L-Carnitine and Acylcarnitines: Mitochondrial Biomarkers for Precision Medicine

Diagnosis of preeclampsia using metabolomic biomarkers

The diagnostic criteria for preeclampsia do not accurately reflect the pathophysiological characteristics of patients with preeclampsia. Conventional biomarkers and diagnostic approaches have proven insufficient to fully comprehend the intricacies of preeclampsia. This study aimed to screen differentially abundant metabolites as candidate biomarkers for preeclampsia. A propensity score matching method was used to perform a 1:1 match between preeclampsia patients (n = 70) and healthy control individuals (n = 70). Based on univariate and multivariate statistical analysis methods, the different characteristic metabolites were screened and identified. Least absolute shrinkage and selection operator (LASSO) regression analysis was subsequently used to further screen for differentially abundant metabolites. A receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic efficacy of the metabolites. A total of 1,630 metabolites were identified and quantified in maternal serum samples. Fifty-three metabolites were significantly increased, and two were significantly decreased in preeclampsia patients. The area under the curve (AUC) of the model composed of isobutyryl-L-carnitine and acetyl-leucine was 0.878, and the sensitivity and specificity in detecting preeclampsia were 81.4% and 87.1%, respectively. There are significant differences in metabolism between preeclampsia patients and healthy pregnant women, and a range of novel biomarkers have been identified. These findings lay the foundation for the use of metabolomic biomarkers for the diagnosis of preeclampsia.

Serum concentrations of lipids, ketones and acylcarnitines during the postprandial and fasting state: the Postprandial Metabolism (PoMet) study in healthy young adults

To improve the interpretation and utilisation of blood lipids, ketones and acylcarnitine concentrations as biomarkers in clinical assessments, more information is needed on their dynamic alterations in response to dietary intake and fasting. The aim of this intervention study was to characterise the changes in serum lipid, ketone and acylcarnitine concentrations 24 h after a standardised breakfast meal. Thirty-four healthy subjects (eighteen males and sixteen females) aged 20-30 years were served a breakfast meal (∼500 kcal, 36 E% fat, 46 E% carbohydrates, 16 E% protein, 2E% fibre), after which they consumed only water for 24 h. Blood samples were drawn before and at thirteen standardised timepoints after the meal. Metabolite concentrations were plotted as a function of time since the completion of the breakfast meal. Results demonstrated that concentrations of HDL-cholesterol and LDL-cholesterol decreased until ∼2 h (-4 % for both), while TAG concentrations peaked at 3 h (+27 %). Acetoacetate and β-hydroxybutyrate were highest 24 h after the meal (+433 and +633 %, respectively). Acetylcarnitine, butyrylcarnitine, hexanoylcarnitine, octanoylcarnitine, decanoylcarnitine and dodecanoylcarnitine reached the lowest values at 60 min (decreases ranging from -47 to -70 %), before increasing and peaking at 24 h after the meal (increases ranging from +86 to +120 %). Our findings suggest that distinguishing between fasting and non-fasting blood samples falls short of capturing the dynamics in lipid, ketone, carnitine and acylcarnitine concentrations. To enhance the utility of serum acylcarnitine analyses, we strongly recommend accounting for the specific time since the last meal at the time of blood sampling.

Fatty acid β-oxidation in brain mitochondria: Insights from high-resolution respirometry in mouse, rat and Drosophila brain, ischemia and aging models

Glucose is the main energy source of the brain, yet recent studies demonstrate that fatty acid oxidation (FAO) plays a relevant role in the pathogenesis of central nervous system disorders. We evaluated FAO in brain mitochondria under physiological conditions, in the aging brain, and after stroke. Using high-resolution respirometry we compared medium-chain (MC, octanoylcarnitine) and long-chain (LC, palmitoylcarnitine) acylcarnitines as substrates of β-oxidation in the brain. The protocols developed avoid FAO overestimation by malate-linked anaplerotic activity in brain mitochondria. The capacity of FA oxidative phosphorylation (F-OXPHOS) with palmitoylcarnitine was up to 4 times higher than respiration with octanoylcarnitine. The optimal concentration of palmitoylcarnitine was 10 μM which corresponds to the total concentration of LC acylcarnitines in the brain. Maximal respiration with octanoylcarnitine was reached at 20 μM, however, this concentration exceeds MC acylcarnitine concentrations in the brain 15 times. F-OXPHOS capacity was highest in mouse cerebellum, intermediate in cortex, prefrontal cortex, and hypothalamus, and hardly detectable in hippocampus. F-OXPHOS capacity was 2-fold lower and concentrations of LC acylcarnitines were 2-fold higher in brain of aged rats. A similar trend was observed in the rat model of endothelin-1-induced stroke, but reduction of OXPHOS capacity was not limited to FAO. In conclusion, although FAO is not a dominant pathway in brain bioenergetics, it deserves specific attention in studies of brain metabolism.

Pharmacometabolomics in Drug Disposition, Toxicity, and Precision Medicine

The precision medicine initiative has driven a substantial change in the way scientists and health care practitioners think about diagnosing and treating disease. While it has long been recognized that drug response is determined by the intersection of genetic, environmental, and disease factors, improvements in technology have afforded precision medicine guided dosing of drugs to improve efficacy and reduce toxicity. Pharmacometabolomics aims to evaluate small molecule metabolites in plasma and/or urine to help evaluate mechanisms that predict and/or reflect drug efficacy and toxicity. In this mini review, we provide an overview of pharmacometabolomic approaches and methodologies. Relevant examples where metabolomic techniques have been used to better understand drug efficacy and toxicity in major depressive disorder and cancer chemotherapy are discussed. In addition, the utility of metabolomics in drug development and understanding drug metabolism, transport, and pharmacokinetics is reviewed. Pharmacometabolomic approaches can help describe factors mediating drug disposition, efficacy, and toxicity. While important advancements in this area have been made, there remain several challenges that must be overcome before this approach can be fully implemented into clinical drug therapy. SIGNIFICANCE STATEMENT: Pharmacometabolomics has emerged as an approach to identify metabolites that allow for implementation of precision medicine approaches to pharmacotherapy. This review article provides an overview of pharmacometabolomics including highlights of important examples.

Rats exposed to Alternaria toxins in vivo exhibit altered liver activity highlighted by disruptions in riboflavin and acylcarnitine metabolism

Natural toxins produced by Alternaria fungi include the mycotoxins alternariol, tenuazonic acid and altertoxins I and II. Several of these toxins have shown high toxicity even at low levels including genotoxic, mutagenic, and estrogenic effects. However, the metabolic effects of toxin exposure from Alternaria are understudied, especially in the liver as a key target. To gain insight into the impact of Alternaria toxin exposure on the liver metabolome, rats (n = 21) were exposed to either (1) a complex culture extract with defined toxin profiles from Alternaria alternata (50 mg/kg body weight), (2) the isolated, highly genotoxic altertoxin-II (ATX-II) (0.7 mg/kg of body weight) or (3) a solvent control. The complex mixture contained a spectrum of Alternaria toxins including a controlled dose of ATX-II, matching the concentration of the isolated ATX-II. Liver samples were collected after 24 h and analyzed via liquid chromatography-high-resolution mass spectrometry (LC-HRMS). Authentic reference standards (> 100) were used to identify endogenous metabolites and exogenous compounds from the administered exposures in tandem with SWATH-acquired MS/MS data which was used for non-targeted analysis/screening. Screening for metabolites produced by Alternaria revealed several compounds solely isolated in the liver of rats exposed to the complex culture, confirming results from a previously performed targeted biomonitoring study. This included the altersetin and altercrasin A that were tentatively identified. An untargeted metabolomics analysis found upregulation of acylcarnitines in rats receiving the complex Alternaria extract as well as downregulation of riboflavin in rats exposed to both ATX-II and the complex mixture. Taken together, this work provides a mechanistic view of Alternari toxin exposure and new suspect screening insights into hardly characterized Alternaria toxins.

Transcriptomic and metabolomic changes might predict frailty in SAMP8 mice

Frailty is a geriatric, multi-dimensional syndrome that reflects multisystem physiological change and is a transversal measure of reduced resilience to negative events. It is characterized by weakness, frequent falls, cognitive decline, increased hospitalization and dead and represents a risk factor for the development of Alzheimer's disease (AD). The fact that frailty is recognized as a reversible condition encourages the identification of earlier biomarkers to timely predict and prevent its occurrence. SAMP8 (Senescence-Accelerated Mouse Prone-8) mice represent the most appropriate preclinical model to this aim and were used in this study to carry transcriptional and metabolic analyses in the brain and plasma, respectively, upon a characterization at cognitive, motor, structural, and neuropathological level at 2.5, 6, and 9 months of age. At 2.5 months, SAMP8 mice started displaying memory deficits, muscle weakness, and motor impairment. Functional alterations were associated with a neurodevelopmental deficiency associated with reduced neuronal density and glial cell loss. Through transcriptomics, we identified specific genetic signatures well distinguishing SAMP8 mice at 6 months, whereas plasma metabolomics allowed to segregate SAMP8 mice from SAMR1 already at 2.5 months of age by detecting constitutively lower levels of acylcarnitines and lipids in SAMP8 at all ages investigated correlating with functional deficits and neuropathological signs. Our findings suggest that specific genetic alterations at central level, as well as metabolomic changes in plasma, might allow to early assess a frail condition leading to dementia development, which paves the foundation for future investigation in a clinical setting.

