Integrative Molecular Phenotyping
INTEGRATIVE MOLECULAR
PHENOTYPING
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY

PubMed

Long chain acyl-CoA synthetase 6 facilitates the local distribution of di-docosahexaenoic acid- and ultra-long-chain-PUFA-containing phospholipids in the retina to support normal visual function in mice

Wed, 16/08/2023 - 12:00
FASEB J. 2023 Sep;37(9):e23151. doi: 10.1096/fj.202300976R.ABSTRACTDocosahexaenoic acid (DHA) and ultra-long-chain polyunsaturated fatty acids (ULC-PUFAs) are uniquely enriched in membrane phospholipids of retinal photoreceptors. Several studies have shown that di-DHA- and ULC-PUFA-containing phospholipids in photoreceptors have an important role in maintaining normal visual function; however, the molecular mechanisms underlying the synthesis and enrichment of these unique lipids in the retina, and their specific roles in retinal function remain unclear. Long-chain acyl-coenzyme A (CoA) synthetase 6 (ACSL6) preferentially converts DHA into DHA-CoA, which is a substrate during DHA-containing lipid biosynthesis. Here, we report that Acsl6 mRNA is expressed in the inner segment of photoreceptor cells and the retinal pigment epithelial cells, and genetic deletion of ACSL6 resulted in the selective depletion of di-DHA- and ULC-PUFA-containing phospholipids, but not mono-DHA-containing phospholipids in the retina. MALDI mass spectrometry imaging (MALDI-MSI) revealed the selective distribution of di-DHA- and ULC-PUFA-containing phospholipids in the photoreceptor outer segment (OS). Electroretinogram of Acsl6-/- mice exhibited photoreceptor cell-derived visual impairment, whereas the expression levels and localization of opsin proteins were unchanged. Acsl6-/- mice exhibited an age-dependent progressive decrease of the thickness of the outer nuclear layers, whereas the inner nuclear layers and OSs were normal. These results demonstrate that ACSL6 facilitates the local enrichment of di-DHA- and ULC-PUFA-containing phospholipids in the retina, which supports normal visual function and retinal homeostasis.PMID:37585289 | DOI:10.1096/fj.202300976R

Phospho-Analyst: An Interactive, Easy-to-Use Web Platform To Analyze Quantitative Phosphoproteomics Data

Wed, 16/08/2023 - 12:00
J Proteome Res. 2023 Aug 16. doi: 10.1021/acs.jproteome.3c00186. Online ahead of print.ABSTRACTPhosphoproteomics is nowadays the method of choice to comprehensively identify and quantify thousands of phosphorylated peptides and their associated proteins with the goal of interrogating changes in signal transduction pathways and other cellular processes. One of the most popular software suites to analyze phosphoproteomic data sets is MaxQuant, which converts mass spectrometric raw data into quantitative information on phosphopeptides and proteins. However, despite the increased utilization of phosphoproteomics in biomedical research, simple and user-friendly tools supporting downstream statistical analysis and interpretation of these highly complex outputs are still lacking. We have therefore developed Phospho-Analyst, which─similar to its sibling LFQ-Analyst─is an easy-to-use, interactive web application specifically designed to reproducibly perform differential expression analyses with "one click" and to visualize phosphoproteomic results in a meaningful and practical manner. Furthermore, if quantitative total proteomic information is available for the same samples, Phospho-Analyst automatically normalizes all phosphoproteomic results to underlying protein abundance levels, thereby ensuring that only genuine changes in phosphorylation events are considered. As such, Phospho-Analyst can not only be used by experienced proteomic veterans but also by researchers without any prior knowledge in (phospho)proteomics, statistics, or bioinformatics. Phospho-Analyst, including a detailed manual, is freely available at https://analyst-suites.org/apps/phospho-analyst/.PMID:37584946 | DOI:10.1021/acs.jproteome.3c00186

