Protein Metabolism Research Articles

Genotype–Phenotype Correlation in a Large Cohort of Eastern Sicilian Patients Affected by Phenylketonuria: Newborn Screening Program, Clinical Features, and Follow-Up

Background: Phenylketonuria (PKU) is an autosomal recessive disorder caused by mutations in the phenylalanine hydroxylase (PAH) gene, leading to impaired amino acid metabolism. Early diagnosis through newborn screening (NBS) enables prompt treatment, preventing neurological complications. This study aims to describe the genetic and phenotypic spectrum of PKU and mild hyperphenylalaninemia (m-HPA) in patients diagnosed at the Department of Inborn Errors of Metabolism and Newborn Screening, Hospital G. Rodolico-S. Marco, Catania, over four decades (1987–2023). Materials and Methods: The retrospective analysis included 102 patients with elevated blood phenylalanine (Phe) levels born in Sicily and followed at the Institute. The phenotype evaluation comprised the Phe levels at birth/diagnosis, dietary tolerance, and sapropterin dihydrochloride responsiveness. The dietary compliance and Phe/Tyr ratios were assessed and compared across phenotypic classes and age groups. Results: Of 102 patients, 34 were classified as having classic PKU, 9 as having moderate PKU, 26 as having mild PKU, and 33 as having m-HPA, with a median age of 21.72 years. Common PAH variants included c.1066-11G>A (26/204 alleles), c.782G>A (18/204 alleles), and c.165delT (13/204 alleles). The phenotypes sometimes diverged from the genotype predictions, emphasizing dietary tolerance over the initial Phe levels for classification: m-HPA was statistically associated with a higher dietary tolerance (p < 0.001) compared to the classic, moderate, or mild forms of PKU. Conclusions: This study highlights the importance of large databases (e.g., BioPKU) for phenotype prediction and treatment optimization. Regular assessment of Phe/Tyr ratios is crucial for monitoring adherence and health. Phenotype determination, dietary management, and emerging therapies (Pegvaliase and gene therapy) are key to improving outcomes for PKU patients.

Skeletal muscle disorders as risk factors for type 2 diabetes.

The incidence and prevalence of muscular disorders and of type 2 diabetes (T2D) is increasing and both represent highly significant healthcare problems, both economically and compromising quality of life. Interestingly, skeletal muscle dysfunction and T2D share some commonalities including dysregulated glucose homeostasis, increased oxidative stress, dyslipidemia, and cytokine alterations. Several lines of evidence have hinted to a relationship between skeletal muscle dysfunction and T2D. For instance, T2D affects skeletal muscle morphology, functionality, and overall health through altered protein metabolism, impaired mitochondrial function, and ultimately cell viability. Conversely, humans suffering from myopathies and their experimental models demonstrated increased incidence of T2D through altered muscle glucose disposal function due to abnormal calcium homeostasis, compromised mitochondrial function, dyslipidemia, increased inflammatory cytokines and fiber size alterations and disproportions. Lifestyle modifications are essential for improving and maintaining mobility and metabolic health in individuals suffering from myopathies along with T2D. In this review, we updated current literature evidence on clinical incidence of T2D in inflammatory, mitochondrial, metabolic myopathies, and muscular dystrophies and further discussed the molecular basis of these skeletal muscle disorders leading to T2D.

Metabolomics and transcriptomics analyses revealed overexpression of TaMGD enhances wheat plant heat stress resistance through multiple responses.