Longitudinal characterization of the muscle metabolome in dairy cows during the transition from lactation cessation to lactation resumption

Skeletal muscle is vital in maintaining metabolic homeostasis and adapting to the physiological needs of pregnancy and lactation. Despite advancements in understanding metabolic changes in dairy cows around calving and early lactation, there are still gaps in our knowledge, especially concerning muscle metabolism and the changes associated with drying off. This study aimed to characterize the skeletal muscle metabolome in the context of the dietary and metabolic changes occurring during the transition from the cessation of lactation to the resumption of lactation in dairy cows. Twelve Holstein dairy cows housed in tie stalls were dried off 6 weeks (wk) before the expected calving date. Cows were individually fed ad libitum total mixed rations composed of grass silage, corn silage, and concentrate during lactation and of corn silage, barley straw, and concentrate during the dry period. The metabolome was characterized in skeletal muscle samples (M. longissimus dorsi) collected on wk -7 (9 d before dry-off), -5 (6 d after dry-off), and wk -1, and 1 relative to calving. The targeted metabolomics approach was conducted using the MxP Quant 500 kit (Biocrates Life Sciences AG) with liquid chromatography, flow injection, and electrospray ionization triple quadrupole mass spectrometry. Statistical analysis on the muscle metabolite data was performed using MetaboAnalyst 5.0, which allowed us to conduct various multivariate analyses such as principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), informative heat map generation, and hierarchical clustering. The statistical analysis revealed a clear separation between pregnancy (wk -7, -5, and -1) and post-calving (wk 1). Starting 5 wk before calving and continuing through the first wk thereafter, the concentration of 3-methylhistidine (3-MH) in the muscle increased. This coincided with an increase in the concentrations of 11 AA (Phe, His, Tyr, Trp, Arg, Asn, Leu, Ile, Gly, Ser, and Thr) in the first wk after calving, whereas Gln decreased. l-arginine pathway metabolites (homoarginine, ornithine, citrulline, and asymmetric dimethylarginine), betaine, and sarcosine followed a similar pattern, increasing from wk -7 to -5, but decreasing from wk -1 to 1. The transition from pregnancy to lactation was associated with an increase in concentrations of the long-chain acylcarnitine species C16, C16:1, C18, and C18:1 in the muscle, whereas the concentrations of phosphatidylcholine and sphingomyelin in the muscle remained stable. The significant changes observed in the metabolome mainly concerned the AA and AA-related metabolites, indicating muscle protein breakdown in the first wk after calving. The metabolites produced by the L-Arg pathway might contribute to regulating skeletal muscle mass and function in periparturient dairy cows. The elevated concentrations of long-chain acylcarnitine species in the muscle in the first wk after calving suggest incomplete fatty acid oxidation, likely due to insufficient metabolic adaptation in response to the fatty acid load around the time of calving.

Role of Mitochondrial Dysfunctions in Neurodegenerative Disorders: Advances in Mitochondrial Biology

Mitochondria, essential organelles responsible for cellular energy production, emerge as a key factor in the pathogenesis of neurodegenerative disorders. This review explores advancements in mitochondrial biology studies that highlight the pivotal connection between mitochondrial dysfunctions and neurological conditions such as Alzheimer's, Parkinson's, Huntington's, ischemic stroke, and vascular dementia. Mitochondrial DNA mutations, impaired dynamics, and disruptions in the ETC contribute to compromised energy production and heightened oxidative stress. These factors, in turn, lead to neuronal damage and cell death. Recent research has unveiled potential therapeutic strategies targeting mitochondrial dysfunction, including mitochondria targeted therapies and antioxidants. Furthermore, the identification of reliable biomarkers for assessing mitochondrial dysfunction opens new avenues for early diagnosis and monitoring of disease progression. By delving into these advancements, this review underscores the significance of understanding mitochondrial biology in unraveling the mechanisms underlying neurodegenerative disorders. It lays the groundwork for developing targeted treatments to combat these devastating neurological conditions.

Animal Food Products to Support Human Nutrition and to Boost Human Health: The Potential of Feedstuffs Resources and Their Metabolites as Health-Promoters

Recent attention has been given to animal feeding and its impact on human nutrition. Animal feeding is essential for meeting human dietary needs, making it a subject of significant interest and investigation. This review seeks to outline the current understanding of this disciplinary area, with a focus on key research areas and their potential implications. The initial part of the paper discusses the importance of animal feed resources and recognizes their crucial role in guaranteeing sufficient nutrition for both humans and animals. Furthermore, we analyzed the categorization of animal feeds based on the guidelines established by the National Research Council. This approach offers a valuable structure for comprehending and classifying diverse types of animal feed. Through an examination of this classification, we gain an understanding of the composition and nutritional content of various feedstuffs. We discuss the major categories of metabolites found in animal feed and their impact on animal nutrition, as well as their potential health advantages for humans. Flavonoids, polyphenols, tannins, terpenoids, vitamins, antioxidants, alkaloids, and essential oils are the primary focus of the examination. Moreover, we analyzed their possible transference into animal products, and later we observed their occurrence in foods from animal sources. Finally, we discuss their potential to promote human health. This review offers an understanding of the connections among the major metabolites found in feedstuffs, their occurrence in animal products, and their possible impact on the health of both animals and humans.

Metabolomic biomarkers of multiple myeloma: A systematic review

Multiple myeloma (MM) is an incurable malignancy of clonal plasma cells. Various diagnostic methods are used in parallel to accurately determine stage and severity of the disease. Identifying a biomarker or a panel of biomarkers could enhance the quality of medical care that patients receive by adopting a more personalized approach. Metabolomics utilizes high-throughput analytical platforms to examine the levels and quantities of biochemical compounds in biosamples. The aim of this review was to conduct a systematic literature search for potential metabolic biomarkers that may aid in the diagnosis and prognosis of MM. The review was conducted in accordance with PRISMA recommendations and was registered in PROSPERO. The systematic search was performed in PubMed, CINAHL, SciFinder, Scopus, The Cochrane Library and Google Scholar. Studies were limited to those involving people with clinically diagnosed MM and healthy controls as comparators. Articles had to be published in English and had no restrictions on publication date or sample type. The quality of articles was assessed according to QUADOMICS criteria. A total of 709 articles were collected during the literature search. Of these, 436 were excluded based on their abstract, with 26 more removed after a thorough review of the full text. Finally, 16 articles were deemed relevant and were subjected to further analysis of their data. A number of promising candidate biomarkers was discovered. Follow-up studies with large sample sizes are needed to determine their suitability for clinical applications.

NMR-based metabolomics analysis reveals the effect of environmental contamination exposure on fishermen living around the Mundaú Lagoon in Maceió (Alagoas, Brazil)

The Mundaú lagoon in Maceió (Alagoas, Brazil) is a crucial resource for the local population, particularly fishing communities. Recent studies have revealed potential toxic metal contamination in the lagoon, particularly with mercury (Hg) levels exceeding the maximum regulated values. This inorganic contaminant may be impacting the health of fishermen and the local population. In this context, metabolomics, a study of small-molecule metabolites, can offer insights into the physiological impact of environmental contamination on humans. Thus, volunteers from the control and exposed groups were selected, considering the main exposure criteria primarily defined by their proximity and interaction with the lagoon. Blood and urine samples were collected from the volunteers and subjected to analysis using NMR spectroscopy. The data underwent Principal Component Analysis (PCA) and Orthogonal Partial Least-Squares Discriminant Analysis (OPLS-DA) based on metabolic patterns to establish group discrimination or identification. Metabolic pathways were assessed through enrichment analysis. The study revealed several metabolic disturbances in the exposed group's urine and plasma samples compared to control group. Noteworthy findings included arginine and proline metabolism disruptions, indicative of ammonia recycling and urea cycle impairment. These changes suggest compromised ammonia detoxification in the exposed group. Disturbances in the tricarboxylic acid (TCA) cycle and the transfer of acetyl groups into mitochondria suggested systemic metabolic stress in energy metabolism. Furthermore, elevated carnitine and ketone levels may indicate compensatory responses to low TCA cycle activity. Alterations in glutamate and glutathione metabolism and imbalances in glutathione levels indicate oxidative stress and impaired detoxification. This study highlights significant metabolic changes in fishermen exposed to contaminated environments, which can affect various metabolic pathways, including energy metabolism and antioxidant processes, potentially making individuals more vulnerable to the adverse effects of environmental contaminants. Finally, this work highlights insights into the relationship between environmental contamination and metabolic pathways, particularly in regions with limited studies.

Acute inhibition of iron-sulfur cluster biosynthesis disrupts metabolic flexibility in mice

Iron-sulfur clusters (ISCs) are cell-essential cofactors present in ∼60 proteins including subunits of OXPHOS complexes I-III, DNA polymerases, and iron-sensing proteins. Dysfunctions in ISC biosynthesis are associated with anemias, neurodegenerative disorders, and metabolic diseases. To assess consequences of acute ISC inhibition in a whole body setting, we developed a mouse model in which key ISC biosynthetic enzyme NFS1 can be acutely and reversibly suppressed. Contrary to in vitro ISC inhibition and pharmacological OXPHOS suppression, global NFS1 inhibition rapidly enhances lipid utilization and decreases adiposity without affecting caloric intake and physical activity. ISC proteins decrease, including key proteins involved in OXPHOS (SDHB), lipoic acid synthesis (LIAS), and insulin mRNA processing (CDKAL1), causing acute metabolic inflexibility. Age-related metabolic changes decelerate loss of adiposity substantially prolonged survival of mice with NFS1 inhibition. Thus, the observation that ISC metabolism impacts organismal fuel choice will aid in understanding the mechanisms underlying ISC diseases with increased risk for diabetes.

Graphical abstract

Highlights

Acute ISC inhibition leads to rapid loss of adiposity in miceMulti-metabolic pathway disruption upon ISC deficiency blocks energy storageNfs1 inhibition induces glucose dyshomeostasis due to ISC deficiency in β-cellsEnergy distress caused by inhibition of ISC synthesis is attenuated in aged mice.

Biomarker Landscape in RASopathies

RASopathies are a group of related genetic disorders caused by mutations in genes within the RAS/MAPK signaling pathway. This pathway is crucial for cell division, growth, and differentiation, and its disruption can lead to a variety of developmental and health issues. RASopathies present diverse clinical features and pose significant diagnostic and therapeutic challenges. Studying the landscape of biomarkers in RASopathies has the potential to improve both clinical practices and the understanding of these disorders. This review provides an overview of recent discoveries in RASopathy molecular profiling, which extend beyond traditional gene mutation analysis. mRNAs, non-coding RNAs, protein expression patterns, and post-translational modifications characteristic of RASopathy patients within pivotal signaling pathways such as the RAS/MAPK, PI3K/AKT/mTOR, and Rho/ROCK/LIMK2/cofilin pathways are summarized. Additionally, the field of metabolomics holds potential for uncovering metabolic signatures associated with specific RASopathies, which are crucial for developing precision medicine. Beyond molecular markers, we also examine the role of histological characteristics and non-invasive physiological assessments in identifying potential biomarkers, as they provide evidence of the disease's effects on various systems. Here, we synthesize key findings and illuminate promising avenues for future research in RASopathy biomarker discovery, underscoring rigorous validation and clinical translation.

