders. Here, we performed seminal plasma metabolomics and lipidomics profiling to identify a new pattern of biomarkers of male infertility. Seminal plasma samples from unfertile subjects (n = 31) and fertile controls (n = 19) were analyzed using an untargeted metabolomics/lipidomics integrated approach, based on Ultra-High-Pressure Liquid Chromatography-tandem Mass Spectrometry. Partial Least Squares-Discriminant Analysis showed a distinct separation between healthy fertile men and infertile subjects. Among the 15 selected candidate biomarkers based on Variable Importance in Projection scores, phosphatidylethanolamine (PE) (18:1; 18:1) resulted with the highest score. In total, 40 molecular species showed statistically significant variations between fertile and infertile men. Heat-map and volcano plot analysis indicated that acylcarnitines, phosphatidylserine (PS) (40:2) and lactate were decreased, while PE (18:1; 18:1), Phosphatidic acid (PA) (O-19:2; 18:1), Lysophosphatidylethanolamine (LPE) (O-16:1) and Phosphatidylcholine (PC) (O-16:2; 18:1)-CH3 were increased in the infertile group. The present study is the first one to analyze the metabolomics/lipidomics dysregulation in seminal plasma between fertile and infertile individuals regardless of sub-infertility condition. Association of several metabolites/lipids dysregulation with male infertility reinforced data of previous studies performed with different approaches. In particular, we confirmed significantly decreased levels of PS and carnitines in infertile patients as well as the positive correlation with sperm motility and morphology. If validated on a larger prospective cohort, the metabolite biomarkers of infertility in seminal plasma we identified in the present study might inform novel strategies for diagnosis and interventions to overcome male infertility.

Associations of High-Density Lipoprotein Functionality with Coronary Plaque Characteristics in Diabetic Patients with Coronary Artery Disease: Integrated Backscatter Intravascular Ultrasound Analysis.

High-density lipoprotein (HDL) functionality has been reported to be associated with coronary artery disease (CAD). However, little is known about the impact of HDL functionality on coronary atherosclerosis. Thirty-eight type 2 diabetic patients with CAD who underwent percutaneous coronary intervention were examined. Coronary atheroma burden and plaque composition of the culprit lesions were assessed using conventional gray-scale and integrated backscatter intravascular ultrasound. HDL-mediated cholesterol efflux capacity (HDL-CEC) and HDL antioxidant capacity, estimated as HDL inflammatory index (HII), were examined. The associations between HDL functionality and coronary plaques were analyzed using multivariate data analysis, including principal components analysis and orthogonal partial least squares (OPLS) models. Percent atheroma volume was correlated with HDL-CEC (r = 0.34, p = 0.04) but not with HII (p = 0.65). The OPLS model demonstrated that the percentage lipid volume was significantly associated with HDL functionality [coefficient (95% confidence interval); HDL-CEC: -0.26 (-0.49, -0.04); HII: 0.34 (0.08, 2.60), respectively]. HII exhibited the highest variable importance in projection score, indicating the greatest contribution. HDL functionality was associated with coronary plaque composition, a key component of plaque vulnerability. Our findings highlight the potential importance of HDL functionality for coronary plaque stabilization.

Discovery of candidate biomarkers to discriminate between Korean and Japanese red seabream (Pagrus major) using metabolomics

Red seabream (Pagrus major) is widely consumed in East Asia. As nuclear wastewater is discharged into Japanese waterbodies, the country of origin of marine products must be accurately labeled. Here, we aimed to discover candidate metabolite biomarkers to discriminate between Korean and Japanese red seabream using LC-Orbitrap mass spectrometry. In total, 95 and 138 putative metabolites were detected via chromatographic separation of fish sampled in the warm and cold seasons, respectively. The spectrometric and chromatographic data were analyzed using principal component analysis and orthogonal partial least squares discriminant analysis. We identified 12 and 19 influential metabolites to discriminate between each origin fish in the warm and cold seasons, respectively, using variable importance in projection scores and p values. Anserine was further selected as a candidate biomarker based on receiver operating characteristic curve analysis. This study provides a basis for using anserine to determine the geographic origin of red seabream.

