Metabolites

16 pages, 2024 KB

Open AccessArticle

Untargeted LC–HRMS of Dried Blood Spots Reveals Metabolic Alterations and Candidate Biomarkers in Glutaric Aciduria Type-1

by Ahmed H. Mujamammi, Tagreed A. Mazi, Reem H. AlMalki, Essa M. Sabi, Maha Al Mogren, Meshari Alwazae, Randh AlAhmari, Khalid M. Sumaily, Rajaa Sebaa and Anas M. Abdel Rahman

Metabolites 2026, 16(3), 214; https://doi.org/10.3390/metabo16030214 - 23 Mar 2026

Viewed by 1406

Abstract

Background: Glutaric aciduria type-1 (GA-1) is a genetic disorder caused by glutaryl-coenzyme A dehydrogenase deficiency, leading to the accumulation of glutaryl-CoA and its derivatives. Clinical manifestations include neurological abnormalities; however, the underlying pathological mechanisms remain unclear. Early diagnosis and intervention are crucial [...] Read more.

Background: Glutaric aciduria type-1 (GA-1) is a genetic disorder caused by glutaryl-coenzyme A dehydrogenase deficiency, leading to the accumulation of glutaryl-CoA and its derivatives. Clinical manifestations include neurological abnormalities; however, the underlying pathological mechanisms remain unclear. Early diagnosis and intervention are crucial for minimizing adverse outcomes. To date, diagnostic methods have certain limitations, and there is a critical need for a sensitive biomarker for diagnosis. We aimed to characterize metabolic dysregulation and identify candidate biomarkers associated with GA-1 in biochemically confirmed patients compared to age- and sex-matched control subjects. Methodology: Untargeted metabolomics profiling of GA-1 patients (n = 29) was compared to matched control subjects by age and sex. Multivariate and univariate statistical analyses were performed to identify dysregulated metabolites. Results: Our findings revealed 220 endogenous human metabolites. Notably, there was a strong enrichment in carboxylic acids and derivatives, including amino acids and derivatives, hydroxy and keto acids, fatty acyls, sphingolipids, phosphatidylcholines, and nucleotides and nucleosides. Pathway analysis indicates alterations in the biosynthesis of cardiolipin and phosphatidylcholine, as well as in pyrimidine metabolism, the urea cycle, and amino sugar metabolism. We demonstrated a robust performance model for 6-Methylnonanoyl-CoA, displaying strong discriminative power. Conclusions: We identified broad dysregulation across various biochemical classes, reflecting an imbalance in energy metabolism that involves carbohydrate and lipid pathways. The results also highlight dysregulation in sphingolipids, phospholipids, and nucleotide metabolism. These findings are preliminary and the clinical relevance of these findings in patients with GA-1 requires further investigation. We identified candidate biomarkers capable of distinguishing GA-1 patients from controls; however, these findings require validation in independent cohorts. Full article

(This article belongs to the Section Endocrinology and Clinical Metabolic Research)

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14 pages, 1072 KB

Open AccessArticle

Preliminary Safety Assessment for Mandarin Orange Peel Administration to Dogs Based on Physical Conditions and Blood Examination Parameters

by Tomohiro Yonezawa, Yixue Lei, Cris Niño Bon B. Marasigan, Mao Komori, Nanasa Fujiwara, Jun Nakahigashi and Eiji Kobayashi

Metabolites 2026, 16(3), 213; https://doi.org/10.3390/metabo16030213 - 23 Mar 2026

Cited by 1 | Viewed by 1329

Abstract

Background/Objectives: Mandarin orange peel (MOP) is rich in bioactive polymethoxyflavones, including hesperidin and nobiletin, which have shown neuroprotective effects in rodent models. However, comprehensive safety data in dogs are required to support its development as a therapeutic intervention for canine cognitive dysfunction syndrome. [...] Read more.

Background/Objectives: Mandarin orange peel (MOP) is rich in bioactive polymethoxyflavones, including hesperidin and nobiletin, which have shown neuroprotective effects in rodent models. However, comprehensive safety data in dogs are required to support its development as a therapeutic intervention for canine cognitive dysfunction syndrome. In this study, the safety profile of a standardized MOP formulation was evaluated in four healthy Beagle dogs. Methods: Initially, compositional analysis was performed, and 202 pesticide residues and psoralens were screened to ensure compliance with Japanese pet food safety standards. Subsequently, a dose-escalation study was conducted in which dogs received oral MOP at 2, 6, and 10 g/head/day for 3–4 weeks at each dose level. Clinical signs, hematology, and serum biochemistry were monitored throughout the study period. Results: The MOP powder composition and residue levels remained within regulatory safety limits. In the dose-escalation study, no significant dose-dependent abnormalities were observed in physical or clinicopathological parameters. One dog exhibited transient loose stools at higher doses and a temporary elevation in alkaline phosphatase levels at 2 g/head/day; however, these symptoms resolved spontaneously despite continued administration. Conclusions: MOP was safe and well tolerated in dogs even at 10 g/head/day (787–952 mg/kg/day), which is approximately five times the anticipated clinical dose. The observed fluctuations in active ingredient concentrations remained within the acceptable range for natural products and did not affect overall safety. Combined with comprehensive screening for residues, these results indicate that MOP is a high-quality and safe dietary intervention for older dogs. Full article

(This article belongs to the Section Animal Metabolism)

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19 pages, 693 KB

Open AccessReview

Gut Microbiota–Bile Acid Axis in Type 2 Diabetes–Associated Gallbladder Diseases: Mechanisms and Therapeutic Potential

by Qian Zhang and Zhesi Jin

Metabolites 2026, 16(3), 212; https://doi.org/10.3390/metabo16030212 - 21 Mar 2026

Cited by 2 | Viewed by 1869

Abstract

Gallbladder diseases spanning cholelithiasis, cholecystitis, and gallbladder cancer represent a clinically heterogeneous continuum in which type 2 diabetes mellitus (T2DM) acts as a key metabolic modifier. Conventional models centered on bile supersaturation alone do not sufficiently account for the persistent inflammation and inter-individual [...] Read more.

Gallbladder diseases spanning cholelithiasis, cholecystitis, and gallbladder cancer represent a clinically heterogeneous continuum in which type 2 diabetes mellitus (T2DM) acts as a key metabolic modifier. Conventional models centered on bile supersaturation alone do not sufficiently account for the persistent inflammation and inter-individual variability frequently observed in practice. Here, we synthesize emerging evidence implicating the gut microbiota–bile acid (BA) axis as an integrative mechanism linking metabolic dysregulation, barrier dysfunction, and biliary pathobiology in the diabetic host. Hyperglycemia and insulin resistance, together with impaired mucosal resilience, are associated with shifts in microbial community structure and BA-transforming functions (e.g., bile salt hydrolase and 7α-dehydroxylation), favoring a more hydrophobic BA pool. These changes may disrupt BA receptor signaling, including FXR–FGF15/19 and TGR5-related pathways, thereby amplifying metabolic inflammation, promoting lithogenic bile formation, and impairing gallbladder motility. In parallel, barrier vulnerability may facilitate microbial translocation and LPS-driven immune activation, reinforcing a feed-forward loop that supports the gallstone–inflammation–carcinogenesis trajectory. Translationally, microbiome- and BA-oriented strategies (dietary patterns, bile acid therapeutics, and targeted microbiome modulation) are promising adjuncts, yet precision management should explicitly consider medication- and weight loss–related confounding—particularly with incretin-based therapies—to optimize biliary outcomes across disease stages. Full article

(This article belongs to the Section Thematic Reviews)

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23 pages, 1917 KB

Open AccessArticle

Sex-Driven Variation in Polar Metabolites and Lipid Motifs of Paracentrotus lividus Gonads Profiled by ¹H NMR

by Ricardo Ibanco-Cañete, Estela Carbonell-Garzón, Sergio Amorós-Trujillo, Pablo Sanchez-Jerez and Frutos Carlos Marhuenda Egea

Metabolites 2026, 16(3), 211; https://doi.org/10.3390/metabo16030211 - 21 Mar 2026

Viewed by 1128

Abstract

Background/Objectives: Sea urchin gonads (“roe”) are a valuable seafood product and a chemically complex matrix whose composition varies with physiology and environment. We present a biphasic extraction and ¹H NMR workflow to build a reusable reference inventory of polar metabolites and apolar [...] Read more.