Alterations of plasma metabolomes and their correlations with immunogenicity in maintenance hemodialysis patients receiving different COVID-19 vaccine regimens

Maintenance hemodialysis (MHD) patients exhibit compromised immune responses, leading to lower immunogenicity to the COVID-19 vaccine than the general population. The metabolomic factors influencing COVID-19 vaccine response in MHD patients remain elusive. A cross-sectional study was conducted with 30 MHD patients, divided into three vaccine regimen groups (N= 10 per group): homologous CoronaVac® (SV-SV), homologous ChAdOx1 nCoV-19 (AZ-AZ), and heterologous prime-boost (SV-AZ). Plasma samples were collected at baseline and at 28 days after the final dose to analyze 92 metabolomic levels using targeted metabolomics. The study included 30 MHD patients (mean age 56.67 ± 10.79 years) with similar neutralizing antibody (nAb) levels across vaccine regimens. The most significant differences in metabolomics were found between AZ-AZ and SV-SV, followed by SV-AZ versus SV-SV, and AZ-AZ versus SV-AZ. Overall, the metabolomic changes involved amino acids like glutamate and phenylalanine, and phospholipids. Prevaccination metabolomic profiles, including PG (38:1), lysoPE (20:2), lysoPC (18:2), lysoPI (18:1), and PC (34:2), exhibited negative correlations with postvaccination nAb levels. Different COVID-19 vaccine regimens had unique interactions with the immune response in MHD patients. Amino acid and phospholipid metabolisms play crucial roles in nAb formation, with the phospholipid metabolism being a potentially predictive marker of vaccine immunogenicity among MHD patients.

Systemic acylcarnitine levels are affected in response to multiple injuries and hemorrhagic shock: An analysis of lipidomic changes in a standardized porcine model

INTRODUCTION

Along with recent advances in analytical technologies, tricarboxylic acid-cycle intermediates are increasingly identified as promising makers for cellular ischemia and mitochondrial dysfunction during hemorrhagic shock. For traumatized patients, the knowledge of the role of lipid oxidation substrates is sparse. In this study, we aimed to analyze the dynamics of systemic acylcarnitine (AcCa) release in a standardized polytrauma model with hemorrhagic shock.

METHODS

Fifty-two male pigs (50 ± 5 kg) were randomized into two groups: group isolated fracture was subject to a standardized femur shaft fracture, and group polytrauma was subject to a femur fracture, followed by blunt chest trauma, liver laceration, and a pressure-controlled hemorrhagic shock for 60 minutes. Resuscitation was performed with crystalloids. Fractures were stabilized by intramedullary nailing. Venous samples were collected at six time points (baseline, trauma, resuscitation, 2 hours, 4 hours, and 6 hours). Lipidomic analysis was performed via liquid chromatography coupled mass spectrometry. Measurements were collated with clinical markers and near-infrared spectrometry measurements of tissue perfusion. Longitudinal analyses were performed with linear mixed models, and Spearman's correlations were calculated. A p value of 0.05 was defined as threshold for statistical significance.

RESULTS

From a total of 303 distinct lipids, we identified two species of long-chain AcCas. Both showed a highly significant ( p < 0.001) twofold increase after hemorrhagic shock in group polytrauma that promptly normalized after resuscitation. This increase was associated with a significant decrease of the base excess ( p = 0.005), but recovery after resuscitation was faster. For both AcCas, there were significant correlations with decreased muscle tissue oxygen delivery ( p = 0.008, p = 0.003) and significant time-lagged correlations with the increase of creatine kinase ( p < 0.001, p < 0.001).

CONCLUSION

Our results point to plasma AcCas as a possible indicator for mitochondrial dysfunction and cellular ischemia in hemorrhagic shock. The more rapid normalization after resuscitation in comparison with acid base changes may warrant further investigation.

Advancements, Challenges, and clinical implications of integration of metabolomics technologies in diabetic nephropathy

BACKGROUND

Diabetic nephropathy (DN), a severe complication of diabetes, involves a range of renal abnormalities driven by metabolic derangements. Metabolomics, revealing dynamic metabolic shifts in diseases like DN and offering insights into personalized treatment strategies, emerges as a promising tool for improved diagnostics and therapies.

METHODS

We conducted an extensive literature review to examine how metabolomics contributes to the study of DN and the challenges associated with its implementation in clinical practice. We identified and assessed relevant studies that utilized metabolomics methods, including nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS) to assess their efficacy in diagnosing DN.

RESULTS

Metabolomics unveils key pathways in DN progression, highlighting glucose metabolism, dyslipidemia, and mitochondrial dysfunction. Biomarkers like glycated albumin and free fatty acids offer insights into DN nuances, guiding potential treatments. Metabolomics detects small-molecule metabolites, revealing disease-specific patterns for personalized care.

CONCLUSION

Metabolomics offers valuable insights into the molecular mechanisms underlying DN progression and holds promise for personalized medicine approaches. Further research in this field is warranted to elucidate additional metabolic pathways and identify novel biomarkers for early detection and targeted therapeutic interventions in DN.

Comparative Determination of Mitochondrial Biomarkers and Their Relationship With Insulin Resistance in Type 2 Diabetic Patients: An Observational Cross-Sectional Study

INTRODUCTION

Data suggest malfunctioning mitochondria reduce oxidation and adenosine triphosphate (ATP) production, disrupting insulin signalling. Cytochrome c (CC), acylcarnitine (AC) and citrate synthase (CS) are essential components of the mitochondria machinery and can be used as reliable biomarkers of mitochondrial dysfunction. This study aimed to determine whether mitochondrial biomarkers (AC, CS and CC) are altered in individuals with type 2 diabetes mellitus (T2DM) and to examine the association between these biomarkers and insulin resistance.

METHODOLOGY

A cross-sectional observational study that recruited 170 participants (88 with T2DM and 82 without DM) was conducted. Blood samples were collected from the recruits and analysed for levels of fasting glucose (FBG), AC, CS, CC, insulin, total cholesterol, triglycerides (TG), glycated haemoglobin (HbA1c) and magnesium. Blood pressure (BP) and anthropometric characteristics of participants were also taken. Appropriate formulas were used to determine %body fat, body mass index (BMI), waist-to-hip ratio (WHR), the homeostatic model assessment for insulin resistance (HOMA-IR) and insulin sensitivity (HOMA-β).

RESULTS

Patients with T2DM had higher levels of CC, %body fat, FBG, TG, HbA1c, BMI and HOMA-IR than controls (p < 0.05, respectively). Results showed a significant relationship between circulating CC levels versus HOMA-β (r = -0.40, p = 0.001), CS (r = -0.70, p = 0.001) and AC (r = -0.72, p = 0.001) levels in patients with T2DM. The adjusted odds increased in the T2DM patients for VLDL (OR = 6.66, p = 0.002), HbA1c (OR = 6.50, p = 0.001), FPG (OR = 3.17, p = 0.001), TG (OR = 2.36, p = 0.010), being female (OR = 2.09, p = 0.020) and CC (OR = 1.14, p = 0.016).

CONCLUSION

Overall, alterations in mitochondrial biomarkers, measured by AC, CC and CS, were observed in people with T2DM and showed a direct relationship with insulin resistance. These findings are potentially significant in Africa, although additional confirmation from a larger cohort is necessary.

Integrative Analyses of Circulating Proteins and Metabolites Reveal Sex Differences in the Associations with Cardiac Function among DCM Patients

Dilated cardiomyopathy (DCM) is characterized by reduced left ventricular ejection fraction (LVEF) and left or biventricular dilatation. We evaluated sex-specific associations of circulating proteins and metabolites with structural and functional heart parameters in DCM. Plasma samples (297 men, 71 women) were analyzed for proteins using Olink assays (targeted analysis) or LC-MS/MS (untargeted analysis), and for metabolites using LC MS/MS (Biocrates AbsoluteIDQ p180 Kit). Associations of proteins (n = 571) or metabolites (n = 163) with LVEF, measured left ventricular end diastolic diameter (LVEDDmeasured), and the dilation percentage of LVEDD from the norm (LVEDDacc. to HENRY) were examined in combined and sex-specific regression models. To disclose protein-metabolite relations, correlation analyses were performed. Associations between proteins, metabolites and LVEF were restricted to men, while associations with LVEDD were absent in both sexes. Significant metabolites were validated in a second independent DCM cohort (93 men). Integrative analyses demonstrated close relations between altered proteins and metabolites involved in lipid metabolism, inflammation, and endothelial dysfunction with declining LVEF, with kynurenine as the most prominent finding. In DCM, the loss of cardiac function was reflected by circulating proteins and metabolites with sex-specific differences. Our integrative approach demonstrated that concurrently assessing specific proteins and metabolites might help us to gain insights into the alterations associated with DCM.

Towards Healthy Longevity: Comprehensive Insights from Molecular Targets and Biomarkers to Biological Clocks

Aging is a complex and time-dependent decline in physiological function that affects most organisms, leading to increased risk of age-related diseases. Investigating the molecular underpinnings of aging is crucial to identify geroprotectors, precisely quantify biological age, and propose healthy longevity approaches. This review explores pathways that are currently being investigated as intervention targets and aging biomarkers spanning molecular, cellular, and systemic dimensions. Interventions that target these hallmarks may ameliorate the aging process, with some progressing to clinical trials. Biomarkers of these hallmarks are used to estimate biological aging and risk of aging-associated disease. Utilizing aging biomarkers, biological aging clocks can be constructed that predict a state of abnormal aging, age-related diseases, and increased mortality. Biological age estimation can therefore provide the basis for a fine-grained risk stratification by predicting all-cause mortality well ahead of the onset of specific diseases, thus offering a window for intervention. Yet, despite technological advancements, challenges persist due to individual variability and the dynamic nature of these biomarkers. Addressing this requires longitudinal studies for robust biomarker identification. Overall, utilizing the hallmarks of aging to discover new drug targets and develop new biomarkers opens new frontiers in medicine. Prospects involve multi-omics integration, machine learning, and personalized approaches for targeted interventions, promising a healthier aging population.