Monogalactosyldiacylglycerol (MGDG), as the primary lipid component of thylakoid membranes, has a significant part in plant growth and stress response. The current study employed two transgenic wheat lines (MG1516 and MG1314) overexpressing the MGDG synthase gene (TaMGD) and wild-type cv "JW1" to explore the function of TaMGD in response to high temperature stress during the anthesis stage of wheat. Under high-temperature stress, the overexpressed wheat lines exhibited higher grain weight, increased antioxidant enzyme activity, and lower H2O2 and malondialdehyde contents in leaves. Transcriptomic analysis suggests that overexpression of TaMGD influenced multiple metabolic pathways in response to high-temperature stress, including carbon metabolism, amino acid metabolism, photosynthesis, and lipid-related metabolism. Overall, 146 differentially expressed metabolites (DEMs) were identified in MG1516 and wild-type (WT) under heat stress, with MG1516 exhibiting a higher number of upregulated metabolites, particularly glycolipids, organic acids, and organic oxygen compounds. Furthermore, lipid content and unsaturation analysis revealed that the overexpressing wheat line had a higher lipid content and greater saturation than WT under heat stress. Our findings demonstrate that overexpression of TaMGD in wheat affects multiple metabolic pathways, including photosynthesis, carbon, and amino acid metabolism, in reply to high-temperature stress through the modification of cell membrane lipid content, fatty acid unsaturation and other factors.

Identification of Metabolic Characteristic–Pancreatic Ductal Adenocarcinoma Associations Using Mendelian Randomization and Metabolomics

BackgroundMetabolic reprogramming is increasingly recognized as a crucial factor influencing the development, progression, and prognosis of pancreatic ductal adenocarcinoma (PDAC). Despite this, the potential association of specific metabolic characteristics and PDAC remains ambiguous due to the variability introduced by individual patient differences. In this study, we aimed to find out metabolic pathways that may be associated with the overall survival (OS) of PDAC patients.MethodsWe utilized Mendelian randomization (MR) to assess the associations between 1400 metabolites and metabolite ratios and PDAC. We performed functional annotation and pathway enrichment analysis on both significant metabolites and the shared proteins corresponding to the significant metabolite ratios. Additionally, we analyzed peripheral blood metabolites from 32 PDAC patients to correlate metabolites with clinicopathological features and OS. Functional enrichment analysis was also conducted on the significant metabolites.ResultsOur MR analysis revealed 55 metabolites/metabolite ratios associated with PDAC. Among the top 20 enriched metabolic pathways involving proteins related to significant metabolite ratios, seven were associated with amino acid metabolism, three with carbohydrate metabolism, and two with lipid metabolism. Serum metabolomics of PDAC patients highlighted significant upregulation in pathways related to primary bile acid biosynthesis, as well as taurine and hypotaurine metabolism, which correlated negatively with OS. Conversely, pathways involved in arginine biosynthesis, arginine and proline metabolism, and aminoacyl-tRNA biosynthesis were notably downregulated and positively associated with OS. Both upregulated and downregulated differential metabolites were notably enriched in the pyrimidine metabolism pathway, which was linked to poorer OS. These associations were corroborated by MR analysis.ConclusionThe study provides valuable insights into the metabolic characteristics associated with PDAC, offering a reference point for improving diagnosis and treatment for PDAC.

Effects of Different Ionic Liquids on Microbial Growth and Microbial Communities' Structure of Soil.

Ionic liquids (ILs) are widely used "green solvent" as they have a low vapor pressure and can replace volatile solvents in industry. However, ILs are difficult to biodegrade and are potentially harmful to the environment. This study, herein, investigated the toxicity of three imidazole ILs ([C8MIM]Cl, [C8MIM]Br, and [C8DMIM]Br) towards soil microorganisms. The results showed that the ILs inhibited the growth of soil culturable microorganisms and affected the activity of soil enzyme. In addition, microbial communities' species and abundance in soil were altered. Finally, functional prediction analysis revealed that ILs mainly affected the carbohydrate metabolism and amino acid metabolic processes of the microorganisms. ILs with single methyl substituent had a more pronounced effect than those with double methyl substituents. The study indicates that the use of ILs with double methyl substituents is more environmentally safe, and that the toxicity of ILs should be taken into account in industrial production for the design and production of more environmentally safe types, such as ILs with double methyl substituents.

Molecular responses of Mytilus coruscus hemocytes to lipopolysaccharide and peptidoglycan as revealed by 4D-DIA based quantitative proteomics analysis.