Background/Objectives: Sea urchin gonads (“roe”) are a valuable seafood product and a chemically complex matrix whose composition varies with physiology and environment. We present a biphasic extraction and ¹H NMR workflow to build a reusable reference inventory of polar metabolites and apolar lipid features in Paracentrotus lividus. Methods: Gonads from 37 adults (23 males, 14 females) collected at two sites (Alicante and Jávea–Dénia, Spain; October 2024) were lyophilized, extracted with methanol/chloroform/water, and analyzed by 400 MHz ¹H NMR in buffered aqueous solution (polar) and CDCl₃ (apolar). Polar metabolite identification combined 1D patterns with database matching and ¹H–¹³C HSQC confirmation on representative samples, yielding 71 annotated resonances corresponding to 37 metabolites spanning amino acids, osmolytes/quaternary amines, carbohydrates/aminosugars, and nucleoside/purine-related compounds. Results: Polar fingerprints enabled supervised modelling: PLS-LDA separated sexes with low cross-validated error, and SPA/COSS ranking highlighted glycine, alanine, creatine and osmolyte-associated signals as key discriminants; pathway mapping supported the enrichment of amino-acid and one-carbon/purine networks. Apolar spectra were annotated at the motif level and used for lipid-index estimation, indicating substantial unsaturation but low docosahexaenoic acid (DHA) and modest sex effects. Conclusions: The curated peak lists and reporting framework facilitate reproducible NMR annotation and future comparative studies of P. lividus gonads. Full article

(This article belongs to the Special Issue Nutrition, Metabolism and Physiology in Aquatic Animals)

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23 pages, 1139 KB

Open AccessArticle

Pharmacometabolomics Detects Unreported Clopidogrel Metabolites in the Urine of Kidney and Liver Transplant Recipients

by Cassandra Piccolotto, Stephan J. L. Bakker, Vincent E. de Meijer, Gérard Hopfgartner, Peter Fodran, Frank Klont and TransplantLines Investigators

Metabolites 2026, 16(3), 210; https://doi.org/10.3390/metabo16030210 - 21 Mar 2026

Cited by 1 | Viewed by 1169

Abstract

Background/Objectives: Clopidogrel is a widely prescribed antiplatelet prodrug that requires bioactivation, primarily by the polymorphic CYP2C19 enzyme. Genetic variation in this enzyme leads to differences in active metabolite formation and has prompted the development of pharmacogenetics-guided prescribing. However, current pharmacogenetic strategies are [...] Read more.

Background/Objectives: Clopidogrel is a widely prescribed antiplatelet prodrug that requires bioactivation, primarily by the polymorphic CYP2C19 enzyme. Genetic variation in this enzyme leads to differences in active metabolite formation and has prompted the development of pharmacogenetics-guided prescribing. However, current pharmacogenetic strategies are grounded in drug metabolism knowledge derived from mass balance studies conducted in small groups of healthy volunteers. This narrow evidence base may limit the data’s applicability to real-world settings, where factors like polypharmacy or altered organ function may influence drug response. Methods: Pharmacogenetics could benefit from real-world drug metabolism and excretion studies, which we conducted for clopidogrel in 38 kidney and 16 liver transplant recipients from the TransplantLines Biobank and Cohort Study (NCT03272841), utilizing existing LC-SWATH/MS pharmacometabolomic data. Clopidogrel-associated metabolic signals were identified using xenobiotic metabolism knowledge and literature-reported pathways. Results: Across both transplant groups, 26 clopidogrel-associated features were prioritized, of which some matched previously reported urinary metabolites, had previously been observed in plasma, or represented previously unreported metabolites. Clopidogrel carboxylic acid predominated in kidney transplant recipients, whereas its glucuronide form was most abundant in liver transplant recipients. Notably, unmetabolized clopidogrel was consistently detected across all patients. Moreover, our data support a thiol desulfurization route, aligning with emerging evidence of clopidogrel’s role as a hydrogen sulfide-releasing drug. Conclusions: More (putative) clopidogrel metabolites were detected than previously reported, demonstrating the value of pharmacometabolomics in expanding our understanding of drug metabolism. This approach provides novel data that may complement pharmacogenetics research to understand clopidogrel response variability among treated patients. Full article

(This article belongs to the Special Issue Applications of Mass Spectrometry in Elucidating Human Drug Metabolism: From the Preclinical Phase to Real-World Studies)

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22 pages, 302 KB

Open AccessArticle

Perioperative Intravenous Lidocaine and Early Biochemical Outcomes After Robotic-Assisted Radical Prostatectomy: A Clinical Study Within the Framework of Perioperative Metabolic-Inflammatory Modulation

by Georgiana Maria Popa, Simona-Alina Abu-Awwad, Ahmed Abu-Awwad, Nicolae Ovidiu Pop, Parascovia Pop, Carmen Ioana Marta, Anca Mihaela Bina, Erika Bimbo Szuhai, Adriana Cacuci, Adrian Gheorghe Osiceanu, Ciprian Dumitru Puscas, Teodor Traian Maghiar and Mihai Octavian Botea

Metabolites 2026, 16(3), 209; https://doi.org/10.3390/metabo16030209 - 20 Mar 2026

Cited by 2 | Viewed by 760

Abstract

Background: The perioperative period in cancer surgery is characterized by transient metabolic and inflammatory perturbations that may influence early postoperative biochemical dynamics. Surgical stress induces insulin resistance, hyperglycemia, cytokine activation, and metabolic shifts that interact with tumor cell signaling pathways. Intravenous lidocaine has [...] Read more.

Background: The perioperative period in cancer surgery is characterized by transient metabolic and inflammatory perturbations that may influence early postoperative biochemical dynamics. Surgical stress induces insulin resistance, hyperglycemia, cytokine activation, and metabolic shifts that interact with tumor cell signaling pathways. Intravenous lidocaine has been associated with anti-inflammatory and systemic stabilizing effects beyond analgesia. We investigated whether perioperative lidocaine administration during robotic-assisted radical prostatectomy (RARP) is associated with early postoperative prostate-specific antigen (PSA) dynamics within the context of perioperative metabolic–inflammatory modulation. Methods: In this single-center retrospective cohort study, 180 patients undergoing RARP for localized or locally advanced prostate cancer were stratified according to perioperative intravenous lidocaine exposure. The primary endpoint was undetectable PSA (<0.1 ng/mL) at 6–12 weeks postoperatively. Secondary endpoints included PSA detectability at 3 and 6 months and time to first detectable PSA. Multivariable logistic and Cox regression models were adjusted for established oncologic risk factors. Perioperative glycemic variation, intraoperative lactate dynamics, and postoperative IL-6 levels were analyzed as indicators of stress-induced metabolic activation. Results: Lidocaine exposure was independently associated with higher odds of undetectable PSA at 6–12 weeks (OR 2.10, 95% CI 1.15–3.85) and at subsequent time points. In Cox analysis, lidocaine was associated with a reduced hazard of PSA detectability (HR 0.58, 95% CI 0.37–0.92). Patients receiving lidocaine demonstrated significantly attenuated perioperative hyperglycemia, lower lactate elevation, and reduced IL-6 response. Conclusions: Perioperative intravenous lidocaine administration during RARP was associated with more favorable early PSA dynamics and attenuation of perioperative metabolic–inflammatory activation. Given the retrospective and non-randomized design of the study, these findings should be interpreted as associative and hypothesis-generating, and warrant confirmation in prospective controlled investigations. Full article

(This article belongs to the Special Issue Metabolic Regulation in Cancer Development and Progression)

19 pages, 2455 KB

Open AccessArticle

Metformin Regulation of the Liver Circadian Clock and Metabolic Aging: A Systems Modeling Study

by Mengyuan Zhang and Ying Li

Metabolites 2026, 16(3), 208; https://doi.org/10.3390/metabo16030208 - 20 Mar 2026

Viewed by 1101

Abstract

Introduction: Aging affects both metabolic and circadian systems, leading to disruptions in energy homeostasis and phase shifts in the circadian clock. Metformin, a widely used antihyperglycemic drug, exerts anti-aging effects by modulating key pathways in the liver and also influences the liver circadian [...] Read more.

Introduction: Aging affects both metabolic and circadian systems, leading to disruptions in energy homeostasis and phase shifts in the circadian clock. Metformin, a widely used antihyperglycemic drug, exerts anti-aging effects by modulating key pathways in the liver and also influences the liver circadian clock. However, the optimal medication strategy, including dosage and timing, that achieves significant anti-aging effects while minimizing negative impacts on the circadian clock remains unclear. This study aims to identify a rational metformin administration strategy considering both aspects. Methods: An extended mathematical model of the liver circadian clock incorporating metformin regulation was developed, and numerical simulations were performed to evaluate different dosing times and feeding conditions. Results: Metformin administration at different times produced distinct effects on both the circadian clock and anti-aging outcomes. Administration during the increasing phase of CLOCK-BMAL1 concentration showed positive effects on the circadian clock and effective anti-aging properties. Regarding feeding patterns, a fed-like state was not conducive to anti-aging, whereas fasting was beneficial. Conclusions: These findings highlight the importance of dosing time and feeding styles in optimizing metformin efficacy and provide insights into its potential pharmacological applications in anti-aging therapy. Full article

(This article belongs to the Section Pharmacology and Drug Metabolism)

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34 pages, 2162 KB

Open AccessReview

Extracellular Vesicles Associated Metabolites as Intercellular Signalling Mediators in Disease and Therapy

by Abdul Qadeer, Abd Ullah, Muhammad Zahoor Khan, Khalaf F. Alsharif, Fuad M. Alzahrani, Khalid J. Alzahrani and Abdulwahab A. Abuderman

Metabolites 2026, 16(3), 207; https://doi.org/10.3390/metabo16030207 - 20 Mar 2026

Cited by 2 | Viewed by 2258

Abstract

Extracellular vesicles (EVs), particularly exosomes, have emerged as critical mediators of intercellular communication, yet the metabolite fraction of their cargo remains substantially underexplored relative to proteins and nucleic acids. This review synthesizes current knowledge on the exosomal metabolome as a functionally distinct intercellular [...] Read more.