Electronic tongue for the simple and rapid determination of taste and odor compounds in water

Taste and odor (T&O) compounds present in natural water bodies could originate from algae. In this study, alga-generated compounds that can cause T&O issues in water, such as geosmin (GE), 2-Methylisoborneol (MIB), 2,4,6-Trichloroanisole (TCA), 2-Methylbenzofuran (MB), 2-Isopropyl-3-methoxypyrazine (IPMP), 2-Isobutyl-3-methoxypyrazine (IBMP), cis-3-Hexenyl acetate (HA), trans,trans-2,4-Heptadienal (HD), trans,cis-2,6-Nonadienal (ND), and trans-2-Decenal (DN), were determined through solid-phase microextraction coupled with gas chromatography/mass spectrometry (HS-SPME GC/MS) and electronic tongue (E-tongue), and the results from the two techniques were compared. Although HS-SPME GC/MS facilitates the detection and quantification of T&O compounds with high precision and accuracy, the sample preparation and handling is difficult and the analysis time (1 h) is longer than those of other analytical methods. E-tongue can be used as an alternative analytical method for water quality analysis and risk management because it enables controlled and rapid analysis (3 min) of T&O compounds in water at a low cost. Notably, principal component analysis indicated that E-tongue can discriminate and quantify eight T&O compounds at as low as 0.02 μg L−1 concentration. Further, partial least squares analysis confirmed that the sensor exhibits high sensitivity to concentration changes. The sensors with the highest variable importance in projection scores were determined to be SCS (1.39 and 1.38) for GE and MIB, CTS (1.34) for IPMP, CPS (1.33) for IBMP, AHS (1.42) for HA, ANS (1.22) for HD, and NMS (1.14 and 1.19) for ND and DN.

Metabolic changes in the plasma of mild Alzheimer's disease patients treated with Hachimijiogan.

Background: Alzheimer's disease (AD), the most prevalent form of dementia, is a debilitating, progressive neurodegeneration. Amino acids play a wide variety of physiological and pathophysiological roles in the nervous system, and their levels and disorders related to their synthesis have been related to cognitive impairment, the core feature of AD. Our previous multicenter trial showed that hachimijiogan (HJG), a traditional Japanese herbal medicine (Kampo), has an adjuvant effect for Acetylcholine estelase inhibitors (AChEIs) and that it delays the deterioration of the cognitive dysfunction of female patients with mild AD. However, there are aspects of the molecular mechanism(s) by which HJG improves cognitive dysfunction that remain unclear. Objectives: To elucidate through metabolomic analysis the mechanism(s) of HJG for mild AD based on changes in plasma metabolites. Methods: Sixty-seven patients with mild AD were randomly assigned to either an HJG group taking HJG extract 7.5g/day in addition to AChEI or to a control group treated only with AChEI (HJG:33, Control:34). Blood samples were collected before, 3months, and 6months after the first drug administration. Comprehensive metabolomic analyses of plasma samples were done by optimized LC-MS/MS and GC-MS/MS methods. The web-based software MetaboAnalyst 5.0 was used for partial least square-discriminant analysis (PLS-DA) to visualize and compare the dynamics of changes in the concentrations of the identified metabolites. Results: The VIP (Variable Importance in Projection) score of the PLS-DA analysis of female participants revealed a significantly higher increase in plasma metabolite levels after HJG administration for 6months than was seen in the control group. In univariate analysis, the aspartic acid level of female participants showed a significantly higher increase from baseline after HJG administration for 6months when compared with the control group. Conclusion: Aspartic acid was a major contributor to the difference between the female HJG and control group participants of this study. Several metabolites were shown to be related to the mechanism of HJG effectiveness for mild AD.

Chemical Structural Features Affecting the Soil Sorption of Sulfonylurea Herbicides

ABSTRACT The contamination of groundwater by herbicides depends on their mobility in soil, which is related to the organic carbon to water partition coefficient, KOC. Because the log KOC values of widely used sulfonylurea herbicides do not correlate with easily accessible log P estimations, multivariate image analysis (MIA) descriptors were employed to build structure-property models to classify these compounds according to their soil sorption capability. In addition, a deeper analysis based on MIA contour maps of PLS regression coefficients and variable importance in projection scores was performed to obtain insight into the chemical features responsible for the log KOC behavior. A multiple linear regression model obtained from selected descriptors demonstrated high predictability (r2 = 0.95, q2 = 0.84, and r2 pred = 0.71) and also provided chemical insight into the log KOC values. It has been found that triazine rather than pyrimidine derivatives are less prone to leach out, but substituents attached to the sulfonyl group play an important role in modulating the log KOC values. Consequently, useful guidance for environmental risk assessment is provided for the development of new sulfonylurea herbicides.