LORA, Lipid Over-Representation Analysis Based on Structural Information

Wed, 16/08/2023 - 12:00
Anal Chem. 2023 Aug 16. doi: 10.1021/acs.analchem.3c02039. Online ahead of print.ABSTRACTWith the increasing number of lipidomic studies, there is a need for an efficient and automated analysis of lipidomic data. One of the challenges faced by most existing approaches to lipidomic data analysis is lipid nomenclature. The systematic nomenclature of lipids contains all available information about the molecule, including its hierarchical representation, which can be used for statistical evaluation. The Lipid Over-Representation Analysis (LORA) web application (https://lora.metabolomics.fgu.cas.cz) analyzes this information using the Java-based Goslin framework, which translates lipid names into a standardized nomenclature. Goslin provides the level of lipid hierarchy, including information on headgroups, acyl chains, and their modifications, up to the "complete structure" level. LORA allows the user to upload the experimental query and reference data sets, select a grammar for lipid name normalization, and then process the data. The user can then interactively explore the results and perform lipid over-representation analysis based on selected criteria. The results are graphically visualized according to the lipidome hierarchy. The lipids present in the most over-represented terms (lipids with the highest number of enriched shared structural features) are defined as Very Important Lipids (VILs). For example, the main result of a demo data set is the information that the query is significantly enriched with "glycerophospholipids" containing "acyl 20:4" at the "sn-2 position". These terms define a set of VILs (e.g., PC 18:2/20:4;O and PE 16:0/20:4(5,8,10,14);OH). All results, graphs, and visualizations are summarized in a report. LORA is a tool focused on the smart mining of epilipidomics data sets to facilitate their interpretation at the molecular level.PMID:37584663 | DOI:10.1021/acs.analchem.3c02039

Comprehensive interrogation of human skeletal muscle reveals a dissociation between insulin resistance and mitochondrial capacity

Wed, 16/08/2023 - 12:00
Am J Physiol Endocrinol Metab. 2023 Aug 16. doi: 10.1152/ajpendo.00143.2023. Online ahead of print.ABSTRACTInsulin resistance and blunted mitochondrial capacity in skeletal muscle are often synonymous; however, this association remains controversial. The aim of this study was to perform an in-depth multi-factorial comparison of skeletal muscle mitochondrial capacity between individuals who were lean and active (Active- n = 9), individuals with obesity (Obese- n = 9) and individuals with Obesity, insulin resistance and type 2 diabetes (T2D- n = 22). Mitochondrial capacity was assessed by ex vivo mitochondrial respiration with fatty-acid and glycolytic supported protocols adjusted for mitochondrial content (mtDNA and citrate synthase activity). Supercomplex assembly was measured by BN-PAGE and immunoblot. TCA cycle intermediates were assessed with targeted metabolomics. Exploratory transcriptomics and DNA methylation analyses were performed to uncover molecular differences affecting mitochondrial function among the three groups. We reveal no discernable differences in skeletal muscle mitochondrial content, mitochondrial capacity, supercomplex assembly, TCA cycle intermediates and mitochondrial molecular profiles between obese individuals with and without T2D that had comparable levels of confounding factors (BMI, age, aerobic capacity). We highlight that lean, active individuals have greater; mitochondrial content, mitochondrial capacity, supercomplex assembly and TCA cycle intermediates. These phenotypical changes are reflected at the level of DNA methylation and gene transcription. The collective observation of comparable muscle mitochondrial capacity in individuals with obesity and T2D (vs. individuals without T2D) underscores a dissociation from skeletal muscle insulin resistance.PMID:37584609 | DOI:10.1152/ajpendo.00143.2023

Unique features of <em>Entamoeba histolytica</em> glycerophospholipid metabolism; has the <em>E</em>. <em>histolytica</em> lipid metabolism network evolved through gene loss and gain to enable parasitic life cycle adaptation?

Wed, 16/08/2023 - 12:00
mSphere. 2023 Aug 16:e0017423. doi: 10.1128/msphere.00174-23. Online ahead of print.ABSTRACTEntamoeba histolytica, a protozoan parasite, causes amoebiasis, which is a global public health problem. During the life cycle of this parasite, the properties of the cell membrane are changed markedly. To clarify the mechanism of membrane lipid changes, we exploited state-of-the-art untargeted lipidomic analysis, and atypical features of glycerophospholipids, lysoglycerophospholipids, and sphingolipids were observed compared with human equivalents. Here, we overview an entire E. histolytica glycerophospholipid metabolic pathway based on re-evaluated whole lipidome and genome along with the results of metabolic labeling experiments. We also discuss whether the E. histolytica lipid metabolism network, including the glycerophospholipid metabolic pathway, has unique features necessary for parasitic life cycle adaptation through gene loss and/or gain, and raise important questions involving biochemistry, molecular cell biology, and physiology underlying this network. Answering these questions will advance the understanding of Entamoeba physiology and will provide potential targets to develop new anti-amoebiasis drugs.PMID:37584599 | DOI:10.1128/msphere.00174-23

Metabolomics analysis of mycelial exudates provides insights into fungal antagonists of <em>Armillaria</em>