Extracellular vesicles (EVs), particularly exosomes, have emerged as critical mediators of intercellular communication, yet the metabolite fraction of their cargo remains substantially underexplored relative to proteins and nucleic acids. This review synthesizes current knowledge on the exosomal metabolome as a functionally distinct intercellular signaling system with unique biophysical properties. We review the mechanisms proposed to govern metabolite encapsulation into exosomes, encompassing membrane transporter involvement, lipid raft partitioning, and binding to luminal proteins, and discuss the unresolved question of whether metabolite loading is selective or stochastic. Critically, we present a quantitative framework evaluating whether delivered metabolite quantities are sufficient to alter recipient cell metabolic pools, distinguishing receptor-mediated signaling from bulk substrate delivery. We also address methodological considerations including contamination artifacts and isolation-method biases that complicate interpretation of EV metabolomics data. Exosomal metabolites are reviewed across four functional categories: energy substrates (ATP, lactate, amino acids), signaling molecules (TCA cycle intermediates, eicosanoids, nucleotides), redox cofactors and antioxidants (NADH, glutathione), and oncometabolites. For each category, available evidence is critically appraised, distinguishing metabolites with direct mass spectrometric detection from those whose roles are inferred from parent-cell biology. The review examines the roles of exosomal metabolites in tumor-stroma metabolic symbiosis, immunometabolic regulation, inter-organ crosstalk in metabolic diseases including type 2 diabetes and non-alcoholic fatty liver disease, cancer metastasis, viral infections, and immune evasion. A quantitative framework is discussed to evaluate whether delivered metabolite quantities are sufficient to alter recipient cell metabolic pools, distinguishing receptor-mediated signaling from bulk substrate delivery. Technical challenges in exosomal metabolomics are reviewed, including the impact of isolation method on data quality, contamination artifacts, and current standardization gaps. Therapeutic implications of exosomal metabolite signaling are discussed, encompassing metabolite-loaded exosomes as therapeutic vehicles and exosomal metabolite loading as a pharmacological target. Integration of single-vesicle technologies with systems biology approaches is highlighted as a promising direction for advancing this field toward precision medicine applications in oncological and metabolic disorders. Full article

(This article belongs to the Special Issue The Molecular Cargo of Extracellular Vesicles: A Key to Understanding Their Biological Role)

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31 pages, 1380 KB

Open AccessReview

Decoding the Metabolic Signatures of Neurodegeneration Diseases: Advances in Mass Spectrometry-Based Metabolomics

by Md Abdul Hakim and Li Li

Metabolites 2026, 16(3), 206; https://doi.org/10.3390/metabo16030206 - 20 Mar 2026

Viewed by 2218

Abstract

The dysregulation of multiple metabolic pathways is a potential contributor to the development of neurodegenerative diseases. Understanding early-stage metabolic alterations is crucial for identifying targets associated with disease development and progression. Recent advances in mass spectrometry-based metabolomics now allow investigators to conduct a [...] Read more.

The dysregulation of multiple metabolic pathways is a potential contributor to the development of neurodegenerative diseases. Understanding early-stage metabolic alterations is crucial for identifying targets associated with disease development and progression. Recent advances in mass spectrometry-based metabolomics now allow investigators to conduct a comprehensive analysis of small-molecule metabolites in complex biological systems, providing valuable insights regarding the biochemical mechanisms underlying neurodegeneration. This review presents the latest advances in mass spectrometry-based metabolomic approaches and their applications in studying neurodegenerative diseases. We discuss methodology improvements in metabolomics, including sample preparation, chromatography separations, ionization, and fragmentation. These improvements enable broader detection and more accurate identification of metabolites. We also review developments in bioinformatics tools for large-scale data processing, structural annotation, and pathway analysis. Furthermore, the signature metabolites associated with major neurodegenerative diseases and the key metabolic pathways involved are summarized. Finally, we address current analytical and biological challenges in mass spectrometry-based metabolomics while exploring its future directions in translational research. Full article

(This article belongs to the Special Issue Metabolomic Fingerprinting: Challenges and Opportunities)

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22 pages, 2610 KB

Open AccessArticle

Remodeling of the Mouse Liver and Skeletal Muscle Metabolome in Response to Continuous Acute Exercise and Disruption of AMPK-Glycogen Interactions

by Mehdi R. Belhaj, David I. Broadhurst, Thomas Dignan, Jamie Whitfield, Lisa Murray-Segal, Naomi X. Y. Ling, Jonathan S. Oakhill, Bruce E. Kemp, John A. Hawley, Stacey N. Reinke and Nolan J. Hoffman

Metabolites 2026, 16(3), 205; https://doi.org/10.3390/metabo16030205 - 20 Mar 2026

Viewed by 1829

Abstract

Background/Objectives: Acute exercise remodels many interconnected biochemical pathways in metabolically active tissues. This remodeling involves the activation of the energy-sensing AMP-activated protein kinase (AMPK) to maintain cellular energy homeostasis. Critical energy reserves of glycogen, primarily stored in liver and skeletal muscle and [...] Read more.

Background/Objectives: Acute exercise remodels many interconnected biochemical pathways in metabolically active tissues. This remodeling involves the activation of the energy-sensing AMP-activated protein kinase (AMPK) to maintain cellular energy homeostasis. Critical energy reserves of glycogen, primarily stored in liver and skeletal muscle and known to interact with AMPK, are utilized to help meet increased energy demands with exercise. However, the breadth of metabolic pathways regulated by acute exercise and AMPK’s interactive roles with glycogen remain incompletely understood. This study therefore aimed to map mouse liver and skeletal muscle metabolite responses to continuous acute exercise and disruption of AMPK-glycogen interactions. Methods: Liquid chromatography–mass spectrometry-based untargeted metabolomics was used to measure the relative abundance of liver and gastrocnemius muscle metabolites at rest and following an acute bout of continuous treadmill running in wild type (WT) and AMPK transgenic mice with double knock-in (DKI) mutations in the β subunit carbohydrate binding module that mediates glycogen binding. Results: Over 200 total metabolites were identified/annotated across liver and skeletal muscle, including 45 metabolites responsive to exercise (p < 0.05; FDR < 0.1). Exercise-regulated metabolites included known metabolic pathways and metabolites never associated or with only emerging evidence related to exercise (e.g., ergothioneine) and/or AMPK-glycogen interactions (N6,N6,N6-trimethyl-L-lysine, a precursor of L-carnitine). Conclusions: Liver and skeletal muscle metabolomic profiles displayed shifts between WT and DKI mice at rest, with shifts also detected following a continuous acute exercise bout. An interaction effect was also observed in skeletal muscle, suggesting differential muscle metabolite responses to acute exercise in DKI mice that may contribute to their functional impairments in metabolic control and exercise capacity versus WT. Collectively, these findings expand the molecular landscape of acute exercise and reveal liver and muscle metabolites underlying exercise-induced metabolic responses. Full article

(This article belongs to the Special Issue Metabolic Responses to Exercise and Nutrition: From Molecular Mechanisms to Functional Performance)

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11 pages, 315 KB

Open AccessArticle

Validation of a Diabetes Subtype Classification Model Using Data from U.S. Adults Before and After the COVID-19 Pandemic

by Brian Lu, Peng Li, Andrew B. Crouse, Tiffany Grimes, Ava N. Smith, Matthew Might, Fernando Ovalle and Anath Shalev

Metabolites 2026, 16(3), 204; https://doi.org/10.3390/metabo16030204 - 19 Mar 2026

Viewed by 1111

Abstract

Background: We (and others) have previously identified five clinically distinct diabetes subtypes. Currently, few models to identify diabetes subtypes are readily accessible. Further, while COVID-19 has been associated with increased risk of new-onset diabetes, it remains unknown whether the pandemic is also associated [...] Read more.