Cross-species metabolomic profiling reveals phosphocholine-mediated liver protection from cold and ischemia/reperfusion

Cold and ischemia/reperfusion (IR)-associated injuries are seemingly inevitable during liver transplantation and hepatectomy. Because Syrian hamsters demonstrate intrinsic tolerance to transplantation-like stimuli, cross-species comparative metabolomic analyses were conducted with hamster, rat, and donor liver samples to seek hepatic cold and IR-adaptive mechanisms. Lower hepatic phosphocholine contents were found in recipients with early graft-dysfunction and with virus-caused cirrhosis or high model for end-stage liver disease scores (≥30). Choline/phosphocholine deficiency in cultured human THLE-2 hepatocytes and animal models weakened hepatocellular cold tolerance and recovery of glutathione and ATP production, which was rescued by phosphocholine supplements. Among the biological processes impacted by choline/phosphocholine deficiency, 3 lipid-related metabolic processes were downregulated, whereas phosphocholine elevated the expression of genes in methylation processes. Consistently, in THLE-2, phosphocholine enhanced the overall RNA m6A methylation, among which the transcript stability of fatty acid desaturase 6 (FADS6) was improved. FADS6 functioned as a key phosphocholine effector in the production of polyunsaturated fatty acids, which may facilitate the hepatocellular recovery of energy and redox homeostasis. Thus, our study reveals the choline-phosphocholine metabolism and its downstream FADS6 functions in hepatic adaptation to cold and IR, which may inspire new strategies to monitor donor liver quality and improve recipient recovery from the liver transplantation process.

Determination of amino acid metabolic diseases from dried blood spots with a rapid extraction method coupled with nanoelectrospray ionization mass spectrometry

In this work, a rapid extraction method of methanol/water (95:5 v/v) with 0.1% formic acid was developed for extraction of amino acids from dried blood spots (DBS) for inherited metabolic diseases (IMDs). The combination of this extraction procedure with nanoelectrospray ionization mass spectrometry (nESI-MS) was used for the rapid analysis of amino acids. This approach with eliminating the chromatographic separation required only 2 min for the extraction of amino acids from DBS, which simplified the configuration and improved the timeliness. Dependence of the sensitivity on the operating parameters was systematically investigated. The LOD of 91.2-262.5 nmol/L and LOQ of 304-875 nmol/L which were lower than the cut-off values were obtained for amino acids within DBS. The accuracy was determined to be 93.82%-103.07% and the precision was determined to be less than 8.30%. The effectiveness of this method was also compared with the gold standard method (e.g., LC-MS/MS). The desalination mechanism was explored with interference mainly originated from the blood. These findings indicated that the rapid extraction procedure coupled with nESI-MS is capable of screening indicators for IMDs in complex biological samples.

Metabolic predictors of COVID-19 mortality and severity: a survival analysis

Introduction

The global healthcare burden of COVID-19 pandemic has been unprecedented with a high mortality. Metabolomics, a powerful technique, has been increasingly utilized to study the host response to infections and to understand the progression of multi-system disorders such as COVID-19. Analysis of the host metabolites in response to SARS-CoV-2 infection can provide a snapshot of the endogenous metabolic landscape of the host and its role in shaping the interaction with SARS-CoV-2. Disease severity and consequently the clinical outcomes may be associated with a metabolic imbalance related to amino acids, lipids, and energy-generating pathways. Hence, the host metabolome can help predict potential clinical risks and outcomes.

Methods

In this prospective study, using a targeted metabolomics approach, we studied the metabolic signature in 154 COVID-19 patients (males=138, age range 48-69 yrs) and related it to disease severity and mortality. Blood plasma concentrations of metabolites were quantified through LC-MS using MxP Quant 500 kit, which has a coverage of 630 metabolites from 26 biochemical classes including distinct classes of lipids and small organic molecules. We then employed Kaplan-Meier survival analysis to investigate the correlation between various metabolic markers, disease severity and patient outcomes.

Results

A comparison of survival outcomes between individuals with high levels of various metabolites (amino acids, tryptophan, kynurenine, serotonin, creatine, SDMA, ADMA, 1-MH and carnitine palmitoyltransferase 1 and 2 enzymes) and those with low levels revealed statistically significant differences in survival outcomes. We further used four key metabolic markers (tryptophan, kynurenine, asymmetric dimethylarginine, and 1-Methylhistidine) to develop a COVID-19 mortality risk model through the application of multiple machine-learning methods.

Conclusions

Metabolomics analysis revealed distinct metabolic signatures among different severity groups, reflecting discernible alterations in amino acid levels and perturbations in tryptophan metabolism. Notably, critical patients exhibited higher levels of short chain acylcarnitines, concomitant with higher concentrations of SDMA, ADMA, and 1-MH in severe cases and non-survivors. Conversely, levels of 3-methylhistidine were lower in this context.

Drug-Induced Fatty Liver Disease (DIFLD): A Comprehensive Analysis of Clinical, Biochemical, and Histopathological Data for Mechanisms Identification and Consistency with Current Adverse Outcome Pathways

Drug induced fatty liver disease (DIFLD) is a form of drug-induced liver injury (DILI), which can also be included in the more general metabolic dysfunction-associated steatotic liver disease (MASLD), which specifically refers to the accumulation of fat in the liver unrelated to alcohol intake. A bi-directional relationship between DILI and MASLD is likely to exist: while certain drugs can cause MASLD by acting as pro-steatogenic factors, MASLD may make hepatocytes more vulnerable to drugs. Having a pre-existing MASLD significantly heightens the likelihood of experiencing DILI from certain medications. Thus, the prevalence of steatosis within DILI may be biased by pre-existing MASLD, and it can be concluded that the genuine true incidence of DIFLD in the general population remains unknown. In certain individuals, drug-induced steatosis is often accompanied by concomitant injury mechanisms such as oxidative stress, cell death, and inflammation, which leads to the development of drug-induced steatohepatitis (DISH). DISH is much more severe from the clinical point of view, has worse prognosis and outcome, and resembles MASH (metabolic-associated steatohepatitis), as it is associated with inflammation and sometimes with fibrosis. A literature review of clinical case reports allowed us to examine and evaluate the clinical features of DIFLD and their association with specific drugs, enabling us to propose a classification of DIFLD drugs based on clinical outcomes and pathological severity: Group 1, drugs with low intrinsic toxicity (e.g., ibuprofen, naproxen, acetaminophen, irinotecan, methotrexate, and tamoxifen), but expected to promote/aggravate steatosis in patients with pre-existing MASLD; Group 2, drugs associated with steatosis and only occasionally with steatohepatitis (e.g., amiodarone, valproic acid, and tetracycline); and Group 3, drugs with a great tendency to transit to steatohepatitis and further to fibrosis. Different mechanisms may be in play when identifying drug mode of action: (1) inhibition of mitochondrial fatty acid β-oxidation; (2) inhibition of fatty acid transport across mitochondrial membranes; (3) increased de novo lipid synthesis; (4) reduction in lipid export by the inhibition of microsomal triglyceride transfer protein; (5) induction of mitochondrial permeability transition pore opening; (6) dissipation of the mitochondrial transmembrane potential; (7) impairment of the mitochondrial respiratory chain/oxidative phosphorylation; (8) mitochondrial DNA damage, degradation and depletion; and (9) nuclear receptors (NRs)/transcriptomic alterations. Currently, the majority of, if not all, adverse outcome pathways (AOPs) for steatosis in AOP-Wiki highlight the interaction with NRs or transcription factors as the key molecular initiating event (MIE). This perspective suggests that chemical-induced steatosis typically results from the interplay between a chemical and a NR or transcription factors, implying that this interaction represents the primary and pivotal MIE. However, upon conducting this exhaustive literature review, it became evident that the current AOPs tend to overly emphasize this interaction as the sole MIE. Some studies indeed support the involvement of NRs in steatosis, but others demonstrate that such NR interactions alone do not necessarily lead to steatosis. This view, ignoring other mitochondrial-related injury mechanisms, falls short in encapsulating the intricate biological mechanisms involved in chemically induced liver steatosis, necessitating their consideration as part of the AOP's map road as well.

The impact of normothermic and hypothermic preservation methods on kidney lipidome-comparative study using chemical biopsy with microextraction probes

Introduction

Normothermic ex vivo kidney perfusion (NEVKP) is designed to replicate physiological conditions to improve graft outcomes. A comparison of the impact of hypothermic and normothermic preservation techniques on graft quality was performed by lipidomic profiling using solid-phase microextraction (SPME) chemical biopsy as a minimally invasive sampling approach.

Methods

Direct kidney sampling was conducted using SPME probes coated with a mixed-mode extraction phase in a porcine autotransplantation model of the renal donor after cardiac death, comparing three preservation methods: static cold storage (SCS), NEVKP, and hypothermic machine perfusion (HMP). The lipidomic analysis was done using ultra-high-performance liquid chromatography coupled with a Q-Exactive Focus Orbitrap mass spectrometer.

Results

Chemometric analysis showed that the NEVLP group was separated from SCS and HMP groups. Further in-depth analyses indicated significantly (p < 0.05, VIP > 1) higher levels of acylcarnitines, phosphocholines, ether-linked and longer-chain phosphoethanolamines, triacylglycerols and most lysophosphocholines and lysophosphoethanolamines in the hypothermic preservation group. The results showed that the preservation temperature has a more significant impact on the lipidomic profile of the kidney than the preservation method's mechanical characteristics.

Conclusion

Higher levels of lipids detected in the hypothermic preservation group may be related to ischemia-reperfusion injury, mitochondrial dysfunction, pro-inflammatory effect, and oxidative stress. Obtained results suggest the NEVKP method's beneficial effect on graft function and confirm that SPME chemical biopsy enables low-invasive and repeated sampling of the same tissue, allowing tracking alterations in the graft throughout the entire transplantation procedure.

Serum and urine lipidomic profiles identify biomarkers diagnostic for seropositive and seronegative rheumatoid arthritis

Objective

Seronegative rheumatoid arthritis (RA) is defined as RA without circulating autoantibodies such as rheumatoid factor and anti-citrullinated protein antibodies; thus, early diagnosis of seronegative RA can be challenging. Here, we aimed to identify diagnostic biomarkers for seronegative RA by performing lipidomic analyses of sera and urine samples from patients with RA.

Methods

We performed untargeted lipidomic analysis of sera and urine samples from 111 RA patients, 45 osteoarthritis (OA) patients, and 25 healthy controls (HC). These samples were divided into a discovery cohort (n = 97) and a validation cohort (n = 84). Serum samples from 20 patients with systemic lupus erythematosus (SLE) were also used for validation.

Results

The serum lipidome profile of RA was distinguishable from that of OA and HC. We identified a panel of ten serum lipids and three urine lipids in the discovery cohort that showed the most significant differences. These were deemed potential lipid biomarker candidates for RA. The serum lipid panel was tested using a validation cohort; the results revealed an accuracy of 79%, a sensitivity of 71%, and a specificity of 86%. Both seropositive and seronegative RA patients were differentiated from patients with OA, SLE, and HC. Three urinary lipids showing differential expression between RA from HC were identified with an accuracy of 84%, but they failed to differentiate RA from OA. There were five lipid pathways that differed between seronegative and seropositive RA.