Wed, 16/08/2023 - 12:00
Mycology. 2023 Jul 29;14(3):264-274. doi: 10.1080/21501203.2023.2238753. eCollection 2023.ABSTRACTThe genus Armillaria has high edible and medical values, with zones of antagonism often occurring when different species are paired in culture on agar media, while the antagonism-induced metabolic alteration remains unclear. Here, the metabolome of mycelial exudates of two Chinese Armillaria biological species, C and G, co-cultured or cultured separately was analysed to discover the candidate biomarkers and the key metabolic pathways involved in Armillaria antagonists. A total of 2,377 metabolites were identified, mainly organic acids and derivatives, lipids and lipid-like molecules, and organoheterocyclic compounds. There were 248 and 142 differentially expressed metabolites between group C-G and C, C-G, and G, respectively, and fourteen common differentially expressed metabolites including malate, uracil, Leu-Gln-Arg, etc. Metabolic pathways like TCA cycle and pyrimidine metabolism were significantly affected by C-G co-culture. Additionally, 156 new metabolites (largely organic acids and derivatives) including 32 potential antifungal compounds, primarily enriched into biosynthesis of secondary metabolites pathways were identified in C-G co-culture mode. We concluded that malate and uracil could be used as the candidate biomarkers, and TCA cycle and pyrimidine metabolism were the key metabolic pathways involved in Armillaria antagonists. The metabolic changes revealed in this study provide insights into the mechanisms underlying fungal antagonists.PMID:37583453 | PMC:PMC10424624 | DOI:10.1080/21501203.2023.2238753

High preoperative blood oxaloacetate and 2-aminoadipic acid levels are associated with postoperative delayed neurocognitive recovery

Wed, 16/08/2023 - 12:00
Front Endocrinol (Lausanne). 2023 Jul 31;14:1212815. doi: 10.3389/fendo.2023.1212815. eCollection 2023.ABSTRACTINTRODUCTION: This study aimed to identify preoperative blood biomarkers related to development of delayed neurocognitive recovery (dNCR) following surgery.METHODS: A total of 67 patients (≥65 years old) who underwent head and neck tumor resection under general anesthesia were assessed using the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). Preoperative serum metabolomics were determined using widely targeted metabolomics technology.RESULTS: Of the 67 patients, 25 developed dNCR and were matched to 25 randomly selected patients from the remaining 42 without dNCR. Differential metabolites were selected using the criteria of variable importance in projection > 1.0 in orthogonal partial least squares discrimination analysis, false discovery rate <0.05, and fold-change >1.2 or <0.83 to minimize false positives. Preoperative serum levels of oxaloacetate (OR: 1.054, 95% CI: 1.027-1.095, P = 0.001) and 2-aminoadipic acid (2-AAA) (OR: 1.181, 95% CI: 1.087-1.334, P = 0.001) were associated with postoperative dNCR after adjusting for anesthesia duration, education, and age. Areas under the curve for oxaloacetate and 2-AAA were 0.86 (sensitivity: 0.84, specificity: 0.88) and 0.86 (sensitivity: 0.84, specificity: 0.84), respectively. High levels of preoperative oxaloacetate and 2-AAA also were associated with postoperative decreased MoCA (β: 0.022, 95% CI: 0.005-0.04, P = 0.013 for oxaloacetate; β: 0.077, 95%CI: 0.016-0.137, P = 0.014 for 2-AAA) and MMSE (β: 0.024, 95% CI: 0.009-0.039, P = 0.002 for oxaloacetate; β: 0.083, 95% CI: 0.032-0.135, P = 0.002 for 2-AAA) scores after adjusting for age, education level, and operation time.CONCLUSION: High preoperative blood levels of oxaloacetate and 2-AAA were associated with increased risk of postoperative dNCR.CLINICAL TRIAL REGISTRATION: https://classic.clinicaltrials.gov/ct2/show/NCT05105451, identifier NCT05105451.PMID:37583434 | PMC:PMC10424917 | DOI:10.3389/fendo.2023.1212815

Use of carbon-13 NMR to identify known natural products by querying a nuclear magnetic resonance database-An assessment