Background: We (and others) have previously identified five clinically distinct diabetes subtypes. Currently, few models to identify diabetes subtypes are readily accessible. Further, while COVID-19 has been associated with increased risk of new-onset diabetes, it remains unknown whether the pandemic is also associated with changes in diabetes subtype distribution. Methods: We used the electronic health records of patients diagnosed with diabetes from 2010 to 2019 at the Kirklin Clinic of the University of Alabama at Birmingham (UAB) to train models to assign diabetes subtypes previously identified by hierarchical clustering. We then applied the trained model to conduct a retrospective cluster analysis of electronic health records of patients diagnosed with diabetes from 2020 to 2024 at UAB. We further validated our findings using data from the 2015–2023 National Health and Nutrition Examination Surveys (NHANES). Results: The trained classification model had an average specificity of 98% and an average sensitivity of 93%. Using the model, we identified a significant difference in the distribution of type 2 diabetes subtypes in patients at UAB and in participants in NHANES. In particular, the proportion of patients with severe insulin-dependent diabetes or severe insulin-resistant diabetes subtypes increased from 42% to 61% and 31% to 40% at the UAB and in NHANES, respectively. Conclusions: The model presented here can facilitate the identification of diabetes subtypes. The proportions of patients with severe subtypes of diabetes have seemed to increase in the more recent years following the pandemic. Further studies are required to determine the potential causes of this phenomenon. Full article

(This article belongs to the Special Issue Exploring Pathological Mechanisms in Obesity, Diabetes, and Metabolic Syndrome: 2nd Edition)

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13 pages, 636 KB

Open AccessArticle

Malondialdehyde as a Predictor of Disease Severity and Cardiovascular Risk in Population with Metabolic Dysfunction-Associated Steatotic Liver Disease

by Roberto Lugo, Ana Ligia Gutiérrez-Solis, Ricardo Emmanuel Jimeno-Figueroa, Paul Góngora-Chan, Mayra Vera-Aviles, Dayana Williams-Jacquez, Marlene Chaurand-Lara, Jorge Arturo Valdivieso-Jimenez, Isabel Medina-Vera, Martha Guevara-Cruz, Brenda Pacheco-Hernández, Noriyouky Ix-Ruiz, Rodolfo Chim-Aké and Azalia Avila-Nava

Metabolites 2026, 16(3), 203; https://doi.org/10.3390/metabo16030203 - 19 Mar 2026

Cited by 3 | Viewed by 1528

Abstract

Background/Objectives: Metabolic dysfunction-associated steatotic liver disease (MASLD) is characterized by excessive triglyceride accumulation in the liver, the presence of one or more cardiometabolic risk factors, and an absence of harmful alcohol intake. Oxidative stress plays a crucial role in the development and [...] Read more.

Background/Objectives: Metabolic dysfunction-associated steatotic liver disease (MASLD) is characterized by excessive triglyceride accumulation in the liver, the presence of one or more cardiometabolic risk factors, and an absence of harmful alcohol intake. Oxidative stress plays a crucial role in the development and severity of this disease, contributing to an increased cardiovascular risk (CVR). Malondialdehyde (MDA), an oxidative biomarker resulting from lipid peroxidation, is closely associated with metabolic dysfunction. This study aimed to evaluate the role of MDA as a predictor of steatosis severity and CVR. Methodology: An observational cross-sectional study was conducted in a population with MASLD with hepatic steatosis confirmed by ultrasonography and computed tomography. Subjects were classified according to severity of the hepatic steatosis as grade I or grade II-III. Nutritional, anthropometric, and serum biochemical parameters were measured. MDA levels were determined using a spectrophotometric method. The CVR was assessed using waist-to-hip ratio (WHR), triglycerides-glucose (TyG) index, lipid accumulation product (LAP), and atherogenic index of plasma (AIP). Receiver operating characteristic (ROC) curve analysis was performed to identify MDA cut-off value, followed by multivariable logistic regression to assess its association with severity of steatosis adjusted for body fat percentage. Results: A total of 50 patients were included (21 men and 29 women). An MDA cut-off value ≥ 0.13 nmol/mL was associated with higher severity (grade II–III vs. grade I) (OR = 5.0; 95% CI: 1.20–20.0; p = 0.022). Higher WHR values were found in subjects with grade I (p = 0.049), and elevated TyG index values were observed in patients with grade I-III (p = 0.042) both indicating increased CVR. Conclusions: Elevated MDA levels and higher body fat percentage were associated with higher degree of hepatic steatosis and increased CVR in the population from southeastern Mexico. Full article

(This article belongs to the Special Issue Metabolomics and Lipidomics in MASLD and Related Liver Disorders)

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15 pages, 845 KB

Open AccessArticle

Inflammatory Load Across Diabetes Duration: CRP and ESR Patterns and Their Metabolic Correlates

by Roxana Daniela Brata, Cosmin Mihai Vesa, Madalina Ioana Moisi, Timea Claudia Ghitea, Nicolae Ovidiu Pop and Carmen Pantis

Metabolites 2026, 16(3), 202; https://doi.org/10.3390/metabo16030202 - 19 Mar 2026

Cited by 2 | Viewed by 1400

Abstract

Background: Type 2 diabetes mellitus (T2DM) is characterized by chronic low-grade inflammation that contributes to cardiometabolic complications. While diabetes duration reflects cumulative metabolic exposure, its relationship with systemic inflammatory burden remains insufficiently defined. We aimed to investigate inflammatory patterns across diabetes duration and [...] Read more.

Background: Type 2 diabetes mellitus (T2DM) is characterized by chronic low-grade inflammation that contributes to cardiometabolic complications. While diabetes duration reflects cumulative metabolic exposure, its relationship with systemic inflammatory burden remains insufficiently defined. We aimed to investigate inflammatory patterns across diabetes duration and to explore their metabolic and cardio–renal correlates. Methods: This real-world cross-sectional study included 250 adults with T2DM. Diabetes duration was analyzed both continuously and across four predefined strata (0–4, 5–9, 10–14, and ≥15 years). Inflammatory burden was assessed using C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Given the skewed distribution of CRP, log-transformed CRP was used in regression analyses. Nonlinear associations were evaluated using quadratic regression models. This approach was selected because preliminary descriptive analyses suggested a non-monotonic relationship between diabetes duration and CRP levels. Inclusion of a quadratic term allowed formal testing of a potential curvilinear association between diabetes duration and inflammatory burden. Spearman correlations were performed to assess associations with metabolic, renal, and cardiovascular variables. Results: CRP showed a nonlinear cross-sectional association across diabetes duration strata. Median CRP values were higher in early (0–4 years: 0.62 mg/L) and long-standing diabetes (≥15 years: 0.77 mg/L) compared with intermediate-duration groups (p = 0.063). Quadratic regression confirmed a U-shaped relationship (adjusted β_duration = −0.079, p < 0.001; β_duration² = 0.0027, p < 0.001; R² = 0.326). ESR differed significantly across duration strata (p = 0.002), with the highest levels observed in long-standing diabetes. CRP correlated positively with BMI (ρ = 0.151; p = 0.017) and triglyceride-to-HDL ratio (ρ = 0.215; p < 0.001), but not with HbA1c. Both CRP and ESR were more strongly associated with functional CKD (ρ = 0.350 and 0.429, respectively; p < 0.001) than with ASCVD. Conclusions: Inflammatory burden in T2DM shows a nonlinear cross-sectional pattern across diabetes duration, characterized by elevated levels in early and long-standing disease. Systemic inflammation appears more closely linked to renal dysfunction than to established cardiovascular disease. These findings support a cardio–renal–inflammatory axis in which prolonged diabetes exposure contributes to renal decline, which in turn amplifies systemic inflammatory activation. Full article

(This article belongs to the Section Endocrinology and Clinical Metabolic Research)

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17 pages, 1963 KB

Open AccessEditor’s ChoiceArticle

Dietary Citrus Peel Supplementation Enhances Hepatic Energy Metabolism, Muscle 9-HODE Generation and Isoleucine Catabolism in Beef Cattle

by Susumu Muroya, Koichi Ojima, Arata Banno, Hirotaka Nagai, Kazumasa Kakibuchi, Takuma Higuchi, Shuji Sakamoto and Kazutsugu Matsukawa

Metabolites 2026, 16(3), 201; https://doi.org/10.3390/metabo16030201 - 18 Mar 2026

Viewed by 1644

Abstract

Background: Citrus components potentially suppress adipogenic differentiation and lipid accumulation, and exhibit anti-inflammatory and antioxidant effects. We hypothesized that the bioactive compounds in Citrus junos Sieb ex Tanaka (yuzu) fruit peel can alter the systemic metabolism and productivity of beef cattle. Methods: Japanese [...] Read more.

Background: Citrus components potentially suppress adipogenic differentiation and lipid accumulation, and exhibit anti-inflammatory and antioxidant effects. We hypothesized that the bioactive compounds in Citrus junos Sieb ex Tanaka (yuzu) fruit peel can alter the systemic metabolism and productivity of beef cattle. Methods: Japanese Brown (JBR) steers were fed with a diet supplemented with 2.5% yuzu peel during the last month of the finishing period. To investigate the effect of dietary yuzu supplementation (DYS) on beef and liver metabolism, we explored the metabolomic profiles of longissimus thoracis (LT, loin) muscle at 14 d postmortem using capillary electrophoresis (CE-TOF/MS) and high-performance liquid chromatography time-of-flight mass spectrometry (LC-TOF/MS). Results: The DYS treatment enhanced the beef fat score compared to that recorded in beef in the no-DYS (None) group (p = 0.050); however, the other carcass quality traits were not significantly different between the DYS and None groups. CE-TOF/MS and LC-TOF/MS revealed 242 and 107 annotated peaks, respectively, for the LT muscle. DYS significantly increased 9(S)-hydroxyoctadecadienoic acid (9-HODE, a beef flavor precursor), cyclo(-Leu-Pro), spermidine, asymmetric dimethylarginine, and 7α-hydroxycholesterol levels and reduced 2-ethylhydracrylic acid (2-EHAA), γ-tocopherol, coenzyme Q10 (CoQ10), sphingomyelin(d18:1/16:0), Cys-Gly, Tyr-Arg, and palmitoylcarnitine levels in postmortem LT muscle (p < 0.050). Concomitantly, in the fresh liver, DYS increased acetyl-CoA, 6-phosphogluconic acid, S-methylglutathione, ATP, ribulose 5-phosphate, and ADP levels and suppressed the content of thiamine, Ala-Ala, riboflavin, and ascorbate 2-sulfate (p < 0.050). Conclusion: Collectively, yuzu ingredients activated ATP production in the liver through the elevation of hepatic energy metabolism primarily in the citrate cycle and β-oxidation, and potentially altered muscle metabolism, including linoleic acid oxidation, FAD-mediated electron transport chain, and isoleucine catabolism, as demonstrated in the reduced accumulation of 2-EHAA and CoQ10 in DYS beef. Moreover, DYS likely affects the gut microbiome by enhancing the production of cyclo(-Leu-Pro), an antimicrobial dipeptide. Full article