Conclusion

Here, we identified a panel of ten serum lipids as potential biomarkers that can differentiate RA from OA and SLE, regardless of seropositivity. In addition, three urinary lipids had diagnostic utility for differentiating RA from HC.

Novel PLGA-based nanoformulation decreases doxorubicin-induced cardiotoxicity

Nanotechnology has the potential to provide formulations of antitumor agents with increased selectivity towards cancer tissue thereby decreasing systemic toxicity. This in vivo study evaluated the potential of novel nanoformulation based on poly(lactic-co-glycolic acid) (PLGA) to reduce the cardiotoxic potential of doxorubicin (DOX). In vivo toxicity of PLGADOX was compared with clinically approved non-PEGylated, liposomal nanoformulation of DOX (LipoDOX) and conventional DOX form (ConvDOX). The study was performed using Wistar Han rats of both sexes that were treated intravenously for 28 days with 5 doses of tested substances at intervals of 5 days. Histopathological analyses of heart tissues showed the presence of myofiber necrosis, degeneration processes, myocytolysis, and hemorrhage after treatment with ConvDOX, whereas only myofiber degeneration and hemorrhage were present after the treatment with nanoformulations. All DOX formulations caused an increase in the troponin T with the greatest increase caused by convDOX. qPCR analyses revealed an increase in the expression of inflammatory markers IL-6 and IL-8 after ConvDOX and an increase in IL-8 expression after lipoDOX treatments. The mass spectra imaging (MSI) of heart tissue indicates numerous metabolic and lipidomic changes caused by ConvDOX, while less severe cardiac damages were found after treatment with nanoformulations. In the case of LipoDOX, autophagy and apoptosis were still detectable, whereas PLGADOX induced only detectable mitochondrial toxicity. Cardiotoxic effects were frequently sex-related with the greater risk of cardiotoxicity observed mostly in male rats.

Pathophysiological roles of the serum acylcarnitine level and acylcarnitine/free carnitine ratio in patients with cardiovascular diseases

Introduction

L-carnitine exerts protective effects, such as maintaining mitochondrial functions and decreasing reactive oxygen species, while acylcarnitine (AC) is linked to the development of heart failure and atherosclerosis.

Hypothesis

Serum carnitines play important pathophysiological roles in cardiovascular diseases.

Methods

Pre-operative biochemical data were obtained from 117 patients (71 men, average age 69.9 years) who underwent surgery for cardiovascular diseases. Measurements included pre-operative biochemical data including estimated glomerular filtration rate (eGFR), physical functions, skeletal muscle mass index (SMI) measured by bioelectrical impedance analysis, anterior thigh muscle thickness (MTh) measured by ultrasound, and routine echocardiography. Carnitine components were measured with the enzyme cycling method. Muscle wasting was diagnosed based on the Asian Working Group for Sarcopenia criteria.

Results

Plasma brain natriuretic peptide (BNP) level was correlated with serum free carnitine (FC) and AC level, and the acylcarnitine/free carnitine ratio (AC/FC). AC/FC was elevated with stage of chronic kidney disease. In multivariate analysis, log (eGFR) and log (BNP) were extracted as independent factors to define log (serum AC) (eGFR: β = 0.258, p = 0.008; BNP: β = 0.273, p = 0.011), even if corrected for age, sex and body mass index. AC/FC was negatively correlated with hand-grip strength (r = -0.387, p = 0.006), SMI (r = -0.314, p = 0.012), and anterior thigh MTh (r = -0.340, p = 0.014) in men.

Conclusions

A significant association between serum AC level and AC/FC, and chronic kidney disease and heart failure exists in patients with cardiovascular diseases who have undergone cardiovascular surgery. Skeletal muscle loss and muscle wasting are also linked to the elevation of serum AC level and AC/FC.

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

BACKGROUND

Due to their complexity and to the presence of common clinical features, differentiation between asthma and chronic obstructive pulmonary disease (COPD) can be a challenging task, complicated in such cases also by asthma-COPD overlap syndrome. The distinct immune/inflammatory and structural substrates of COPD and asthma are responsible for significant differences in the responses to standard pharmacologic treatments. Therefore, an accurate diagnosis is of central relevance to assure the appropriate therapeutic intervention in order to achieve safe and effective patient care. Induced sputum (IS) accurately mirrors inflammation in the airways, providing a more direct picture of lung cell metabolism in comparison to those specimen that reflect analytes in the systemic circulation.

METHODS

An integrated untargeted metabolomics and lipidomics analysis was performed in IS of asthmatic (n = 15) and COPD (n = 22) patients based on Ultra-High-Pressure Liquid Chromatography-Mass Spectrometry (UHPLC-MS) and UHPLC-tandem MS (UHPLC-MS/MS). Partial Least Squares-Discriminant Analysis (PLS-DA) was applied to resulting dataset. The analysis of main enriched metabolic pathways and the association of the preliminary metabolites/lipids pattern identified to clinical parameters of asthma/COPD differentiation were explored. Multivariate ROC analysis was performed in order to determine the discriminatory power and the reliability of the putative biomarkers for diagnosis between COPD and asthma.

RESULTS

PLS-DA indicated a clear separation between COPD and asthmatic patients. Among the 15 selected candidate biomarkers based on Variable Importance in Projection scores, putrescine showed the highest score. A differential IS bio-signature of 22 metabolites and lipids was found, which showed statistically significant variations between asthma and COPD. Of these 22 compounds, 18 were decreased and 4 increased in COPD compared to asthmatic patients. The IS levels of Phosphatidylethanolamine (PE) (34:1), Phosphatidylglycerol (PG) (18:1;18:2) and spermine were significantly higher in asthmatic subjects compared to COPD.

CONCLUSIONS

This is the first pilot study to analyse the IS metabolomics/lipidomics signatures relevant in discriminating asthma vs COPD. The role of polyamines, of 6-Hydroxykynurenic acid and of D-rhamnose as well as of other important players related to the alteration of glycerophospholipid, aminoacid/biotin and energy metabolism provided the construction of a diagnostic model that, if validated on a larger prospective cohort, might be used to rapidly and accurately discriminate asthma from COPD.

Anti-Melanoma Effects of Miconazole: Investigating the Mitochondria Involvement

Miconazole is an antimycotic drug showing anti-cancer effects in several cancers. However, little is known on its effects in melanoma. A375 and SK-MEL-28 human melanoma cell lines were exposed to miconazole and clotrimazole (up to 100 mM). Proliferation, viability with MTT assay and vascular mimicry were assayed at 24 h treatment. Molecular effects were measured at 6 h, namely, ATP-, ROS-release and mitochondria-related cytofluorescence. A metabolomic profile was also investigated at 6 h treatment. Carnitine was one of the most affected metabolites; therefore, the expression of 29 genes involved in carnitine metabolism was investigated in the public platform GEPIA2 on 461 melanoma patients and 558 controls. After 24 h treatments, miconazole and clotrimazole strongly and significantly inhibited proliferation in the presence of 10% serum on either melanoma cell lines; they also strongly reduced viability and vascular mimicry. After 6 h treatment, ATP reduction and ROS increase were observed, as well as a significant reduction in mitochondria-related fluorescence. Further, in A375, miconazole strongly and significantly altered expression of several metabolites including carnitines, phosphatidyl-cholines, all amino acids and several other small molecules, mostly metabolized in mitochondria. The expression of 12 genes involved in carnitine metabolism was found significantly modified in melanoma patients, 6 showing a significant impact on patients' survival. Finally, miconazole antiproliferation activity on A375 was found completely abrogated in the presence of carnitine, supporting a specific role of carnitine in melanoma protection toward miconazole effect, and was significantly reversed in the presence of caspases inhibitors such as ZVAD-FMK and Ac-DEVD-CHO, and a clear pro-apoptotic effect was observed in miconazole-treated cells, by FACS analysis of Annexin V-FITC stained cells. Miconazole strongly affects proliferation and other biological features in two human melanoma cell lines, as well as mitochondria-related functions such as ATP- and ROS-release, and the expression of several metabolites is largely dependent on mitochondria function. Miconazole, likely acting via carnitine and mitochondria-dependent apoptosis, is therefore suggested as a candidate for further investigations in melanoma treatments.

Effect of age on metabolomic changes in a model of paclitaxel-induced peripheral neurotoxicity

BACKGROUND AND AIMS

Chemotherapy-induced peripheral neurotoxicity (CIPN) is one of the most common dose-limiting side effects of paclitaxel (PTX) treatment. Many age-related changes have been hypothesized to underlie susceptibility to damage or impaired regeneration/repair after nerve injury. The results of these studies, however, are inconclusive and other potential biomarkers of nerve impairment need to be investigated.

METHODS

Twenty-four young (2 months) and 24 adult (9 months) Wistar male rats were randomized to either PTX treatment (10 mg/kg i.v. once/week for 4 weeks) or vehicle administration. Neurophysiological and behavioral tests were performed at baseline, after 4 weeks of treatment and 2-week follow-up. Skin biopsies and nerve specimens collected from sacrificed animals were examined for intraepidermal nerve fiber (IENF) density assessment and nerve morphology/morphometry. Blood and liver samples were collected for targeted metabolomics analysis.

RESULTS

At the end of treatment, the neurophysiological studies revealed a reduction in sensory nerve action potential amplitude (p < .05) in the caudal nerve of young PTX-animals, and in both the digital and caudal nerve of adult PTX-animals (p < .05). A significant decrease in the mechanical threshold was observed only in young PTX-animals (p < .001), but not in adult PTX-ones. Nevertheless, both young and adult PTX-rats had reduced IENF density (p < .0001), which persisted at the end of follow-up period. Targeted metabolomics analysis showed significant differences in the plasma metabolite profiles between PTX-animals developing peripheral neuropathy and age-matched controls, with triglycerides, diglycerides, acylcarnitines, carnosine, long chain ceramides, sphingolipids, and bile acids playing a major role in the response to PTX administration.

INTERPRETATION

Our study identifies for the first time multiple related metabolic axes involved in PTX-induced peripheral neurotoxicity, and suggests age-related differences in CIPN manifestations and in the metabolic profile.