Wed, 16/08/2023 - 12:00
Magn Reson Chem. 2023 Aug 15. doi: 10.1002/mrc.5386. Online ahead of print.ABSTRACTThe quick identification of known organic low molecular weight compounds, also known as structural dereplication, is a highly important task in the chemical profiling of natural resource extracts. To that end, a method that relies on carbon-13 nuclear magnetic resonance (NMR) spectroscopy, elaborated in earlier works of the author's research group, requires the availability of a dedicated database that establishes relationships between chemical structures, biological and chemical taxonomy, and spectroscopy. The construction of such a database, called acd_lotus, was reported earlier, and its usefulness was illustrated by only three examples. This article presents the results of structure searches carried out starting from 58 carbon-13 NMR data sets recorded on compounds selected in the metabolomics section of the biological magnetic resonance bank (BMRB). Two compound retrieval methods were employed. The first one involves searching in the acd_lotus database using commercial software. The second one operates through the freely accessible web interface of the nmrshiftdb2 database, which includes the compounds present in acd_lotus and many others. The two structural dereplication methods have proved to be efficient and can be used together in a complementary way.PMID:37583258 | DOI:10.1002/mrc.5386

Recent Updates on the Management of Adrenal Incidentalomas

Wed, 16/08/2023 - 12:00
Endocrinol Metab (Seoul). 2023 Aug 16. doi: 10.3803/EnM.2023.1779. Online ahead of print.ABSTRACTAdrenal incidentalomas represent an increasingly common clinical conundrum with significant implications for patients. The revised 2023 European Society of Endocrinology (ESE) guideline incorporates cutting-edge evidence for managing adrenal incidentalomas. This paper provides a concise review of the updated contents of the revised guideline. In the 2023 guideline, in patients without signs and symptoms of overt Cushing's syndrome, a post-dexamethasone cortisol level above 50 nmol/L (>1.8 μg/dL) should be considered as mild autonomous cortisol secretion. Regarding the criteria of benign adrenal adenomas, a homogeneous adrenal mass with ≤10 Hounsfield units on non-contrast computed tomography requires no further follow-up, irrespective of its size. The updated guideline also discusses steroid metabolomics using tandem mass spectrometry to discriminate malignancy. It underscores the importance of high-volume surgeons performing adrenalectomy and emphasizes the pivotal role of a multidisciplinary team approach in deciding the treatment plan for indeterminate adrenal masses. The guideline advocates for more proactive surgical treatment for indeterminate adrenal masses in young patients (<40 years) and pregnant women. This review of the 2023 ESE guideline underscores the ongoing evolution of the adrenal incidentaloma management landscape, emphasizing the need for further research and adaptation of diagnostic and therapeutic strategies.PMID:37583083 | DOI:10.3803/EnM.2023.1779

The metabolic control of DNA replication: mechanism and function

Tue, 15/08/2023 - 12:00
Open Biol. 2023 Aug;13(8):230220. doi: 10.1098/rsob.230220. Epub 2023 Aug 16.ABSTRACTMetabolism and DNA replication are the two most fundamental biological functions in life. The catabolic branch of metabolism breaks down nutrients to produce energy and precursors used by the anabolic branch of metabolism to synthesize macromolecules. DNA replication consumes energy and precursors for faithfully copying genomes, propagating the genetic material from generation to generation. We have exquisite understanding of the mechanisms that underpin and regulate these two biological functions. However, the molecular mechanism coordinating replication to metabolism and its biological function remains mostly unknown. Understanding how and why living organisms respond to fluctuating nutritional stimuli through cell-cycle dynamic changes and reproducibly and distinctly temporalize DNA synthesis in a wide-range of growth conditions is important, with wider implications across all domains of life. After summarizing the seminal studies that founded the concept of the metabolic control of replication, we review data linking metabolism to replication from bacteria to humans. Molecular insights underpinning these links are then presented to propose that the metabolic control of replication uses signalling systems gearing metabolome homeostasis to orchestrate replication temporalization. The remarkable replication phenotypes found in mutants of this control highlight its importance in replication regulation and potentially genetic stability and tumorigenesis.PMID:37582405 | DOI:10.1098/rsob.230220

Protein-metabolite association studies identify novel proteomic determinants of metabolite levels in human plasma