(This article belongs to the Special Issue Muscle Metabolic Response and Adaptation to Exercise, Diet, and Environment: 2nd Edition)

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25 pages, 1198 KB

Open AccessReview

Metabolomic Profiling of Tyrosine Kinase Inhibitor-Induced Endothelial Dysfunction and Cardiovascular Toxicity

by Gurkaranvir Singh, Inderjeet Bharaj, Joey Bettencourt, Amarjit Kaur Sekhon, Gurparvesh Singh, Aaron Sidhu, Emanuel Zayas Diaz, Sulaiman Paika, Ariel De Leon, Ajit Brar, Gursimran Brar, Inderbir Padda and Ambar Andrade

Metabolites 2026, 16(3), 200; https://doi.org/10.3390/metabo16030200 - 17 Mar 2026

Viewed by 1705

Abstract

Background: Tyrosine kinase inhibitors (TKIs) have transformed cancer therapy; however, they are associated with cardiovascular toxicity. Metabolomics provides a comprehensive framework for identifying early biochemical disruptions that precede clinical manifestations and for formulating mechanism-based intervention strategies. Methods: We conducted a narrative synthesis of [...] Read more.

Background: Tyrosine kinase inhibitors (TKIs) have transformed cancer therapy; however, they are associated with cardiovascular toxicity. Metabolomics provides a comprehensive framework for identifying early biochemical disruptions that precede clinical manifestations and for formulating mechanism-based intervention strategies. Methods: We conducted a narrative synthesis of published preclinical and translational studies on TKI cardiotoxicity, focusing on untargeted and targeted metabolomic findings and complementary proteomic and transcriptomic data. Functional validation was performed using rodent and cellular models. Mechanistic themes were identified, and implications for biomarker panels, multi-omic integration, and metabolomics-guided interventions were proposed. Conclusions: Metabolomic analyses of various TKIs identified convergent signatures along three interconnected axes: (1) mitochondrial bioenergetic dysfunction characterized by impaired long-chain fatty acid oxidation and adenylate depletion; (2) disruption of endothelial nitric oxide signaling with redox imbalance, including increased nitrotyrosine, Nox activation, and eNOS uncoupling; and (3) an inflammatory metabolic profile marked by elevated branched-chain and aromatic amino acids, creatine, and osmolytes. Rodent models of sunitinib and sorafenib replicate these signatures and demonstrate histological injury, contractile dysfunction, and fibrosis. Preclinical intervention data, particularly restoration of myocardial carnitine, AMPK signaling, and fatty acid oxidation by L-carnitine, provide proof of concept for metabolomics-guided cardioprotection. Metabolomics can identify mechanistic biomarkers that facilitate the early detection, risk stratification, and targeted prevention of TKI-induced cardiovascular injury. Translation into precision cardio-oncology requires prospective validation, standardized assays, and biomarker-driven interventional trials. Full article

(This article belongs to the Section Endocrinology and Clinical Metabolic Research)

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20 pages, 1336 KB

Open AccessArticle

Longitudinal Plasma Metabolomics by GC–MS and LC–MS During Total Parenteral Nutrition After Gastrointestinal Surgery

by Duygu Konuklu, Cemil Can Eylem, İpek Baysal, Busenur Kırımtay, Emirhan Nemutlu, Timuçin Erol, Şermin Ataç and İncilay Süslü

Metabolites 2026, 16(3), 199; https://doi.org/10.3390/metabo16030199 - 16 Mar 2026

Cited by 1 | Viewed by 864

Abstract

Background: Total parenteral nutrition (TPN) is widely used after major gastrointestinal surgery; however, its early systemic metabolic effects and temporal adaptation patterns remain incompletely characterized. This study applied a longitudinal plasma metabolomics approach to investigate time-dependent metabolic changes during early TPN administration. Methods: [...] Read more.

Background: Total parenteral nutrition (TPN) is widely used after major gastrointestinal surgery; however, its early systemic metabolic effects and temporal adaptation patterns remain incompletely characterized. This study applied a longitudinal plasma metabolomics approach to investigate time-dependent metabolic changes during early TPN administration. Methods: Plasma samples were collected from patients undergoing gastrointestinal surgery before TPN initiation (baseline, T0) and at 24 h (T1), 48 h (T2), and 72 h (T3). Untargeted metabolomic profiling was performed using complementary gas chromatography–mass spectrometry (GC–MS) and liquid chromatography–mass spectrometry (LC–MS) platforms. In total, 111 metabolites were detected. Analysis of variance (ANOVA) with baseline (T0) as the reference identified time-point–specific metabolic alterations during TPN administration. Results: At 24 h (T1), nominally significant increases were observed in glycine, tryptophan, isoleucine, and methionine, accompanied by decreases in sarcosine and oxalic acid. At 48 h (T2), elevated levels of glycine, isoleucine, valine, and phenylalanine persisted, while sarcosine, oxalic acid, and myo-inositol remained decreased. By 72 h (T3), sustained increases in glycine, isoleucine, valine, phenylalanine, proline, alanine, and tryptophan were accompanied by reduced levels of sarcosine, oxalic acid, and glucopyranose, reflecting coordinated alterations across multiple metabolite classes. Conclusions: Overall, the results demonstrated a distinct longitudinal metabolomic pattern characterized by increases in circulating amino acids and time-dependent changes in carbohydrate- and lipid-related metabolites within the first 72 h of TPN. This exploratory, time-resolved metabolomic study in 37 patients highlights the utility of untargeted metabolomics for characterizing early metabolic adaptation to parenteral nutrition and supporting postoperative metabolic monitoring. Full article

(This article belongs to the Section Endocrinology and Clinical Metabolic Research)

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14 pages, 1570 KB

Open AccessArticle

Lifestyle Intervention Therapy Modulates Global DNA Methylation and Adipogenic Gene Expression in Severely Obese Hypogonadal Men

by Siresha Bathina, Virginia Fuenmayor Lopez, Mia Prado, Salina Biene Teo, Dennis T. Villareal, Rui Chen, Clifford Qualls and Reina Armamento-Villareal

Metabolites 2026, 16(3), 198; https://doi.org/10.3390/metabo16030198 - 16 Mar 2026

Viewed by 2044

Abstract

Background/Objectives: Previous studies have suggested that lifestyle intervention (LSI) therapies involving diet and exercise can modulate DNA methylation; however, whether this occurs in severely obese hypogonadal men undergoing weight loss from diet and exercise remains unclear. Methods: In this study, we investigated the [...] Read more.

Background/Objectives: Previous studies have suggested that lifestyle intervention (LSI) therapies involving diet and exercise can modulate DNA methylation; however, whether this occurs in severely obese hypogonadal men undergoing weight loss from diet and exercise remains unclear. Methods: In this study, we investigated the effects of weight loss from diet and exercise on global DNA methylation as well as on the mRNA expression of specific demethylation enzymes, DNMT1, DNMT3A, and DNMT3B—in peripheral blood mononuclear cells (PBMCs) and DNA methylation markers in DNA of severely obese hypogonadal men. This is a secondary analysis of samples of severely obese (body mass index of ≥35 kg/m²) hypogonadal men undergoing weight loss from diet and exercise in addition to an aromatase inhibitor (anastrozole) or placebo for a total of 12 months. Results: LSI therapy significantly reduced global DNA methylation and 5-methylcytosine (5-mC) levels, decreased DNMT1, DNMT3A, and DNMT3B (p < 0.05) mRNA levels and markedly decreased CEBPα, FTO, and PPARγ mRNA expression. The reduction in global methylation was independent of aromatase inhibitor use. Conclusions: In summary, our findings suggest that LSI induces epigenetic modifications in leukocytes, possibly through the regulation of DNMT gene expression. Future studies are warranted to clarify the mechanistic pathways linking lifestyle-induced epigenetic alterations to metabolic health outcomes. Full article

(This article belongs to the Special Issue Interactions Between Exercise Physiology and Metabolism)

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15 pages, 972 KB

Open AccessArticle

HbA1c as a Continuous Marker of Microvascular Vulnerability: Development of a Non-Linear Risk Framework in a Real-World Cohort

by Mihaela Simona Popoviciu, Alina Manuela Pop, Timea Claudia Ghitea, Florica Ramona Dorobantu, Carmen Pantis, Nicolae Ovidiu Pop and Roxana Daniela Brata

Metabolites 2026, 16(3), 197; https://doi.org/10.3390/metabo16030197 - 16 Mar 2026

Cited by 2 | Viewed by 1227

Abstract

Background: Glycated hemoglobin (HbA1c) is widely used for the diagnosis and monitoring of diabetes mellitus; however, its interpretation is largely based on fixed diagnostic thresholds. This study moves beyond describing a glycemic continuum by translating the non-linear HbA1c–microvascular relationship into an individualized risk [...] Read more.