Study of two combined series of triketones with HPPD inhibitory activity by molecular modelling

ABSTRACT Triketones are suitable compounds for 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibition and are important compounds for eliminating agricultural weeds. We report herein quantitative structure-activity relationship (QSAR) modelling and docking studies for a series of triketone-quinoline hybrids and 2-(aryloxyacetyl)cyclohexane-1,3-diones with the aim of proposing new chemical candidates that exhibit improved performance as herbicides. The QSAR models obtained were reliable and predictive (average r 2, q 2, and r 2 pred of 0.72, 0.51, and 0.71, respectively). Guided by multivariate image analysis of the PLS regression coefficients and variable importance in projection scores, the substituent effects could be analysed, and a promising derivative with R1 = H, R2 = CN, and R3 = 5,7,8-triCl at the triketone-quinoline scaffold (P18) was proposed. Docking studies demonstrated that π–π stacking interactions and specific interactions between the substituents and amino acid residues in the binding site of the Arabidopsis thaliana HPPD (AtHPPD) enzyme support the desired bioactivity. In addition, compared to a benchmark commercial triketone (mesotrione), the proposed compounds are more lipophilic and less mobile in soil rich in organic matter and are less prone to contaminate groundwater.

The increasing contribution of greening to the terrestrial evapotranspiration in China

Evapotranspiration (ET) in terrestrial ecosystems is of great significance for water resource evaluation, crop water requirements, and drought monitoring and is affected by multiple environmental factors. Several studies investigated the environmental factors affecting evapotranspiration with long time series, but there are few detailed research exploring changes in the dominant controls of ET. It is essential to understand the primary mechanisms involved and their response to climate change. In this study, we analyzed the dominant controls on ET using variable importance in projection (VIP) scores from a Partial Least Squares Regression (PLSR) analysis and then explored the change of dominant controls over time. Our results indicated a significant ET increase trend over 1982–2015 of 1.40 mm/year in China, with solar radiation (SR), temperature (T), and leaf area index (LAI), as the dominant controls contributing to the increasing changes of ET. Increase in LAI (greening) was the primary cause of increasing ET over the 1982–2015 period, especially in temperate monsoon climate regions. In contrast, the VIP scores of SR and T indicated a negative contribution to increasing ET during the 34 years. The differences in the contribution dynamics of dominant controls to ET may result from different sensitivities to canopy resistance in different vegetation types. This research revealed an increasing contribution of greening to terrestrial evapotranspiration in China and improved our understanding of the change of dominant controls over China from 1982 to 2015 and their influence to ET under the changing climate and its impact.

Using HRMS fingerprinting to explore micropollutant contamination in soil and vegetables caused by swine wastewater irrigation

Livestock wastewater has been reused for agricultural irrigation to save water and fertilise the soil. However, micropollutants excreted by livestock animals may contaminate the soil and crops through livestock wastewater irrigation. This study employed high-resolution mass spectrometry (HRMS) to facilitate broad-scope suspect screening of soil and vegetables and identify changes in micropollutant fingerprints caused by swine wastewater irrigation.Field trials were performed to simulate the practical cultivation of small leafy vegetables. Soil and pak choi were irrigated with groundwater, a reasonable amount of swine wastewater, and excessive swine wastewater (three times the reasonable amount) and were sampled at three time points. The samples were extracted using organic solvents and analysed with a liquid chromatography–quadrupole-time-of-flight HRMS system. The molecular features were compared to over 3000 micropollutants in commercial libraries. The relative concentrations of suspect micropollutants among the irrigation groups were compared using multivariate and univariate analyses. The marker micropollutants that increased with swine wastewater irrigation were rigorously identified based on the MS/MS spectra.Fifty-three micropollutants were frequently found in the soil (n = 54) and 36 in the pak choi (n = 53). Partial least squares discriminant analysis (PLS-DA) models revealed significant differences in the micropollutant fingerprints in the soil among the three irrigation groups, but not in the pak choi. Eight micropollutants with variable importance in projection scores above 1.0 in the PLS-DA model and significantly higher relative concentrations (p < 0.05) in the soil irrigated with swine wastewater were confirmed as markers. Besides veterinary drugs and their metabolites, cinnamic acid and phenylalanine were the markers relevant to swine feed that were not previously reported. Nevertheless, accumulations of micropollutants in the soil or contamination of the pak choi due to swine wastewater irrigation were not found under the trial conditions.