Tue, 15/08/2023 - 12:00
Cell Metab. 2023 Aug 11:S1550-4131(23)00271-1. doi: 10.1016/j.cmet.2023.07.012. Online ahead of print.ABSTRACTAlthough many novel gene-metabolite and gene-protein associations have been identified using high-throughput biochemical profiling, systematic studies that leverage human genetics to illuminate causal relationships between circulating proteins and metabolites are lacking. Here, we performed protein-metabolite association studies in 3,626 plasma samples from three human cohorts. We detected 171,800 significant protein-metabolite pairwise correlations between 1,265 proteins and 365 metabolites, including established relationships in metabolic and signaling pathways such as the protein thyroxine-binding globulin and the metabolite thyroxine, as well as thousands of new findings. In Mendelian randomization (MR) analyses, we identified putative causal protein-to-metabolite associations. We experimentally validated top MR associations in proof-of-concept plasma metabolomics studies in three murine knockout strains of key protein regulators. These analyses identified previously unrecognized associations between bioactive proteins and metabolites in human plasma. We provide publicly available data to be leveraged for studies in human metabolism and disease.PMID:37582364 | DOI:10.1016/j.cmet.2023.07.012

Methionine orchestrates the metabolism vulnerability in cisplatin resistant bladder cancer microenvironment

Tue, 15/08/2023 - 12:00
Cell Death Dis. 2023 Aug 15;14(8):525. doi: 10.1038/s41419-023-06050-1.ABSTRACTMetabolism vulnerability of cisplatin resistance in BCa cells remains to be discovered, which we applied integrated multi-omics analysis to elucidate the metabolism related regulation mechanism in bladder cancer (BCa) microenvironment. Integrated multi-omics analysis of metabolomics and proteomics revealed that MAT2A regulated methionine metabolism contributes to cisplatin resistance in BCa cells. We further validated MAT2A and cancer stem cell markers were up-regulated and circARHGAP10 was down-regulated through the regulation of MAT2A protein stability in cisplatin resistant BCa cells. circARHGAP10 formed a complex with MAT2A and TRIM25 to accelerate the degradation of MAT2A through ubiquitin-proteasome pathway. Knockdown of MAT2A through overexpression of circARHGAP10 and restriction of methionine up-take was sufficient to overcome cisplatin resistance in vivo in immuno-deficiency model but not in immuno-competent model. Tumor-infiltrating CD8+ T cells characterized an exhausted phenotype in tumors with low methionine. High expression of SLC7A6 in BCa negatively correlated with expression of CD8. Synergistic inhibition of MAT2A and SLC7A6 could overcome cisplatin resistance in immuno-competent model in vivo. Cisplatin resistant BCa cells rely on methionine for survival and stem cell renewal. circARHGAP10/TRIM25/MAT2A regulation pathway plays an important role in cisplatin resistant BCa cells while circARHGAP10 and SLC7A6 should be evaluated as one of the therapeutic target of cisplatin resistant BCa.PMID:37582769 | DOI:10.1038/s41419-023-06050-1

Correlation analysis of aqueous humor metabolomics with myopic axial length and choroidal parameters

Tue, 15/08/2023 - 12:00
BMC Ophthalmol. 2023 Aug 15;23(1):356. doi: 10.1186/s12886-023-03101-1.ABSTRACTBACKGROUND: To explore differential metabolites in the aqueous humor of patients with different axial lengths and their correlations with axial length and choroidal parameters.METHODS: In this study, we included 12 patients with axial lengths less than 24 mm, 11 patients with axial lengths between 24 and 26 mm, and 11 patients with axial lengths greater than 26 mm. We collected their aqueous humor samples during cataract surgery for liquid chromatography-mass spectrometry metabolomic analysis. Simultaneously, we collected relevant clinical parameters such as axial length, subfoveal choroidal thickness, and choroidal vascular index. Correlations between clinical data, differential metabolites, and clinical indicators were analyzed. In addition, we plotted receiver operating characteristic curves.RESULTS: The results showed that axial length was significantly negatively correlated with choroidal thickness (r=-0.7446, P < 0.0001), and that several differential metabolites were significantly correlated with certain clinical parameters. After analyzing receiver operating characteristic curves, 5-methoxytryptophol and cerulenin were found to have excellent discriminative power, demonstrating their potential as biomarkers. In the enrichment analysis, we found that the differential metabolites among each group were involved in several special pathways (Taurine and Hypotaurine Metabolism, Vitamin B6 Metabolism, Pantothenate, and coenzyme A Biosynthesis), suggesting that abnormalities in these metabolic pathways may play a role in the process of axial myopia.CONCLUSIONS: Our study identified alterations in certain metabolic pathways in different axial lengths. At the same time, we found several metabolites with significant correlation with clinical indicators, among which 5-methoxytryptophol and cerulenin were associated with axial myopia.CLINICAL TRIAL REGISTRATION: Registration date:11/04/2022.TRIAL REGISTRATION NUMBER: ChiCTR2200058575.TRIAL REGISTRY: The First Affiliated Hospital of the Zhejiang University School of Medicine.PMID:37582698 | DOI:10.1186/s12886-023-03101-1