Mytilus are sessile filter feeders that live in close contact with numerous marine microorganisms. Hemocytes, the immunocompetent cells of Mytilus, participate in the immune response in a very efficient manner. Lipopolysaccharide (LPS) and peptidoglycan (PGN) follow specific microbe/pathogen-associated molecular patterns (MAMPs or PAMPs) and are involved in immune stimulation in host cells. This study evaluated the molecular profiles and reactions at protein level of Mytilus hemocytes after stimulation with LPS and PGN. Mytilus coruscus was challenged in vivo with LPS and PGN. The hemocytes were collected after 48 h and analyzed for quantitative proteomics, cell subpopulations, and the free amino acid composition. 4D-DIA technology-based proteomic analysis revealed different protein profiles, as well as different responses at protein level, under either the LPS or PGN challenge. C-type lectins, collagens, and CD151 protein were highly upregulated in LPS-challenged mussels, while phospholipase A2 and dCMP deaminase were highly upregulated in PGN-challenged mussels. Moreover, LPS challenge disrupted dsRNA-mediated translation and stimulated energy-related metabolism, while PGN challenge stimulated proteins involved in the inflammatory response and suppressed amino acid metabolism. In addition, the LPS and PGN challenges differed in their effects on the free amino acid composition and granulocytes ratio of the hemocytes. These findings highlight the different strategies employed by mussel hemocytes in response to different MAMPs, providing insights into the effects of LPS and PGN on Mytilus.

Abnormal microbial amino acid metabolism and activated pathogenesis in scalp with dandruff.

Abnormal microbial amino acid metabolism and activated pathogenesis in scalp with dandruff.

Effects of Lutjanus erythropterus Protein on Depression-like Behavior and Gut Microbiota in Stressed Juvenile Mice.

Lutjanus erythropterus protein (Lep) exhibits anti-inflammatory effects, but its antidepressant activity is unknown. This study used a 44-day chronic unpredictable mild stress (CUMS) model to determine whether Lep has a beneficial effect through the gut-brain axis in 3-week-old male C57BL/6 mice. Gavaging with Lep solution alleviated the depression-like behavior and anxiety symptoms in CUMS growing mice. Administration of Lep decreased serum IL-1β, IL-2, IL-6, and TNF-α levels and restored colonic mucosal damage. In addition, Lep improved the disturbance of 5-hydroxytryptamine (5-HT) secretion in the gut-brain axis. Pearson analysis revealed that gut short-chain fatty acid (SCFAs) concentration significantly (p < 0.05) correlated with mucosal damage scores and the depression-like behavior index. Lep was able to prevent the gut SCFA enrichment. Lep upregulated gut Muribaculaceae and downregulated SCFA-producing bacteria by replenishing deficient amino acid (AA) (tryptophan, alanine, aspartate, glutamate) and decreased (p < 0.01) the gene abundance of the AA metabolism pathway of SCFA-producing bacteria, thereby preventing gut SCFA enrichment and alleviating associated depression-like behavior. These findings indicate that Lep could attenuate depression in CUMS juvenile mice via the gut microbiota-SCFA-brain axis.

Influence of Drying Methods on the Morphological Features, Microstructural Properties, and Antioxidant Performance of Floccularia luteovirens: A Metabolomic Analysis.

Floccularia luteovirens (F. luteovirens) has garnered increasing attention as an ingredient in both the pharmaceutical and food industries. Depending on the drying method, the accumulation of metabolites can greatly affect the quality. This research employed an untargeted metabolomics (LC-MS/MS) strategy to elucidate the similarities and differences in the morphological characteristics, microstructure, antioxidant capacity, and metabolic profiles of F. luteovirens subjected to three distinct drying methods: natural air-drying (YG), oven-drying (HG), and vacuum freeze-drying (DG). Our findings indicated that the color of F. luteovirens samples dried using the YG and HG methods was yellow-brown, exhibiting a high degree of browning, whereas the samples processed by the DG method displayed a golden-yellow hue and a desirable fullness. Regarding microstructure, the F. luteovirens samples from the YG and HG methods exhibited small and unevenly distributed pores, in contrast to the samples from the DG method, which were structurally intact and characterized by large inter-tissue pores. The antioxidant activity exhibited by F. luteovirens samples, which were processed using the DG method, was found to be significantly superior compared to the antioxidant activity of samples dried using two other methods. A correlation analysis indicated a significant link between antioxidant capacity and lipid as well as lipid-like molecules. Metabolomic analysis identified 1617 metabolites across 15 superclasses, with lipids, lipid-like molecules, organic acids and derivatives, and organic heterocyclic compounds being the predominant metabolites in F. luteovirens. Furthermore, KEGG enrichment analysis highlighted 20 pathways, indicating that the metabolism of amino acids could be significantly involved in the metabolic processes linked to the drying of F. luteovirens. This research clarifies how different drying techniques impact the metabolites or metabolic pathways of F. luteovirens, identifying the mechanisms that influence its quality and providing a reference for optimizing its processing and storage.