Toxicometabolomics-based cardiotoxicity evaluation of Thiazolidinedione exposure in human-derived cardiomyocytes

INTRODUCTION

Thiazolidinediones (TZDs), represented by pioglitazone and rosiglitazone, are a class of cost-effective oral antidiabetic agents posing a marginal hypoglycaemia risk. Nevertheless, observations of heart failure have hindered the clinical use of both therapies.

OBJECTIVE

Since the mechanism of TZD-induced heart failure remains largely uncharacterised, this study aimed to explore the as-yet-unidentified mechanisms underpinning TZD cardiotoxicity using a toxicometabolomics approach.

METHODS

The present investigation included an untargeted liquid chromatography-mass spectrometry-based toxicometabolomics pipeline, followed by multivariate statistics and pathway analyses to elucidate the mechanism(s)of TZD-induced cardiotoxicity using AC16 human cardiomyocytes as a model, and to identify the prognostic features associated with such effects.

RESULTS

Acute administration of either TZD agent resulted in a significant modulation in carnitine content, reflecting potential disruption of the mitochondrial carnitine shuttle. Furthermore, perturbations were noted in purine metabolism and amino acid fingerprints, strongly conveying aberrations in cardiac energetics associated with TZD usage. Analysis of our findings also highlighted alterations in polyamine (spermine and spermidine) and amino acid (L-tyrosine and valine) metabolism, known modulators of cardiac hypertrophy, suggesting a potential link to TZD cardiotoxicity that necessitates further research. In addition, this comprehensive study identified two groupings - (i) valine and creatine, and (ii) L-tryptophan and L-methionine - that were significantly enriched in the above-mentioned mechanisms, emerging as potential fingerprint biomarkers for pioglitazone and rosiglitazone cardiotoxicity, respectively.

CONCLUSION

These findings demonstrate the utility of toxicometabolomics in elaborating on mechanisms of drug toxicity and identifying potential biomarkers, thus encouraging its application in the toxicological sciences. (245 words).

Untargeted metabolomics reveals potential health risks associated with chronic exposure to environmentally relevant concentrations of 2-Phenylphenol

Chronic exposure to endocrine-disrupting chemicals through foods of aquatic origin, at levels that are commonly found in the environment, can affect metabolic health and lead to metabolic diseases. One such chemical is 2-phenylphenol (2-PP), a suspected endocrine disruptor that is used extensively in agriculture and industry, and has become a widespread pollutant in aquatic environments. This study evaluated the risk of exposure to 2-PP through foods of aquatic origin from Vembanad Lake, using a Target Hazard Quotient (THQ) and an untargeted metabolomics approach. The study found that 2-PP content was higher in samples from areas with intense industrial, tourism, and agricultural activities. The average concentration of 2-PP in fish, crustaceans, and mollusks from the Vembanad estuary ranged from 0.012 to 0.017 mg/kg. The mean concentration of 2-PP was used to assess the THQ of exposure to the coastal population. The results showed that the THQ value was <1, indicating a low to moderate health risk for both adults and children. Furthermore, an untargeted metabolomics approach using HPLC-Q-Orbitrap MS was used to study the metabolome changes associated with chronic exposure to 2-PP (at the environmentally relevant concentration) over 60 days in the Wistar albino rat model. The findings indicated significant alterations in the phospholipid, fatty acid, sterol lipid, and amino acid profiles, suggesting that chronic exposure to 2-PP at environmentally relevant concentrations could affect purine, phenylalanine, tyrosine, and cholesterol metabolism.

Metabolites and MRI-Derived Markers of AD/ADRD Risk in a Puerto Rican Cohort

Objective

Several studies have examined metabolomic profiles in relation to Alzheimer's disease and related dementia (AD/ADRD) risk; however, few studies have focused on minorities, such as Latinos, or examined Magnetic-Resonance Imaging (MRI)-based outcomes.

Methods

We used multiple linear regression, adjusted for covariates, to examine the association between metabolite concentration and MRI-derived brain age deviation. Metabolites were measured at baseline with untargeted metabolomic profiling (Metabolon, Inc). Brain age deviation (BAD) was calculated at wave 4 (~ 9 years from Boston Puerto Rican Health Study (BPRHS) baseline) as chronologic age, minus MRI-estimated brain age, representing the rate of biological brain aging relative to chronologic age. We also examined if metabolites associated with BAD were similarly associated with hippocampal volume and global cognitive function at wave 4 in the BPRHS.

Results

Several metabolites, including isobutyrylcarnitine, propionylcarnitine, phenylacetylglutamine, phenylacetylcarnitine (acetylated peptides), p-cresol-glucuronide, phenylacetylglutamate, and trimethylamine N-oxide (TMAO) were inversely associated with brain age deviation. Taurocholate sulfate, a bile salt, was marginally associated with better brain aging. Most metabolites with negative associations with brain age deviation scores also were inversely associations with hippocampal volumes and wave 4 cognitive function.

Conclusion

The metabolites identifiedin this study are generally consistent with prior literature and highlight the role of BCAA, TMAO and microbially derived metabolites in cognitive decline.

Dysregulation of acyl carnitines, pentose phosphate pathway and arginine and ornithine metabolism are associated with decline in intrinsic capacity in Chinese older adults

BACKGROUND

Intrinsic capacity is the combination of individual physical and mental abilities, reflecting the aging degree of the older adults. However, the mechanisms and metabolic characteristics of the decline in intrinsic capacity are still unclear.

AIMS

To identify metabolic signatures and associated pathways of decline in intrinsic capacity based on the metabolite features.

METHODS

We recruited 70 participants aged 77.19 ± 8.31 years. The five domains of intrinsic capacity were assessed by Short Physical Performance Battery (for mobility), Montreal cognition assessment (for cognition), 30-Item Geriatric Depression Scale (for psychology), self-reported hearing/visual impairment (for sensory) and Nutritional risk screening (for vitality), respectively. The serum samples of participants were analyzed by liquid chromatography-mass spectrometry-based metabolomics, followed by metabolite set enrichment analysis and metabolic pathway analysis.

RESULTS

There were 50 participants with a decline in intrinsic capacity in at least one of the domains. A total of 349 metabolites were identified from their serum samples. Overall, 24 differential metabolites, 5 metabolite sets and 13 pathways were associated with the decline in intrinsic capacity.

DISCUSSION

Our results indicated that decline in intrinsic capacity had unique metabolomic profiles.

CONCLUSION

The specific change of acyl carnitines was observed to be a feature of decline in intrinsic capacity. Dysregulation of the pentose phosphate pathway and of arginine and ornithine metabolism was strongly associated with the decline in intrinsic capacity.

ACOD1 deficiency offers protection in a mouse model of diet-induced obesity by maintaining a healthy gut microbiota

Aconitate decarboxylase 1 (ACOD1) is the enzyme synthesizing itaconate, an immuno-regulatory metabolite tuning host-pathogen interactions. Such functions are achieved by affecting metabolic pathways regulating inflammation and microbe survival. However, at the whole-body level, metabolic roles of itaconate remain largely unresolved. By using multiomics-integrated approaches, here we show that ACOD1 responds to high-fat diet consumption in mice by promoting gut microbiota alterations supporting metabolic disease. Genetic disruption of itaconate biosynthesis protects mice against obesity, alterations in glucose homeostasis and liver metabolic dysfunctions by decreasing meta-inflammatory responses to dietary lipid overload. Mechanistically, fecal metagenomics and microbiota transplantation experiments demonstrate such effects are dependent on an amelioration of the intestinal ecosystem composition, skewed by high-fat diet feeding towards obesogenic phenotype. In particular, unbiased fecal microbiota profiling and axenic culture experiments point towards a primary role for itaconate in inhibiting growth of Bacteroidaceae and Bacteroides, family and genus of Bacteroidetes phylum, the major gut microbial taxon associated with metabolic health. Specularly to the effects imposed by Acod1 deficiency on fecal microbiota, oral itaconate consumption enhances diet-induced gut dysbiosis and associated obesogenic responses in mice. Unveiling an unrecognized role of itaconate, either endogenously produced or exogenously administered, in supporting microbiota alterations underlying diet-induced obesity in mice, our study points ACOD1 as a target against inflammatory consequences of overnutrition.

Time-Efficient, High-Resistance Inspiratory Muscle Strength Training Increases Exercise Tolerance in Midlife and Older Adults

PURPOSE

This study aimed to determine if time-efficient, high-resistance inspiratory muscle strength training (IMST), comprising 30 inhalation-resisted breaths per day, improves cardiorespiratory fitness, exercise tolerance, physical function, and/or regional body composition in healthy midlife and older adults.

METHODS

We performed a double-blind, randomized, sham-controlled clinical trial (NCT03266510) testing 6 wk of IMST (30 breaths per day, 6 d·wk -1 , 55%-75% maximal inspiratory pressure) versus low-resistance sham training (15% maximal inspiratory pressure) in healthy men and women 50-79 yr old. Subjects performed a graded treadmill exercise test to exhaustion, physical performance battery (e.g., handgrip strength, leg press), and body composition testing (dual x-ray absorptiometry) at baseline and after 6 wk of training.

RESULTS

Thirty-five participants (17 women, 18 men) completed high-resistance IMST ( n = 17) or sham training ( n = 18). Cardiorespiratory fitness (V̇O 2peak ) was unchanged, but exercise tolerance, measured as treadmill exercise time during a graded exercise treadmill test, increased with IMST (baseline, 539 ± 42 s; end intervention, 606 ± 42 s; P = 0.01) but not sham training (baseline, 562 ± 39 s; end intervention, 553 ± 38 s; P = 0.69). IMST increased peak RER (baseline, 1.09 ± 0.02; end intervention, 1.13 ± 0.02; P = 0.012), peak ventilatory efficiency (baseline, 25.2 ± 0.8; end intervention, 24.6 ± 0.8; P = 0.036), and improved submaximal exercise economy (baseline, 23.5 ± 1.1 mL·kg -1 ⋅min -1 ; end intervention, 22.1 ± 1.1 mL·kg -1 ⋅min -1 ; P < 0.001); none of these factors were altered by sham training (all P > 0.05). Changes in plasma acylcarnitines (targeted metabolomics analysis) were consistently positively correlated with changes in exercise tolerance after IMST but not sham training. IMST was associated with regional increases in thorax lean mass (+4.4%, P = 0.06) and reductions in trunk fat mass (-4.8%, P = 0.04); however, peripheral muscle strength, muscle power, dexterity, and mobility were unchanged.