Improving Quantitative Accuracy in Nontargeted Lipidomics by Evaluating Adduct Formation

Tue, 15/08/2023 - 12:00
Anal Chem. 2023 Aug 15. doi: 10.1021/acs.analchem.3c01221. Online ahead of print.ABSTRACTFor large-scale lipidomic analyses, accurate and reproducible quantification of endogenous lipids is crucial for comparing results within and across studies. Many lipids present in liquid chromatography-electrospray ionization-mass spectrometry form various adducts with buffer components. The mechanisms and conditions that dictate adduct formation are still poorly understood. In a positive mode, neutral lipids like mono-, di-, and triacylglycerides and cholesteryl esters typically generate [M + NH4]+ adduct ions, although [M + Na]+, [M + K]+, and other (more complex) species can also be significantly abundant in MS1 precursor ion spectra. Variations in the ratios of these adducts (within and between matrices) can lead to dramatic inaccuracies during quantification. Here, we examine 48 unique diacylglycerol (DAG) species across 2366 mouse samples for eight matrix-specific data sets of plasma, liver, kidney, brain, heart muscle, gastrocnemius muscle, gonadal, and inguinal fat. Typically, no single adduct ion species accounted for more than 60% of the total observed abundance across each data set. Even within a single matrix, DAGs showed a high variability of adduct ratios. The ratio of [M + NH4]+ adduct ions was increased for longer-chain DAGs and for polyunsaturated DAGs, at the expense of reduced ratios of [M + Na]+ adducts. When using three deuterated internal DAG standards, we found that absolute concentrations were estimated with up to 70% error when only one adduct ion was used instead of all adducts combined. Importantly, when combining [M + NH4]+ and [M + Na]+ adduct ions, quantification results were within 5% accuracy compared to all adduct ions combined. Additional variance can be caused by other factors, such as instrument conditions or matrix effects.PMID:37582244 | DOI:10.1021/acs.analchem.3c01221

Anomalous Dynamics of Labile Metabolites in Cold Human Blood Detected Using <sup>1</sup>H NMR Spectroscopy

Tue, 15/08/2023 - 12:00
Anal Chem. 2023 Aug 15. doi: 10.1021/acs.analchem.3c02478. Online ahead of print.ABSTRACTRecent efforts in our laboratory have enabled access to an unprecedented number (∼90) of quantifiable metabolites in human blood by a simple nuclear magnetic resonance (NMR) spectroscopy method, which includes energy coenzymes, redox coenzymes, and antioxidants that are fundamental to cellular functions [ J. Magn. Reson. Open 2022, 12-13, 100082]. The coenzymes and antioxidants, however, are notoriously labile and are extremely sensitive to specimen harvesting, extraction, and measurement conditions. This problem is largely underappreciated and carries the risk of grossly inaccurate measurements and incorrect study outcomes. As a part of addressing this challenge, in this study, human blood specimens were comprehensively and quantitatively investigated using 1H NMR spectroscopy. Freshly drawn human blood specimens were treated or not treated with methanol, ethanol, or a mixture of methanol and chloroform, and stored on ice or on bench, at room temperature for different time periods from 0 to 24 h, prior to storing at -80 °C. Interestingly, the labile metabolite levels were stable in blood treated with an organic solvent. However, their levels in blood in untreated samples increased or decreased by factors of up to 5 or more within 3 h. Further, surprisingly, and contrary to the current knowledge about metabolite stability, the variation of coenzyme levels was more dramatic in blood stored on ice than on bench, at room temperature. In addition, unlike the generally observed phenomenon of oxidation of redox coenzymes, reduction was observed in untreated blood. Such preanalytical dynamics of the labile metabolites potentially arises from the active cellular metabolism. From the metabolomics perspective, the massive variation of the labile metabolite levels even in blood stored on ice is alarming and stresses the critical need to immediately quench the cellular metabolism for reliable analyses. Overall, the results provide compelling evidence that warrants a paradigm shift in the sample collection protocol for blood metabolomics involving labile metabolites.PMID:37582233 | DOI:10.1021/acs.analchem.3c02478

Variability of the Human Serum Metabolome over 3 Months in the EXPOsOMICS Personal Exposure Monitoring Study