Severe Diabetic Ketoacidosis in Children with Type 1 Diabetes: Ongoing Challenges in Care.

Diabetic ketoacidosis is the most common acute complication in children and adolescents with type 1 diabetes, and contributes significantly to morbidity, mortality, and healthcare burden. This review aims to explore the multifaceted aspects of severe diabetic ketoacidosis in pediatric age, including its epidemiology, pathogenesis, risk factors, complications and emphasizing advances in prevention strategies. Incidence rates vary due to influences from geographic, socioeconomic, cultural and demographic factors. Pathogenesis is linked to insulin deficiency and an excess of counter-regulatory hormones, which disrupt glucose, protein, and lipid metabolism, causing hyperglycemia, ketosis, acidosis, dehydration, and electrolyte imbalances. According to the International Society for Pediatric and Adolescent Diabetes guidelines, severe diabetic ketoacidosis is characterized by a pH < 7.1 or bicarbonate < 5 mmol/L. This condition can lead to a wide range of life-threatening complications, including cerebral edema that represents the leading cause of death. Several prevention strategies, including awareness campaigns, early diagnosis of diabetes, regular monitoring and management, effective insulin therapy, education, access to healthcare and technological assistance, may contribute to reduce the risk of severe diabetic ketoacidosis episodes in children and adolescents.

Cellular Signaling of Amino Acid Metabolism in Prostate Cancer.

Prostate cancer is one of the most common malignancies affecting men worldwide and a leading cause of cancer-related mortality, necessitating a deeper understanding of its underlying biochemical pathways. Similar to other cancer types, prostate cancer is also characterised by aberrantly activated metabolic pathways that support tumour development, such as amino acid metabolism, which is involved in modulating key physiological and pathological cellular processes during the progression of this disease. The metabolism of several amino acids, such as glutamine and methionine, crucial for tumorigenesis, is dysregulated and commonly discussed in prostate cancer. And the roles of some less studied amino acids, such as histidine and glycine, have also been covered in prostate cancer studies. Aberrant regulation of two major signalling pathways, mechanistic target of rapamycin (mTOR) and general amino acid control non-depressible 2 (GCN2), is a key driver of reshaping the amino acid metabolism landscape in prostate cancer. By summarising our current understanding of how amino acid metabolism is modulated in prostate cancer, here, we provide further insights into certain potential therapeutic targets for managing prostate cancer through metabolic interventions.

Drug Repurposing: A Conduit to Unravelling Metabolic Reprogramming for Cancer Treatment.

Metabolic reprogramming is a hallmark of cancer. Distinct and unusual metabolic aberrations occur during tumor development that lead to the growth and development of tumors. Oncogenic signaling pathways eventually converge to regulate three major metabolic pathways in tumor cells i.e., glucose, lipid, and amino acid metabolism. Therefore, identifying and targeting the metabolic nodes of cancer cells can be a promising intervention and therapeutic strategy for patients with malignancies. The long road of new drug discovery for cancer therapy has necessitated relooking alternative strategies such as drug repurposing. Advanced genomic and proteomic technologies for the assessment of cancer-specific biological pathways have led to the discovery of new drug targets, which provide excellent opportunities for drug repurposing. The development of effective, safe, cheaper, and readily available anticancer agents is the need of the hour, and drug repurposing has the potential to break the current drug shortage bottleneck. This review will accordingly cover various metabolic pathways that are aberrant in cancer, and strategies for targeting metabolic reprogramming by using repurposed drugs.