Urine metabolomic characteristics of female patients with occupational chronic cadmium poisoning after 15 years of treatment.

Occupational chronic cadmium poisoning (OCCP) can cause irreversible organ damage. Currently, no effective treatment is available for OCCP, and effective and sensitive biomarkers for treatment evaluation are still lacking. In this study, metabolomics techniques were used to analyze changes in endogenous metabolites in the urine of patients with OCCP after 15 years of treatment. Thirty urine samples from female patients with OCCP and healthy female controls (n = 15 per group) were assessed using gas chromatography-time-of-flight mass spectrometry and ultra-high-performance liquid chromatography-Q-Exactive mass spectrometry. The OCCP group had higher concentrations of blood urea nitrogen and urinary cadmium but near-normal urinary concentrations of β2 -microglobulin and retinol-binding protein. Compared with the control group, the OCCP group had 66 significantly different metabolites with a variable importance in projection score >1 and p < 0.05. These differential metabolites were involved in various metabolic pathways, such as creatine metabolism, nicotinate and nicotinamide metabolism, the pentose phosphate pathway, d-glutamine and d-glutamate metabolism, and amino acid metabolism. Compared with the control group, the OCCP group had significantly higher urinary concentrations of creatine, glutamic acid, quinolinic acid and nicotinic acid. In a receiver operator characteristic analysis, the area under the curve of creatine was higher than those for glutamic acid, quinolinic acid and nicotinic acid, indicating that urinary concentrations of creatine could be used as a sensitive biomarker for the diagnosis and prognosis of OCCP and for monitoring its treatment.

Targeted Metabolomics Approach Identifies Alterations in the Plasma Metabolome of Multiple Myeloma Patients with and without Extramedullary Spread

Introduction: Metabolomics refers to the identification and quantitation of metabolites in cells, tissues and biofluids. The metabolome (complete set of metabolites in a biological sample) reflects the biochemical events occurring in an organism at a given time, thus providing a valuable source to analyse metabolic changes in a variety of diseases, including cancer. Metabolic profiling of blood cancers represents a useful tool for the detection of novel biomarkers and therapeutic targets. Multiple myeloma (MM) accounts for less than 2% of all new cancer cases in the United States. The rare and aggressive sub-entity of MM, extramedullary multiple myeloma (EMM), develops when malignant plasma cells escape the bone marrow microenvironment and colonize distal tissues or organs. The prognosis of EMM is poor, and the incidence of EMM increases at disease progression, occurring in up to 30% of relapsed MM patients. The pathogenic mechanisms of EMM are poorly understood with no targeted therapies currently available to strategize treatment regimens. Here, we use a targeted metabolomics approach to identify metabolic changes in the plasma of MM patients with and without extramedullary spread. Methods: Targeted metabolomic analysis of age and gender-matched medullary MM (n=8) and EMM (n=9) blood plasma samples was performed using the MxP® Quant 500 kit (Biocrates Life Sciences AG, Innsbruck, Austria) with a SCIEX QTRAP 6500plus mass spectrometer. The MxP® Quant 500 kit is capable of quantifying more than 600 metabolites from 26 compound classes. Quality control (QC) samples were employed to monitor the performance of the analysis with metabolite concentration in each sample normalised based on these QC samples. Isotopically labelled internal standards and seven-point calibration curves were used in the quantitation of amino acids and biogenic amines. Semi-quantitative analysis of other metabolites was performed using internal standards. Data quality was evaluated by checking the accuracy and reproducibility of QC samples. Metabolites were included only when the concentrations of the metabolites were above the limit of detection (LOD) in >75% of plasma samples. Data was imported into MetaboAnalyst 5.0 for further analysis. Feature filtering was performed based on relative standard deviation (RSD) and the resulting data was autoscaled. Metabolites of interest were identified based on p-value < 0.01 and fold-change > 1.5 between experimental groups. Supervised statistical approaches were used to further interrogate the data. Results: Using a targeted metabolomic technique, we compared the metabolic profile of MM and EMM patient plasma. Univariate analysis using a t-test identified 5 metabolites of interest; HexCer(d18:1/20:0), TG(16:0_34:2), TG(22:4_32:0), TG(18:2_32:0), and Taurine (Figure 1(A)). The supervised clustering technique orthogonal projection to latent structure discriminant analysis (OPLS-DA) was used to determine separation between the two groups (MM and EMM). OPLS-DA scores plot illustrated a distinct separation between MM patients with extramedullary spread (red dots) compared to those without extramedullary spread (green dots) (Figure 1(B)). A permutation test (n=1000) was performed to ensure there was no overfitting of the data. Permutation analysis results (Q2 = 0.478, p = 0.023; R2Y = 0.978, p = 0.033) demonstrated the model was of good predictive quality. Discriminatory variables responsible for the group separation were identified using the OPLS-DA variable importance in projection (VIP) score to identify metabolites with a score greater than 1.5. HexCer(d18:1/20:0), TG(16:0_34:2), TG(22:4_32:0), TG(18:2_32:0), and Taurine had VIP scores of 2.5, 2.3, 2.1, 2.2 and 2.4, respectively. The diagnostic potential of these metabolites as EMM biomarkers was evaluated by receiver operating characteristic (ROC) curve analysis. All 5 metabolites demonstrated high diagnostic potential with area under the curve (AUC) values greater than 0.84. Conclusion: Investigating disease-associated metabolomes presents an opportunity to identify dysregulated metabolic processes and novel biomarkers. This pilot targeted metabolomic analysis of EMM plasma samples reveals metabolites of interest for further analysis and contributes to our understanding of EMM pathophysiology. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