Tue, 15/08/2023 - 12:00
Environ Sci Technol. 2023 Aug 15. doi: 10.1021/acs.est.3c03233. Online ahead of print.ABSTRACTLiquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS) and untargeted metabolomics are increasingly used in exposome studies to study the interactions between nongenetic factors and the blood metabolome. To reliably and efficiently link detected compounds to exposures and health phenotypes in such studies, it is important to understand the variability in metabolome measures. We assessed the within- and between-subject variability of untargeted LC-HRMS measurements in 298 nonfasting human serum samples collected on two occasions from 157 subjects. Samples were collected ca. 107 (IQR: 34) days apart as part of the multicenter EXPOsOMICS Personal Exposure Monitoring study. In total, 4294 metabolic features were detected, and 184 unique compounds could be identified with high confidence. The median intraclass correlation coefficient (ICC) across all metabolic features was 0.51 (IQR: 0.29) and 0.64 (IQR: 0.25) for the 184 uniquely identified compounds. For this group, the median ICC marginally changed (0.63) when we included common confounders (age, sex, and body mass index) in the regression model. When grouping compounds by compound class, the ICC was largest among glycerophospholipids (median ICC 0.70) and steroids (0.67), and lowest for amino acids (0.61) and the O-acylcarnitine class (0.44). ICCs varied substantially within chemical classes. Our results suggest that the metabolome as measured with untargeted LC-HRMS is fairly stable (ICC > 0.5) over 100 days for more than half of the features monitored in our study, to reflect average levels across this time period. Variance across the metabolome will result in differential measurement error across the metabolome, which needs to be considered in the interpretation of metabolome results.PMID:37582220 | DOI:10.1021/acs.est.3c03233

Metabolomic analysis of pig spleen reveals African swine fever virus infection increased acylcarnitine levels to facilitate viral replication

Tue, 15/08/2023 - 12:00
J Virol. 2023 Aug 15:e0058623. doi: 10.1128/jvi.00586-23. Online ahead of print.ABSTRACTAfrican swine fever (ASF) is a devastating disease caused by the African swine fever virus (ASFV) that adversely affects the pig industry. The spleen is the main target organ of ASFV; however, the function of metabolites in the spleen during ASFV infection is yet to be investigated. To define the metabolic changes in the spleen after ASFV infection, untargeted and targeted metabolomics analyses of spleens from ASFV-infected pigs were conducted. Untargeted metabolomics analysis revealed 540 metabolites with significant differential levels. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that these metabolites were mainly enriched in metabolic pathways, including nucleotide metabolism, purine metabolism, arginine biosynthesis, and neuroactive ligand-receptor interaction. Moreover, 134 of 540 metabolites quantified by targeted metabolomics analysis had differential levels and were enriched in metabolic pathways such as the biosynthesis of cofactors, ABC transporters, and biosynthesis of amino acids. Furthermore, coalition analysis of untargeted and targeted metabolomics data revealed that the levels of acylcarnitines, which are intermediates of fatty acid β-oxidation, were significantly increased in ASFV-infected spleens compared with those in the uninfected spleens. Moreover, inhibiting fatty acid β-oxidation significantly reduced ASFV replication, indicating that fatty acid β-oxidation is essential for this process. To our knowledge, this is the first report presenting the metabolite profiles of ASFV-infected pigs. This study revealed a new mechanism of ASFV-mediated regulation of host metabolism. These findings provide new insights into the pathogenic mechanisms of ASFV, which will benefit the development of target drugs for ASFV replication. IMPORTANCE African swine fever virus, the only member of the Asfarviridae family, relies on hijacking host metabolism to meet the demand for self-replication. However, the change in host metabolism after African swine fever virus (ASFV) infection remains unknown. Here, we analyzed the metabolic changes in the pig spleen after ASFV infection for the first time. ASFV infection increased the levels of acylcarnitines. Inhibition of the production and metabolism of acylcarnitines inhibited ASFV replication. Acylcarnitines are the vital intermediates of fatty acid β-oxidation. This study highlights the critical role of fatty acid β-oxidation in ASFV infection, which may help identify target drugs to control African swine fever disease.PMID:37582206 | DOI:10.1128/jvi.00586-23

Design, Synthesis, and Biological Evaluation of Novel P2X7 Receptor Antagonists for the Treatment of Septic Acute Kidney Injury