Time-series transcriptome analysis reveals the cascade mechanism of biological processes following the perturbation of the MVA pathway in Salvia miltiorrhiza

Various biological processes are interconnected in plants. Transcription factors (TFs) often act as regulatory hubs to regulate plant growth and responses to stress by integrating various biological pathways. Despite extensive studies on TFs functions in various plant species, our understanding of the details of TFs regulation remains limited. In this study, clonal seedlings of Salvia miltiorrhiza were exposed to specific inhibitors for 12 h. Time-series transcriptome data, sampled hourly, were used to construct co-expression networks and gene regulatory networks (GRNs). Transcriptome dynamic analysis was utilized to capture the gene expression dynamics of various biological processes and decipher the potential molecular mechanisms that regulate these processes. The perturbation results showed the growth and development processes of S.miltiorrhiza were primarily affected at the early stage, whereas stress response-related biological processes were mainly influenced at the later stage. And there was a correlation between the series of key differentially expressed genes in terpenoid biosynthesis pathways and the topological distribution of these pathways. Furthermore, the GRNs based on TFs indicate that TFs play a crucial role in connecting various biological processes. In the cytoplasmic lysate gene regulatory module, SmWRKY48-SmTCP4-SmWRKY28 constituted a regulation hub regulating S.miltiorrhiza responses to perturbation of the MVA pathway. The regulation hub mediated various pathways, including pyruvate metabolism, glycolysis/gluconeogenesis, amino acid metabolism, and ubiquinone and other terpenoid-quinone biosynthesis.Our findings suggest that perturbation of a key biological pathway in S.miltiorrhiza has time-dependent effects on other biological processes. And SmWRKY48-SmTCP4-SmWRKY28 constitutes the regulatory hub in S.miltiorrhiza responses to perturbation of MVA pathway.

Alterations in newborn metabolite patterns with preterm birth and diabetes in pregnancy.

This study examines the influence of prematurity and diabetes (DM) in pregnancy on metabolite patterns at birth, and associations with adiposity development in a prospective cohort. Term and preterm (30-36 weeks gestational age [GA]) infants were enrolled and body composition assessments completed through discharge. Targeted metabolomics was used to assess metabolites in cord or infant blood in the first 2 days. Among 91 infants, 62 were preterm and 27 were exposed to DM. In factor analysis, variation in acylcarnitines' and non-essential amino acids differed by GA and DM exposure and were associated with adiposity at term age. DM-group had 1.95-fold increase in t4-OH-pro (p = 0.003) and 2.14-fold increase in taurine (p = 0.004) compared with non-DM group. Preterm infants had 1.77-fold increase in glycerophospholipid PC aa C32:2 versus term group (p < 0.001). Pathway analysis revealed differences across DM and GA groups in pathways associated with citrulline metabolism, amino acid transport/ synthesis, and fatty acid quantity/transport. In this cohort of infants, there are unique metabolite signatures associated with DM exposure, prematurity, and adiposity development after birth. These markers may reflect early metabolism changes in the developing infant which relate to known risks of adverse growth and cardiometabolic outcomes in this group. In this study of term and preterm infants, diabetes in pregnancy was associated with unique metabolic signatures at birth, including increased expression of metabolites related to protein synthesis and lipid metabolism. Metabolites related to lipid and protein metabolism were associated with adiposity development at term age, including estimated body fat percent, skin fold thickness measures, and arm circumference measures. Unique signatures of metabolites associated with prematurity and exposure to diabetes in pregnancy may reflect early metabolism changes in the developing infant which relate to known risks of adverse growth and cardiometabolic outcomes in this group.

Quantifying liver-toxic responses from dose-dependent chemical exposures using a rat genome-scale metabolic model.