RF22 | PMON10 Exposure to a Real Life Environmental Chemical Mixture Alters the Metabolite Profile in the Plasma of Sheep: An Untargeted Metabolomics Study.

Abstract Humans are exposed to a mixture of endocrine disrupting chemicals (EDCs) in everyday life, believed to contribute to a range of non-communicable diseases. While the adverse health impacts of exposure to individual EDCs have been extensively investigated, studies on effects of real-world exposures characterized by chronic low doses of a mixture of chemicals, are only recently emerging. Biosolids derived from human wastes, exemplify both the array and dosage of chemicals humans are exposed to in real life and represents a novel model to investigate the risk posed by the EDCs. Previous studies in sheep have demonstrated aberrant reproductive and metabolic phenotypic effects in offsprings, as a result of maternal biosolid exposure. We hypothesize that EDC-mediated disruption in the maternal metabolic milieu is a potential mediator of the aberrant phenotypic outcomes in offsprings in the biosolid-exposure model. Recent untargeted metabolomic studies provide evidence of the technique's ability to unravel biomarkers of both exposure and effect by identifying the disrupted endogenous metabolite profile and xenobiotic mixture, respectively. In this study, we sought to identify biosolid exposure-induced maternal metabolic fingerprints that could influence fetal programming. Ewes were grazed on either organic fertilizer or biosolid-treated pastures from 1 month before mating until close to parturition. Plasma from blood samples collected on day 90 of the 147-day gestation period, from ewes carrying singleton pregnancies (Control n=15, Treatment n=15) were subjected to untargeted metabolomics using liquid chromatography-quadrupole time-of-flight mass spectrometry. Metabolites were identified by matching the retention time, mass and isotope profile to authentic standards or metabolome databases using Agilent's MassHunter Find by Molecular Feature workflow (v7.0). Untargeted metabolomics identified 1006 and 1295 annotated features from the negative and positive mode respectively. Principal component analysis and orthogonal signal correction partial least-squares discriminant analysis discriminated the metabolomes of control sheep and sheep grazed in biosolid-treated pasture. The key differential metabolites identified by variable importance in projection score primarily belonged to the super-class organic acids, fatty acids, benzenoids, glycerophospholipids and organoheterocyclic compounds. These differentially expressed metabolites are implicated in metabolic pathways including carnitine synthesis, alanine metabolism, glucose alanine cycle, phosphatidyl choline biosynthesis and glutathione metabolism. Some of the top differential metabolites- oleamide, pyroglutamic acid and 15-HETrE have been implicated in fetal development. Oleamide, an endocannabinoid, has growth inhibitory properties. 15-HETrE modulates arachidonic acid metabolism and upregulate PPARγ expression, which plays a pivotal role in fetal development and metabolic outcomes. These findings indicate that biosolids exposure results in alterations in the maternal metabolome which likely contributes to the aberrant phenotypic outcomes reported in offspring of biosolid-exposed mothers. This is the first study to apply metabolomics to validate the effect of real-life EDC exposure in sheep, a translationally relevant precocial model with a developmental trajectory similar to humans. Presentation: Sunday, June 12, 2022 1:00 p.m. - 1:05 p.m., Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.