CONCLUSIONS

These data suggest that high-resistance IMST is an effective, time-efficient lifestyle intervention for improving exercise tolerance in healthy midlife and older adults.

Effect of in utero and lactational exposure to a thyroid hormone system disrupting chemical on mouse metabolome and brain transcriptome

Mice were exposed to a low dose of the model thyroid hormone disruptor, propylthiouracil. Although this had only a modest effect on maternal thyroid hormones production, postnatal analysis of the pups' plasma by mass spectrometry and the brain striatum by RNA sequencing gave evidence of low lasting changes that could reflect an adverse effect on neurodevelopment. Overall, these methods proved to be sensitive enough to detect minor disruptions of thyroid hormone signalling in vivo.

SERPINB3-MYC axis induces the basal-like/squamous subtype and enhances disease progression in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) exhibits distinct molecular subtypes: classical/progenitor and basal-like/squamous. Our study aimed to identify genes contributing to the development of the basal-like/squamous subtype, known for its aggressiveness. Transcriptome analyses revealed consistent upregulation of SERPINB3 in basal-like/squamous PDAC, correlating with reduced patient survival. SERPINB3 transgene expression in PDAC cells enhanced in vitro invasion and promoted lung metastasis in a mouse PDAC xenograft model. Metabolome analyses unveiled a metabolic signature linked to both SERPINB3 and the basal-like/squamous subtype, characterized by heightened carnitine/acylcarnitine and amino acid metabolism, associated with poor prognosis in patients with PDAC and elevated cellular invasiveness. Further analysis uncovered that SERPINB3 inhibited the cysteine protease calpain, a key enzyme in the MYC degradation pathway, and drove basal-like/squamous subtype and associated metabolic reprogramming through MYC activation. Our findings indicate that the SERPINB3-MYC axis induces the basal-like/squamous subtype, proposing SERPINB3 as a potential diagnostic and therapeutic target for this variant.

Sex-Specific Perturbation of Systemic Lipidomic Profile in Newborn Lambs Impacted by Prenatal Testosterone Excess

Gestational hyperandrogenism adversely impacts offspring health. Using an ovine model, we found that prenatal testosterone (T) excess adversely affects growth and cardiometabolic outcomes in female offspring and produces sex-specific effects on fetal myocardium. Since lipids are essential to cardiometabolic function, we hypothesized that prenatal T excess leads to sex-specific disruptions in lipid metabolism at birth. Shotgun lipidomics was performed on the plasma samples collected 48 hours after birth from female (F) and male (M) lambs of control (C) and (T) sheep (CF = 4, TF = 7, CM = 5, TM = 10) and data were analyzed by univariate analysis, multivariate dimensionality reduction modeling followed by functional enrichment, and pathway analyses. Biosynthesis of phosphatidylserine was the major pathway responsible for sex differences in controls. Unsupervised and supervised models showed separation between C and T in both sexes with glycerophospholipids and glycerolipids classes being responsible for the sex differences between C and T. T excess increased cholesterol in females while decreasing phosphatidylcholine levels in male lambs. Specifically, T excess: 1) suppressed the phosphatidylethanolamine N-methyltransferase (PEMT) phosphatidylcholine synthesis pathway overall and in TM lambs as opposed to suppression of carnitine levels overall and TF lambs; and 2) activated biosynthesis of ether-linked (O-)phosphatidylethanolamine and O-phosphatidylcholine from O-diacylglycerol overall and in TF lambs. Higher cholesterol levels could underlie adverse cardiometabolic outcomes in TF lambs, whereas suppressed PEMT pathway in TM lambs could lead to endoplasmic reticulum stress and defective lipid transport. These novel findings point to sex-specific effects of prenatal T excess on lipid metabolism in newborn lambs, a precocial ovine model of translational relevance.

Open access repository-scale propagated nearest neighbor suspect spectral library for untargeted metabolomics

Despite the increasing availability of tandem mass spectrometry (MS/MS) community spectral libraries for untargeted metabolomics over the past decade, the majority of acquired MS/MS spectra remain uninterpreted. To further aid in interpreting unannotated spectra, we created a nearest neighbor suspect spectral library, consisting of 87,916 annotated MS/MS spectra derived from hundreds of millions of MS/MS spectra originating from published untargeted metabolomics experiments. Entries in this library, or "suspects," were derived from unannotated spectra that could be linked in a molecular network to an annotated spectrum. Annotations were propagated to unknowns based on structural relationships to reference molecules using MS/MS-based spectrum alignment. We demonstrate the broad relevance of the nearest neighbor suspect spectral library through representative examples of propagation-based annotation of acylcarnitines, bacterial and plant natural products, and drug metabolism. Our results also highlight how the library can help to better understand an Alzheimer's brain phenotype. The nearest neighbor suspect spectral library is openly available for download or for data analysis through the GNPS platform to help investigators hypothesize candidate structures for unknown MS/MS spectra in untargeted metabolomics data.

Database screening as a strategy to identify endogenous candidate metabolites to probe and assess mitochondrial drug toxicity

Adverse drug reactions (ADRs) are considered an inherent risk of medication use, and some ADRs have been associated with off-target drug interactions with mitochondria. Metabolites that reflect mitochondrial function may help identify patients at risk of mitochondrial toxicity. We employed a database strategy to identify candidate mitochondrial metabolites that could be clinically useful to identify individuals at increased risk of mitochondrial-related ADRs. This led to L-carnitine being identified as the candidate mitochondrial metabolite. L-carnitine, its acetylated metabolite, acetylcarnitine and other acylcarnitines are mitochondrial biomarkers used to detect inborn errors of metabolism. We hypothesized that changes in L-carnitine disposition, induced by a "challenge test" of intravenous L-carnitine, could identify mitochondrial-related ADRs by provoking variation in L-carnitine and/or acetylcarnitine blood levels. To test this hypothesis, we induced mitochondrial drug toxicity with clofazimine (CFZ) in a mouse model. Following CFZ treatment, mice received an L-carnitine "challenge test". CFZ-induced changes in weight were consistent with previous work and reflect CFZ-induced catabolism. L-carnitine induced differences in whole blood acetylcarnitine concentrations in a manner that was dependent on CFZ treatment. This supports the usefulness of a database strategy for the discovery of candidate metabolite biomarkers of drug toxicity and substantiates the potential of the L-carnitine "challenge test" as a "probe" to identify drug-related toxicological manifestations.

Association between plasma L-carnitine levels and mitochondrial DNA copy number

Mitochondria are key cytoplasmic organelles in eukaryotic cells that generate adenosine triphosphate (ATP) through the electron transport chain and oxidative phosphorylation. Mitochondrial DNA (mtDNA) copy number (mtDNAcn) is considered a biomarker for both mitochondrial quantity and function as well as cellular oxidative stress level. Previous epidemiologic findings revealed that weight gain, higher body mass index (BMI), smoking, and high insulinemic potential of lifestyle were associated with lower leukocyte mtDNAcn. Carnitines are a group of compounds that play a critical role in energy production. We quantified the associations of plasma L-carnitine levels with leukocyte mtDNAcn. We then examined the association between mtDNAcn and L-carnitine (HMDB0000062) in 538 U.S. men without cancers, diabetes, or cardiovascular disease at blood collection from the Health Professionals Follow-Up Study (HPFS). We found a significant inverse association between L-carnitine and mtDNAcn (ρ = -0.1, P = 0.02). This implies that the carnitine metabolic pathway may be associated with mitochondrial function and oxidative stress.

Comparative Lipidomics and Metabolomics Reveal the Underlying Mechanisms of Taurine in the Alleviation of Nonalcoholic Fatty Liver Disease Using the Aged Laying Hen Model

SCOPE

Aged laying hen is recently suggested as a more attractive animal model than rodent for studying nonalcoholic fatty liver disease (NAFLD) of humans. This study aims to reveal effects and metabolic regulation mechanisms of taurine alleviating NAFLD by using the aged laying hen model.

METHODS AND RESULTS

Liver histomorphology and biochemical indices show 0.02% taurine effectively alleviated fat deposition and liver damage. Comparative liver lipidomics and gene expressions analyses reveal taurine promoted lipolysis, fatty acids oxidation, lipids transport, and reduced oxidative stress in liver. Furthermore, comparative serum metabolomics screen six core metabolites negatively correlated with NAFLD, including linoleic acid, gamma-linolenic acid, pantothenate, L-methionine, 2-methylbutyroylcarnitine, L-carnitine; and two core metabolites positively correlated with NAFLD, including lysophosphatidylcholine (14:0/0:0) and lysophosphatidylcholine (16:0/0:0). Metabolic pathway analysis reveals taurine mainly regulated linoleic acid metabolism, cysteine and methionine metabolism, carnitine metabolism, pantothenic acid and coenzyme A biosynthesis metabolism, and glycerophospholipid metabolism to up-adjust levels of six negatively correlated metabolites and down-adjust two positively correlated metabolites for alleviating NAFLD of aged hens.

CONCLUSION

This study firstly reveals underlying metabolic mechanisms of taurine alleviating NAFLD using the aged hen model, thereby laying the foundation for taurine's application in the prevention of NAFLD in both human and poultry.

Boosting Mitochondrial Biogenesis Diminishes Foam Cell Formation in the Post-Stroke Brain

Following ischemic stroke, the degradation of myelin and other cellular membranes surpasses the lipid-processing capabilities of resident microglia and infiltrating macrophages. This imbalance leads to foam cell formation in the infarct and areas of secondary neurodegeneration, instigating sustained inflammation and furthering neurological damage. Given that mitochondria are the primary sites of fatty acid metabolism, augmenting mitochondrial biogenesis (MB) may enhance lipid processing, curtailing foam cell formation and post-stroke chronic inflammation. Previous studies have shown that the pharmacological activation of the β2-adrenergic receptor (β2-AR) stimulates MB. Consequently, our study sought to discern the effects of intensified β2-AR signaling on MB, the processing of brain lipid debris, and neurological outcome using a mouse stroke model. To achieve this goal, aged mice were treated with formoterol, a long-acting β2-AR agonist, daily for two and eight weeks following stroke. Formoterol increased MB in the infarct region, modified fatty acid metabolism, and reduced foam cell formation. However, it did not reduce markers of post-stroke neurodegeneration or improve recovery. Although our findings indicate that enhancing MB in myeloid cells can aid in the processing of brain lipid debris after stroke, it is important to note that boosting MB alone may not be sufficient to significantly impact stroke recovery.