Background: Glycated hemoglobin (HbA1c) is widely used for the diagnosis and monitoring of diabetes mellitus; however, its interpretation is largely based on fixed diagnostic thresholds. This study moves beyond describing a glycemic continuum by translating the non-linear HbA1c–microvascular relationship into an individualized risk estimation framework. Methods: In this cross-sectional observational study, adult subjects from a real-world clinical cohort were analyzed using HbA1c as a continuous variable. Associations between HbA1c and metabolic parameters were assessed using correlation analysis. Linear regression was applied to evaluate the relationship between HbA1c and cumulative diabetes-related complication burden. Non-linear associations between HbA1c and the risk of presenting at least one complication were explored using restricted cubic spline logistic regression models. Additional risk estimation analyses focused on the HbA1c gray zone (5.5–6.4%). Results: HbA1c showed a strong continuous association with fasting plasma glucose (ρ = 0.73, p < 0.001) and was positively associated with cumulative complication burden (β = 0.016 per 1% increase in HbA1c, p = 0.009). Non-linear modeling revealed a progressive increase in complication risk beginning below the diagnostic threshold for diabetes, with an inflection of the risk curve within the HbA1c gray zone. Individuals within this interval exhibited a higher prevalence and increased odds of presenting at least one complication compared with lower HbA1c values, although some estimates did not reach statistical significance. Conclusions: HbA1c acts as a continuous and non-linear marker of metabolic stress, with potentially biologically meaningful increases in complication risk emerging below traditional diagnostic thresholds. We demonstrate a non-linear acceleration of microvascular risk within the 5.5–6.4% interval, rather than a simple linear gradient. These findings support the concept of a glycemic risk continuum and highlight the clinical relevance of the HbA1c sub-diagnostic interval for early risk stratification and preventive strategies. Full article

(This article belongs to the Section Endocrinology and Clinical Metabolic Research)

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15 pages, 486 KB

Open AccessReview

Exercise Reprograms the Spatial Function of Phosphoglycerate Dehydrogenase of a Pathogenic Nuclear Transcription Factor (PHGDH): A Narrative Review

by Dong Yang, Wen Guo and Liang Guo

Metabolites 2026, 16(3), 196; https://doi.org/10.3390/metabo16030196 - 16 Mar 2026

Viewed by 996

Abstract

Background: Alzheimer’s disease (AD) represents a significant therapeutic challenge, largely attributed to the complex interplay of genetic and non-genetic mechanisms. Among the latter, metabolic dysregulation has emerged as a critical factor influencing disease progression. This study proposes a paradigm shift in our understanding [...] Read more.

Background: Alzheimer’s disease (AD) represents a significant therapeutic challenge, largely attributed to the complex interplay of genetic and non-genetic mechanisms. Among the latter, metabolic dysregulation has emerged as a critical factor influencing disease progression. This study proposes a paradigm shift in our understanding of the role of phosphoglycerate dehydrogenase (PHGDH), a key metabolic enzyme, which, under pathological conditions associated with AD, transitions from a protective role to a pathogenic influence through alterations in its cellular localization and function. Methods: To elucidate the impact of exercise on PHGDH dynamics, a narrative review methodology was employed. We conducted comprehensive searches across bibliographic databases, including PubMed, Scopus, and Web of Science, focusing on peer-reviewed articles that detail the relationship between exercise, PHGDH activity, and AD-related neuroinflammation. The review was structured around specific inclusion criteria, which prioritized studies elucidating the mechanisms underlying PHGDH’s dual role in AD pathology and the influence of exercise on this process. Results: Our findings reveal that under AD-associated stress, PHGDH translocates to the nucleus, facilitating the activation of pro-inflammatory genes such as IKKα and HMGB1, while simultaneously suppressing autophagy and enhancing amyloid beta (Aβ) deposition. However, exercise induces the release of the myokine irisin, which inhibits PHGDH nuclear translocation through AMPK/PGC-1α signaling pathways. Additionally, peripheral effects of exercise are observed in hepatic Kupffer cells, where exercise attenuates PHGDH activity, leading to reduced systemic IL-1β release and neuroinflammation. Conclusions: This study underscores the potential of exercise as a precision intervention in AD management, highlighting its capacity to modulate PHGDH activity and mitigate neuroinflammatory processes. The therapeutic implications of these findings are profound, paving the way for novel diagnostic tools, such as PET probes for assessing PHGDH compartmentalization, and promoting a synergistic approach to “exercise–pharmacotherapy” in the treatment of Alzheimer’s disease. Future research should aim to further delineate the mechanisms by which exercise influences metabolic pathways in the context of neurodegeneration. Full article

(This article belongs to the Section Endocrinology and Clinical Metabolic Research)

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22 pages, 723 KB

Open AccessReview

NHE1-Mediated Metabolic Reprogramming in Cancer

by Majd A. Al-Hamaly, Beau R. Forester and Jessica S. Blackburn

Metabolites 2026, 16(3), 195; https://doi.org/10.3390/metabo16030195 - 15 Mar 2026

Cited by 1 | Viewed by 2114

Abstract

The sodium–hydrogen exchanger-1 (NHE1) is a ubiquitously expressed transmembrane transporter that plays a central role in maintaining intracellular pH homeostasis and supporting normal cellular function. In cancer, NHE1 is overexpressed in many tumor types and has been associated with increased cancer cell metastasis [...] Read more.

The sodium–hydrogen exchanger-1 (NHE1) is a ubiquitously expressed transmembrane transporter that plays a central role in maintaining intracellular pH homeostasis and supporting normal cellular function. In cancer, NHE1 is overexpressed in many tumor types and has been associated with increased cancer cell metastasis and proliferation. Beyond these established roles, emerging evidence implicates NHE1 as a regulator of cancer cell metabolism. By driving intracellular alkalinization and shaping the tumor microenvironment, NHE1 influences metabolic pathway activity, mitochondrial function, redox balance, and cellular stress responses. In this review, we synthesize current evidence linking NHE1 dysregulation to metabolic reprogramming in cancer, with a focus on mitochondrial metabolism, glycolytic flux, lysosomal biology, and reactive oxygen species-associated stress pathways. We further evaluate pharmacological strategies targeting NHE1, emphasizing their metabolic consequences, translational potential, and the challenges that have limited clinical application to date. Collectively, this review highlights NHE1 as a potential integrator of ion transport and metabolic control in cancer and discusses how targeting NHE1-driven metabolic programs may support the development of novel therapeutic strategies. Full article

(This article belongs to the Special Issue Metabolic Reprogramming in Cancer: New Frontiers for Therapeutic Intervention)

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13 pages, 753 KB

Open AccessArticle

Glycated High-Density Lipoproteins Reduce Endothelial Phenotypic Expression of Monocyte-Derived Multipotential Cells in Early Type 2 Diabetes

by Felipe Massó-Rojas, Luis Felipe Montaño-Estrada, Araceli Páez-Arenas, Juan Gabriel Juárez-Rojas, Aida Medina-Urrutia, Rafael Nambo-Venegas, Emma Rodríguez-Maldonado and Esteban Jorge-Galarza

Metabolites 2026, 16(3), 194; https://doi.org/10.3390/metabo16030194 - 15 Mar 2026

Viewed by 707

Abstract

Background: High-density lipoproteins (HDL) exert protective effects on the endothelium, which are impaired in type 2 diabetes (T2D). Although monocyte-derived multipotential cells (MOMCs) can be differentiated into the endothelial lineage, it remains unclear whether HDL glycation, size, and composition could affect MOMCs [...] Read more.