Tue, 15/08/2023 - 12:00
J Med Chem. 2023 Aug 15. doi: 10.1021/acs.jmedchem.3c00837. Online ahead of print.ABSTRACTSepsis-associated acute kidney injury (AKI) is a serious clinical problem, without effective drugs. Abnormal activation of the purinergic P2X7 receptor (P2X7R) in septic kidneys makes its antagonist a promising therapeutic approach. Herein, a series of novel P2X7R antagonists were designed, synthesized, and structurally optimized. Based on in vitro potency in human/mouse P2X7R using HEK293 cells, hepatic microsomal stability, and pharmacokinetic and preliminary in vivo assessments, compound 14a was identified by respective human and mouse P2X7R IC50 values of 64.7 and 10.1 nM, together with favorable pharmacokinetic properties. Importantly, 14a dose-dependently alleviated kidney dysfunction and pathological injury in both lipopolysaccharide (LPS)- and cecal ligation/perforation (CLP)-induced septic AKI mice with a good safety profile. Mechanistically, 14a could suppress NLRP3 inflammasome activation to inhibit the expression of cleaved caspase-1, gasdermin D, IL-1β, and IL-18 in the injured kidneys of septic mice. Collectively, these results highlighted that P2X7R antagonist 14a exerted a therapeutic potential against septic AKI.PMID:37582195 | DOI:10.1021/acs.jmedchem.3c00837

GC-MS analysis of fatty acid metabolomics in RAW264.7 cell inflammatory model intervened by non-steroidal anti-inflammatory drugs and a preliminary study on the anti-inflammatory effects of NLRP3 signaling pathway

Tue, 15/08/2023 - 12:00
PLoS One. 2023 Aug 15;18(8):e0290051. doi: 10.1371/journal.pone.0290051. eCollection 2023.ABSTRACTTo explore the metabolomics of fatty acids and biological information of related markers in a RAW264.7 cell inflammation model. RAW264.7 macrophage inflammation model was induced by LPS, and RAW264.7 cells were treated with non-steroidal anti-inflammatory drugs (NSAIDs). The fatty acid compositions were identified by GC-MS, combined with standard product spectrum information and NIST (National Institute of Standards and Technology) database. Using chemometrics and Analysis of Variance (ANOVA), the components with VIP > 1 and P < 0.05 were selected as significant difference markers, and combined with biological methods to explore the biological significance of them. GC-MS identified 21 fatty acids in RAW264.7 cells, and screened significant difference biomarkers in each group. Among these biomarkers, C20:5 and C22:6 had significant changes in pairwise comparison among each group. Through ELISA, polymerase chain reaction (PCR) and Western Blot methods, the mRNA and protein expressions of IL-1β, NLRP3, GPR120 and β-Arrestin-2 were up-regulated after RAW264.7 cells induced by LPS and nigericin, and decreased after drug intervention. It indicated that the signal pathway centered on NLRP3 inflammasome was involved in the anti-inflammatory process of ibuprofen. It was the first time to study fatty acid metabolomics in RAW264.7 cell inflammatory model by GC-MS combined with chemometrics. The anti-inflammatory mechanism of ibuprofen was explained from NLRP3 inflammasome perspective without precedent, which enriched the research on the signal pathway of ibuprofen anti-inflammatory mechanism.PMID:37582087 | DOI:10.1371/journal.pone.0290051

Modulating the polyamine-hypusine axis controls generation of CD8+ tissue resident memory T cells

Tue, 15/08/2023 - 12:00
JCI Insight. 2023 Aug 15:e169308. doi: 10.1172/jci.insight.169308. Online ahead of print.ABSTRACTGlutaminolysis is a hallmark of the activation and metabolic reprogramming of T cells. Isotopic tracer analyses of antigen-activated effector CD8+ T cells revealed that glutamine is the principal carbon source for the biosynthesis of polyamines putrescine, spermidine and spermine. These metabolites play critical roles in activation-induced T-cell proliferation, as well as for the production of hypusine, which is derived from spermidine and is covalently linked to the translation elongation factor eIF5A. Here, we demonstrated that the glutamine-polyamine-hypusine axis controls the expression of CD69, an important regulator of tissue resident memory T cells (TRM). Inhibition of this circuit augmented the development of TRM cells ex vivo and in vivo in the bone marrow, a well-established niche for TRM cells. Furthermore, blocking the polyamine-hypusine axis augmented CD69 expression and IFN-γ and TNF-α production in human CD8+ T cells from peripheral blood and sarcoma tumor infiltrating lymphocytes, as well as in human CD8+ CAR-T cells. Collectively, these findings support the notion that the polyamine-hypusine circuit can be exploited to modulate TRM cells for therapeutic benefit.PMID:37581943 | DOI:10.1172/jci.insight.169308

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