Reduced glutathione level in the aqueous humor of patients with primary open-angle glaucoma and normal-tension glaucoma

Glaucoma is a leading cause of blindness worldwide in older people. Profiling the aqueous humor, including the metabolites it contains, is useful to understand physiological and pathological conditions in the eye. In the current study, we used mass spectrometry (MS) to characterize the aqueous humor metabolomic profile and biological features of patients with glaucoma. Aqueous humor samples were collected during trabeculectomy surgery or cataract surgery and analyzed with global metabolomics. We included 40 patients with glaucoma (32 with POAG, 8 with NTG) and 37 control subjects in a discovery study. VIP analysis revealed five metabolites that were elevated and three metabolites that were reduced in the glaucoma patients. The identified metabolomic profile had an area under the receiver operating characteristic curve of 0.953. Among eight selected metabolites, the glutathione level was significantly decreased in association with visual field defects. Moreover, in a validation study to confirm the reproducibility of our findings, the glutathione level was reduced in NTG and POAG patients compared with a cataract control group. Our findings demonstrate that aqueous humor profiling can help to diagnose glaucoma and that various aqueous humor metabolites are correlated with clinical parameters in glaucoma patients. In addition, glutathione is clearly reduced in the aqueous humor of glaucoma patients with both IOP-dependent and IOP-independent disease subtypes. These findings indicate that antioxidant agents in the aqueous humor reflect glaucomatous optic nerve damage and that excessive oxidative stress may be involved in the pathogenesis of glaucoma.

Associations between Smoking and Smoking Cessation during Pregnancy and Newborn Metabolite Concentrations: Findings from PRAMS and INSPIRE Birth Cohorts

Newborn metabolite perturbations may identify potential biomarkers or mechanisms underlying adverse, smoking-related childhood health outcomes. We assessed associations between third-trimester smoking and newborn metabolite concentrations using the Tennessee Pregnancy Risk Assessment Monitoring System (PRAMS, 2009-2019) as the discovery cohort and INSPIRE (2012-2014) as the replication cohort. Children were linked to newborn screening metabolic data (33 metabolites). Third-trimester smoking was ascertained from birth certificates (PRAMS) and questionnaires (INSPIRE). Among 8600 and 1918 mother-child dyads in PRAMS and INSPIRE cohorts, 14% and 13% of women reported third-trimester smoking, respectively. Third-trimester smoking was associated with higher median concentrations of free carnitine (C0), glycine (GLY), and leucine (LEU) at birth (PRAMS: C0: adjusted fold change 1.11 [95% confidence interval (CI) 1.08, 1.14], GLY: 1.03 [95% CI 1.01, 1.04], LEU: 1.04 [95% CI 1.03, 1.06]; INSPIRE: C0: 1.08 [95% CI 1.02, 1.14], GLY: 1.05 [95% CI 1.01, 1.09], LEU: 1.05 [95% CI 1.01, 1.09]). Smoking cessation (vs. continued smoking) during pregnancy was associated with lower median metabolite concentrations, approaching levels observed in infants of non-smoking women. Findings suggest potential pathways underlying fetal metabolic programming due to in utero smoke exposure and a potential reversible relationship of cessation.

Pharmacokinetics in Pharmacometabolomics: Towards Personalized Medication

Indiscriminate drug administration may lead to drug therapy results with varying effects on patients, and the proposal of personalized medication can help patients to receive effective drug therapy. Conventional ways of personalized medication, such as pharmacogenomics and therapeutic drug monitoring (TDM), can only be implemented from a single perspective. The development of pharmacometabolomics provides a research method for the realization of precise drug administration, which integrates the environmental and genetic factors, and applies metabolomics technology to study how to predict different drug therapeutic responses of organisms based on baseline metabolic levels. The published research on pharmacometabolomics has achieved satisfactory results in predicting the pharmacokinetics, pharmacodynamics, and the discovery of biomarkers of drugs. Among them, the pharmacokinetics related to pharmacometabolomics are used to explore individual variability in drug metabolism from the level of metabolism of the drugs in vivo and the level of endogenous metabolite changes. By searching for relevant literature with the keyword "pharmacometabolomics" on the two major literature retrieval websites, PubMed and Web of Science, from 2006 to 2023, we reviewed articles in the field of pharmacometabolomics that incorporated pharmacokinetics into their research. This review explains the therapeutic effects of drugs on the body from the perspective of endogenous metabolites and pharmacokinetic principles, and reports the latest advances in pharmacometabolomics related to pharmacokinetics to provide research ideas and methods for advancing the implementation of personalized medication.

METABOLOMIC AND PROTEOMIC CHANGES IN TRAUMA-INDUCED HYPOCALCEMIA

ABSTRACT

Background: Trauma-induced hypocalcemia is common and associated with adverse outcomes, but the mechanisms remain unclear. Thus, we aimed to characterize the metabolomic and proteomic differences between normocalcemic and hypocalcemic trauma patients to illuminate biochemical pathways that may underlie a distinct pathology linked with this clinical phenomenon. Methods: Plasma was obtained on arrival from injured patients at a Level 1 Trauma Center. Samples obtained after transfusion were excluded. Multiple regression was used to adjust the omics data for injury severity and arrival base excess before metabolome- and proteome-wide comparisons between normocalcemic (ionized Ca 2+ > 1.0 mmol/L) and hypocalcemic (ionized Ca 2+ ≤ 1.0 mmol/L) patients using partial least squares-discriminant analysis. OmicsNet and Gene Ontology were used for network and pathway analyses, respectively. Results: Excluding isolated traumatic brain injury and penetrating injury, the main analysis included 36 patients (n = 14 hypocalcemic, n = 22 normocalcemic). Adjusted analyses demonstrated distinct metabolomic and proteomic signatures for normocalcemic and hypocalcemic patients. Hypocalcemic patients had evidence of mitochondrial dysfunction (tricarboxylic acid cycle disruption, dysfunctional fatty acid oxidation), inflammatory dysregulation (elevated damage-associated molecular patterns, activated endothelial cells), aberrant coagulation pathways, and proteolytic imbalance with increased tissue destruction. Conclusions: Independent of injury severity, hemorrhagic shock, and transfusion, trauma-induced hypocalcemia is associated with early metabolomic and proteomic changes that may reflect unique pathology in hypocalcemic trauma patients. This study paves the way for future experiments to investigate mechanisms, identify intervenable pathways, and refine our management of hypocalcemia in severely injured patients.

High-throughput quantitation of amino acids and acylcarnitine in cerebrospinal fluid: identification of PCNSL biomarkers and potential metabolic messengers

Background: Due to the poor prognosis and rising occurrence, there is a crucial need to improve the diagnosis of Primary Central Nervous System Lymphoma (PCNSL), which is a rare type of non-Hodgkin's lymphoma. This study utilized targeted metabolomics of cerebrospinal fluid (CSF) to identify biomarker panels for the improved diagnosis or differential diagnosis of primary central nervous system lymphoma (PCNSL). Methods: In this study, a cohort of 68 individuals, including patients with primary central nervous system lymphoma (PCNSL), non-malignant disease controls, and patients with other brain tumors, was recruited. Their cerebrospinal fluid samples were analyzed using the Ultra-high performance liquid chromatography - tandem mass spectrometer (UHPLC-MS/MS) technique for targeted metabolomics analysis. Multivariate statistical analysis and logistic regression modeling were employed to identify biomarkers for both diagnosis (Dx) and differential diagnosis (Diff) purposes. The Dx and Diff models were further validated using a separate cohort of 34 subjects through logistic regression modeling. Results: A targeted analysis of 45 metabolites was conducted using UHPLC-MS/MS on cerebrospinal fluid (CSF) samples from a cohort of 68 individuals, including PCNSL patients, non-malignant disease controls, and patients with other brain tumors. Five metabolic features were identified as biomarkers for PCNSL diagnosis, while nine metabolic features were found to be biomarkers for differential diagnosis. Logistic regression modeling was employed to validate the Dx and Diff models using an independent cohort of 34 subjects. The logistic model demonstrated excellent performance, with an AUC of 0.83 for PCNSL vs. non-malignant disease controls and 0.86 for PCNSL vs. other brain tumor patients. Conclusion: Our study has successfully developed two logistic regression models utilizing metabolic markers in cerebrospinal fluid (CSF) for the diagnosis and differential diagnosis of PCNSL. These models provide valuable insights and hold promise for the future development of a non-invasive and reliable diagnostic tool for PCNSL.

Stratification of Amniotic Fluid Cells and Amniotic Fluid by Sex Opens Up New Perspectives on Fetal Health

Amniotic fluid is essential for fetus wellbeing and is used to monitor pregnancy and predict fetal outcomes. Sex affects health and medicine from the beginning of life, but knowledge of its influence on cell-depleted amniotic fluid (AF) and amniotic fluid cells (AFCs) is still neglected. We evaluated sex-related differences in AF and in AFCs to extend personalized medicine to prenatal life. AFCs and AF were obtained from healthy Caucasian pregnant women who underwent amniocentesis at the 16th-18th week of gestation for advanced maternal age. In the AF, inflammation biomarkers (TNFα, IL6, IL8, and IL4), malondialdehyde, nitrites, amino acids, and acylcarnitines were measured. Estrogen receptors and cell fate (autophagy, apoptosis, senescence) were measured in AFCs. TNFα, IL8, and IL4 were higher in female AF, whereas IL6, nitrites, and MDA were similar. Valine was higher in male AF, whereas several acylcarnitines were sexually different, suggesting a mitochondrial involvement in establishing sex differences. Female AFCs displayed higher expression of ERα protein and a higher ERα/ERβ ratio. The ratio of LC3II/I, an index of autophagy, was higher in female AFCs, while LC3 gene was similar in both sexes. No significant sex differences were found in the expression of the lysosomal protein LAMP1, while p62 was higher in male AFCs. LAMP1 gene was upregulated in male AFCs, while p62 gene was upregulated in female ones. Finally, caspase 9 activity and senescence linked to telomeres were higher in female AFCs, while caspase 3 and β-galactosidase activities were similar. This study supports the idea that sex differences start very early in prenatal life and influence specific parameters, suggesting that it may be relevant to appreciate sex differences to cover knowledge gaps. This might lead to improving the diagnosis of risk prediction for pregnancy complications and achieving a more satisfactory monitoring of fetus health, even preventing future diseases in adulthood.