Background: High-density lipoproteins (HDL) exert protective effects on the endothelium, which are impaired in type 2 diabetes (T2D). Although monocyte-derived multipotential cells (MOMCs) can be differentiated into the endothelial lineage, it remains unclear whether HDL glycation, size, and composition could affect MOMCs differentiation. Methods: Twenty normoglycemic (49 years, 35% male), 20 prediabetic (52 years, 35% male), and 20 newly diagnosed T2D participants (51 years, 50% male) were recruited. HDL were isolated from each study group. The size, composition, and early, intermediate, or advanced glycation products of HDL were determined. CD14+ MOMCs were isolated from healthy volunteers and incubated with HDL from each group. Endothelial phenotypic expression was assessed by CD14⁺/KDR⁺ expression. Results: Compared with normoglycemic and prediabetic individuals, T2D patients had higher concentrations of early (4.4, 4.6, vs. 5.2 µmol/mg of protein, respectively; p = 0.049) and advanced (7.7, 8.7, vs. 14.3 µg-BSA-AGEs/mg of protein, respectively; p < 0.02) glycation products in HDL. HDL composition was similar among groups. The CD14+/KDR+ expression in MOMCs incubated with HDL from T2D patients was lower than that observed in prediabetes and normoglycemic individuals (46% vs. 52% and 61%, respectively; p = 0.002). Advanced glycation end products in HDL inversely correlated with CD14+/KDR+ cells (r = −0.418, p = 0.002), adjusting for other HDL characteristics. Conclusions: In T2D patients, increased HDL-advanced glycation impairs the endothelial phenotypic expression of MOMCs, independently of other HDL characteristics. Since advanced glycation leads to greater biological damage, these findings highlight the importance of preserving HDL integrity in T2D patients to support endothelial repair and potentially delay vascular complications. Full article

(This article belongs to the Special Issue Role of Lipid Metabolism in Cardiovascular Health)

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15 pages, 3173 KB

Open AccessArticle

Functional Analysis of GbFLS1045 Regulating the Metabolism of Flavonoids in Ginkgo biloba L.

by Xiaojing Kang, Xuefei Xu, Dan Liu, Yizeng Lu, Chenliang Zhao and Limin Sun

Metabolites 2026, 16(3), 193; https://doi.org/10.3390/metabo16030193 - 13 Mar 2026

Viewed by 877

Abstract

Objectives: Flavonoids are a class of widely distributed secondary metabolites in plants. Ginkgo biloba leaves are rich in flavonoids and thus are utilized for extracting medicinal components to treat and prevent cardiovascular and cerebrovascular diseases. Flavonol synthase (FLS) serves as a key [...] Read more.

Objectives: Flavonoids are a class of widely distributed secondary metabolites in plants. Ginkgo biloba leaves are rich in flavonoids and thus are utilized for extracting medicinal components to treat and prevent cardiovascular and cerebrovascular diseases. Flavonol synthase (FLS) serves as a key enzyme in the flavonol metabolic pathway. Numerous studies have identified and characterized FLS family genes across various plant species, all of which play crucial roles in regulating the flavonoid biosynthetic pathway. Methods: We measured the flavonoid content in Ginkgo biloba leaves across different months, performed transcriptomic analysis on leaves from months showing an increasing trend, and screened out the GbFLS1045 gene involved in the synthesis of the FLS enzyme. Molecular biology techniques were then employed to explore the function of the GbFLS1045 gene. Results: From June to August, the flavonoid content in Ginkgo biloba leaves exhibited an upward trend, and we found that GbFLS1045 is localized in the cytoplasm, cell membrane, and nucleus through transient transformation in Nicotiana tabacum. Overexpression(OE) of GbFLS1045 in Arabidopsis thaliana resulted in significantly higher levels of total flavonol glycosides, kaempferol, quercetin, and isorhamnetin in OE transgenic plants compared to WT controls. Furthermore, in OE lines of Ginkgo biloba callus, the isorhamnetin content was consistently elevated relative to both WT and Anti lines. Conclusions: GbFLS1045 positively regulates flavonoid synthesis in Ginkgo biloba. Full article

(This article belongs to the Section Plant Metabolism)

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5 pages, 406 KB

Open AccessEditorial

Metabolomics in Motion: Translating Molecular Signatures into Clinical Impact

by Dimitris Kounatidis and Iordanis Mourouzis

Metabolites 2026, 16(3), 192; https://doi.org/10.3390/metabo16030192 - 12 Mar 2026

Viewed by 510

Abstract

Metabolomics, the comprehensive and quantitative analysis of small-molecule metabolites, is a rapidly advancing and expanding field within contemporary systems biology [...] Full article

(This article belongs to the Special Issue Metabolomics in Human Diseases and Health)

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20 pages, 4863 KB

Open AccessArticle

The Phenylpropanoid Pathway Is a Central Roundabout in Peach Fruit Pre- and Postharvest Physiology

by Lorena Melet, Ricardo Nilo-Poyanco, Maria Paz Covarrubias, Reinaldo Campos-Vargas, María Luisa Valenzuela and Andrea Miyasaka Almeida

Metabolites 2026, 16(3), 191; https://doi.org/10.3390/metabo16030191 - 12 Mar 2026

Cited by 1 | Viewed by 1154

Abstract

Background: Peach fruit quality can be compromised by cold storage, a postharvest practice required for long-distance export that can trigger chilling injury and metabolic disturbances affecting sugars, organic acids, and other metabolites. Preharvest practices such as thinning modify source–sink relationships and fruit development, [...] Read more.

Background: Peach fruit quality can be compromised by cold storage, a postharvest practice required for long-distance export that can trigger chilling injury and metabolic disturbances affecting sugars, organic acids, and other metabolites. Preharvest practices such as thinning modify source–sink relationships and fruit development, potentially influencing susceptibility to chilling stress. Objectives: This study aimed to determine whether commercial thinning alters fruit susceptibility to cold storage damage and to identify metabolic processes associated with chilling tolerance in two nectarine varieties with contrasting sensitivity, ‘Magique’ (tolerant) and ‘Red Pearl’ (sensitive). Methods: Fruits from thinned (TH) and unthinned (UTH) trees were subjected to cold storage (0 °C, 21 days) followed by ripening, and evaluated for physiological parameters, sugar and organic acid composition by HPLC, and phenylpropanoid-related metabolites by ¹H-NMR. A genome-scale metabolic model was built to model fruit metabolism using COBRApy. Results: Thinning increased fruit size in both varieties. Magique exhibited overall metabolic stability across thinning treatments and cold storage. Red Pearl, in contrast, showed broad metabolic fluctuation in response to external stimuli. Integration of transcriptomic data and metabolic modeling identified quinate-centered reactions as candidate regulatory nodes associated with phenylpropanoid flux during ripening and post-chilling recovery. Conclusions: These findings indicate that modulating quinate metabolism during early ripening may help improve chilling tolerance and highlight the phenylpropanoid pathway as a central metabolic axis modulated by both pre- and postharvest practices, with implications for fruit quality management. Full article

(This article belongs to the Special Issue Metabolic Changes During Pre- and Post-Harvest Fruit and Vegetable Decay, Ripening and Senescence—2nd Edition)

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15 pages, 4841 KB

Open AccessArticle

Serum Semaphorin Alterations in Psoriasis: Links to Metabolic Status Rather than Disease Severity

by Anna Baran, Anna Stepaniuk, Justyna Magdalena Hermanowicz, Beata Sieklucka, Krystyna Pawlak, Dariusz Pawlak and Iwona Flisiak

Metabolites 2026, 16(3), 190; https://doi.org/10.3390/metabo16030190 - 12 Mar 2026

Viewed by 1072

Abstract

Introduction: Psoriasis is an autoimmune systemic disease of not entirely understood pathogenesis. It remains a significant therapeutic challenge and, due to its various comorbidities, has a remarkable detrimental effect on patients’ wellbeing. Semaphorins (Sema) are a group of transmembrane, cell surface-attached and secretory [...] Read more.

Introduction: Psoriasis is an autoimmune systemic disease of not entirely understood pathogenesis. It remains a significant therapeutic challenge and, due to its various comorbidities, has a remarkable detrimental effect on patients’ wellbeing. Semaphorins (Sema) are a group of transmembrane, cell surface-attached and secretory proteins that might play an important role in psoriasis due to their presence on keratinocytes and the ability to stimulate the proinflammatory cytokine production. Aims: The study aimed to assess the concentration of Sema3A, Sema3E, Sema4A, Sema4D and Sema7A in serum samples of psoriatic patients and explore the correlation with disease activity and clinical and metabolic status. Materials and Methods: The study involved 60 patients with plaque psoriasis and 30 healthy volunteers matched for gender, age, and BMI. Results: The mean serum Sema3A, Sema3E and Sema4D levels were significantly higher in patients with psoriasis than controls (p < 0.01, p < 0.05 and p < 0.05, respectively). Contrarily, Sema4A and Sema7A were significantly lower (p < 0.001 and p < 0.05 respectively). Significant positive correlation between Sema3A and UREA was noted. Sema3A levels were significantly higher in moderately ill and overweight patients (p < 0.05, p < 0.01, respectively) and in patients with longer-lasting psoriasis and male patients compared to controls (both p < 0.05). Sema3E significantly negatively correlated with HDL and glucose levels. Sema4A was significantly lower in moderately and severe psoriatic patients (p < 0.0001, p < 0.01, respectively). Sema7A was significantly higher in moderately ill and overweight patients (p < 0.05, p < 0.01, respectively) and significantly lower in male patients and in those with longer lasting disease than in controls. None of the semaphorins correlated with psoriasis severity, total BMI, psoriasis duration and age. Conclusions: Psoriatic patients exhibited distinct alterations in circulating semaphorins, with significantly increased serum Sema3A, Sema3E and Sema4D, and reduced Sema4A and Sema7A compared with healthy subjects. Selected semaphorins demonstrated associations with metabolic parameters and patient characteristics, although none can serve as marker of disease severity. The findings indicate that semaphorins may reflect psoriasis-related systemic disturbances, but further studies are required to explore their potential with disease-associated metabolic or clinical profiles. Full article

(This article belongs to the Special Issue Psoriasis and Metabolic Syndrome)

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18 pages, 1490 KB

Open AccessReview

Physiological Functions of Side-Chain-Retaining Sterols in the Brain and Their Roles in Neurodegenerative Diseases

by Yoshimitsu Kiriyama, Akira Nakatsuma, Hiroshi Tokumaru, Hisayo Sadamoto and Hiromi Nochi

Metabolites 2026, 16(3), 189; https://doi.org/10.3390/metabo16030189 - 11 Mar 2026

Viewed by 1450

Abstract

Although the brain comprises only 2% of total body weight, it contains approximately 23% of the total cholesterol of the body. In the brain, cholesterol plays a critical role as a structural component of cell membranes and myelin sheaths. However, the blood–brain barrier [...] Read more.

Although the brain comprises only 2% of total body weight, it contains approximately 23% of the total cholesterol of the body. In the brain, cholesterol plays a critical role as a structural component of cell membranes and myelin sheaths. However, the blood–brain barrier restricts cholesterol influx from the systemic circulation into the brain. As a result, the brain synthesizes cholesterol de novo and regulates its metabolism independently. Desmosterol, a cholesterol precursor produced during cholesterol biosynthesis, and cholesterol metabolites, 24S-hydroxycholesterol and chenodeoxycholic acid, are sterols with structurally retained side chains. These side-chain-retaining sterols have traditionally been regarded as intermediates in the cholesterol synthesis process or as metabolites for cholesterol excretion, but accumulating evidence indicates that they also function as physiologically active signaling molecules that influence brain function via nuclear receptors, such as liver X receptors, and membrane receptors, such as NMDA receptors. Through nuclear receptors, these side-chain-retaining sterols regulate the transcription of genes involved in lipid transport, inflammation control, and amyloid clearance, while their membrane receptor action enables rapid synaptic effects. These side-chain-retaining sterols mediate metabolic crosstalk between neurons and glial cells and contribute to maintaining cholesterol balance in the developing brain. Furthermore, these side-chain-retaining sterols have been shown to affect amyloid-β clearance, α-synuclein aggregation, neuroinflammation, mitochondrial function, and remyelination. Dysregulation of these side-chain-retaining sterols is associated with neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease. Overall, side-chain-retaining sterols are important regulators of brain physiology. This review focuses on the current knowledge regarding the physiological functions of side-chain-retaining sterols in the brain and their roles in neurodegenerative diseases. Full article

(This article belongs to the Special Issue Metabolomics in Neurodegenerative Diseases, 2nd Edition)

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3 pages, 176 KB

Open AccessCorrection

Correction: Ortolano et al. Enzymatic Evolution and Longitudinal Recovery in Biotinidase Deficiency: Genotypic and Clinical Insights from the Follow-Up of a Newborn-Screened Cohort in Emilia-Romagna, Italy. Metabolites 2025, 15, 605

by Rita Ortolano, Soara Menabò, Egidio Candela, Giacomo Biasucci, Elisa Bortolamedi, Giulia Montanari, Alessandro Zuccotti, Umberto Cattini, Marcello Lanari and Federico Baronio

Metabolites 2026, 16(3), 188; https://doi.org/10.3390/metabo16030188 - 11 Mar 2026

Viewed by 842

Abstract

The authors would like to make the following correction to their published paper [...] Full article

(This article belongs to the Section Endocrinology and Clinical Metabolic Research)

13 pages, 2566 KB

Open AccessArticle

The Effects of Adding Walnut Green Husk on the Quality of Alfalfa Mixed Silage, Protein Degradation, Microbial Community, and Their Interrelationships

by Naibi Abulaiti, Gulinigaer Aiyisirehong and Aibibula Yimamu

Metabolites 2026, 16(3), 187; https://doi.org/10.3390/metabo16030187 - 11 Mar 2026

Cited by 1 | Viewed by 690

Abstract

Objectives: This experiment was conducted to investigate the effects of adding walnut (Juglans regia L.) green husk (WGH) on the quality of alfalfa mixed silage, protein degradation, microbial community, and their interrelationships. Methods: Alfalfa (Medicago sativa L.) fresh grass [...] Read more.

Objectives: This experiment was conducted to investigate the effects of adding walnut (Juglans regia L.) green husk (WGH) on the quality of alfalfa mixed silage, protein degradation, microbial community, and their interrelationships. Methods: Alfalfa (Medicago sativa L.) fresh grass and WGH dried powder were used as raw materials to prepare three mixed silages of alfalfa fresh grass with 80 g/kg (A1), 120 g/kg (A2), and 160 g/kg (A3) of WGH dried powder, respectively, with alfalfa fresh grass silage as the control group (CK). After 60 days of ensilage, samples were taken and analyzed, with three replicates per treatment. Results: WGH treatment significantly improved alfalfa silage fermentation and nutritional quality. It reduced undesirable fermentation products while promoting beneficial lactic acid bacteria and preventing mold growth. Increasing the WGH ratio enhanced dry matter content and digestibility, with only a minor effect on crude protein. These results suggest that WGH is an effective silage additive for improving both fermentation characteristics and feed value. With the increase in the proportion of WGH, the proportions of rapidly degradable protein (PB1) and medium rate degradable protein (PB2) increased linearly, while the proportions of free amino acid nitrogen (FAA-N), peptide nitrogen (Peptide-N), slow degradable protein (PB3) and binding protein (PC) decreased linearly and the protease activity decreased significantly (p < 0.05). Bacterial community analysis showed that the relative abundance of Lactiplantibacillus and Levilactobacillus in the silage increased after WGH was added, while the relative abundance of Acetobacter, Pantoea, Weissella and Serratia decreased. Conclusions: Compared with pure alfalfa silage, the addition of WGH has a positive effect on silage quality, protein degradation and bacterial community structure, and the addition of WGH with 120 g/kg is more suitable. Full article

(This article belongs to the Section Nutrition and Metabolism)

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Open AccessCorrection

Correction: Liu et al. Metabolite Profile and Metabolic Network Analysis of Walnuts (Juglans regia L.) in Response to Chilling Stress. Metabolites 2025, 15, 394

by Kai Liu, Yang Li, Yaxin Sang, Yaru Zhang, Xiuhong An, Hongxia Wang and Ruifen Zhang

Metabolites 2026, 16(3), 186; https://doi.org/10.3390/metabo16030186 - 10 Mar 2026

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Abstract

The authors would like to make the following correction to their published paper [...] Full article

18 pages, 829 KB

Open AccessEditor’s ChoiceReview

Nexus of IDO1/Kynurenine Pathway to T-Cell Exhaustion: Hypoxia-Induced Tryptophan Metabolism in Glioblastoma

by Matthew Abikenari, George Nageeb, Joseph H. Ha, Matthew Adam Sjoholm, Justin Liu, Brandon Bergsneider, Jocelyn Valenzuela, James Poe, Kwang Bog Cho, Rohit Verma, Caren Wu, Vivek Sanker, Ravi Medikonda, Lily H. Kim, John Choi, Matei A. Banu and Michael Lim

Metabolites 2026, 16(3), 185; https://doi.org/10.3390/metabo16030185 - 10 Mar 2026

Cited by 7 | Viewed by 3205

Abstract

Glioblastoma (GBM) is a universally fatal cancer for which the standard of care has remained largely unchanged for the last 20 years. Recent work has demonstrated that most therapeutic trials for GBM fail due to complex mechanisms of immunosuppression mediated by both the [...] Read more.

Glioblastoma (GBM) is a universally fatal cancer for which the standard of care has remained largely unchanged for the last 20 years. Recent work has demonstrated that most therapeutic trials for GBM fail due to complex mechanisms of immunosuppression mediated by both the innate and adaptive immune systems. Various metabolic alterations in the tumor microenvironment help maintain this local and systemic immunosuppression, of which the axis of hypoxia-driven tryptophan degradation has garnered substantial attention over the last decade. This paper synthesizes a much-needed elucidation of the immunometabolic reshaping of glioma, myeloid, endothelial, and lymphoid cell lineages induced by hypoxia. The current paper critically evaluates the role of IDO1/TDO2-mediated breakdown of tryptophan and the consequent accumulation of kynurenine, a metabolite that triggers GCN2- and AHR-mediated CD8+ T-cell exhaustion and supports regulatory T-cell differentiation and expansion. Furthermore, we propose a synthesis of mechanistic evidence that establishes a role for the Trp-GCN2-ATF4-VEGFA axis in hypoxia-induced immunosuppression, supporting that pro-tumoral metabolic dysregulation is directly linked to angiogenesis. In GBM, hypoxia and tryptophan–kynurenine pathway dysregulation operate as an integrated metabolic circuit that drives widespread immunosuppression. These mechanisms can be captured by a metabolic signature shared across nearly every cell type in the GBM microenvironment. Drawing on recent spatial transcriptomic, metabolomic, and pharmacologic studies, we outline how this metabolic axis shapes disease biology and how it can be targeted to restore effective antitumor immunity. Full article

(This article belongs to the Special Issue Mechanistic Insights into Metabolic Interactions with the Tumor Microenvironment)

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Metabolites, Volume 16, Issue 3 (March 2026) – 67 articles

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