Because the liver plays a vital role in the clearance of exogenous chemical compounds, it is susceptible to chemical-induced toxicity. Animal-based testing is routinely used to assess the hepatotoxic potential of chemicals. While large-scale high-throughput sequencing data can indicate the genes affected by chemical exposures, we need system-level approaches to interpret these changes. To this end, we developed an updated rat genome-scale metabolic model to integrate large-scale transcriptomics data and utilized a chemical structure similarity-based ToxProfiler tool to identify chemicals that bind to specific toxicity targets to understand the mechanisms of toxicity. We used high-throughput transcriptomics data from a 5-day in vivo study where rats were exposed to different non-toxic and hepatotoxic chemicals at increasing concentrations and investigated how liver metabolism was differentially altered between the non-toxic and hepatotoxic chemical exposures. Our analysis indicated that the genes identified via toxicity target analysis and those mapped to the metabolic model showed a distinct gene expression pattern, with the majority showing upregulation for hepatotoxicants compared to non-toxic chemicals. Similarly, when we mapped the metabolic genes at the pathway level, we identified several pathways in carbohydrate, amino acid, and lipid metabolism that were significantly upregulated for hepatotoxic chemicals. Furthermore, using our system-level integration of gene expression data with the rat metabolic model, we could differentiate metabolites in these pathways that were systematically elevated or suppressed due to hepatotoxic versus non-toxic chemicals. Thus, using our combined approach, we were able to identify a set of potential gene signatures that clearly differentiated liver toxic responses from non-toxic chemicals, which helped us identify potential metabolic pathways and metabolites that are systematically associated with the toxicant exposure.

Global transcriptome changes during growth of a novel Penicillium coffeae isolate on the wheat stripe rust fungus, Puccinia striiformis f. sp. tritici.

Wheat stripe rust caused by the fungus Puccinia striiformis f. sp. tritici (Pst) is currently the most destructive disease of wheat. The major control methods which include the deployment of resistant wheat cultivars and application of chemical fungicides are losing efficiency as the fungus evolves. Natural antagonists of Pst may be an avenue for alternative and environmentally sustainable control of the disease in the field. Here we describe a novel fungus found growing on Pst pustules. We identified the fungus as a novel isolate of the plant endophyte Penicillium coffeae. We present a high-quality reference genome and a comparative transcriptomic analysis used to investigate how the fungus deploys its genes during growth amongst Pst spores. The gene content of the P. coffeae ANU01 genome is suggestive of a generalist that makes use of diverse substrates. An abundance of genes related to lipid, amino acid and carbohydrate metabolism indicate that P. coffeae ANU01 has evolved the ability to exploit nutrient stores in Pst urediniospores. P. coffeae ANU01 deploys a number of biosynthetic gene clusters during growth on Pst spores, potentially to inhibit urediniospores germination and halt defence responses. A number of genes encoding carbohydrate active enzymes are also highly upregulated, suggesting targeting and degradation of Pst urediniospores structures. Alongside carbohydrates, P. coffeae ANU01 appears to target spore lipids as a nutrient source, secreting several highly upregulated lipases. Our findings broaden the understanding of growth associated with rust spores as an evolutionary strategy and provide insight into the genes potentially required for this process.

Inherent differential microbial assemblages and functions associated with corals exhibiting different thermal phenotypes.

Certain coral individuals exhibit enhanced resistance to thermal bleaching, yet the specific microbial assemblages and their roles in these phenotypes remain unclear. We compared the microbial communities of thermal bleaching-resistant (TBR) and thermal bleaching-sensitive (TBS) corals using metabarcoding and metagenomics. Our multidomain approach revealed stable distinct microbial compositions between thermal phenotypes. Notably, TBR corals were inherently enriched with microbial eukaryotes, particularly Symbiodiniaceae, linked to photosynthesis, and the biosynthesis of antibiotic and antitumor compounds and glycosylphosphatidylinositol-anchor proteins, crucial for cell wall regulation and metabolite exchange. In contrast, TBS corals were dominated by bacterial metabolic genes related to nitrogen, amino acid, and lipid metabolism. The inherent microbiome differences between TBR and TBS corals, already observed before thermal stress, point to distinct holobiont phenotypes associated to thermal bleaching resistance, offering insights into mechanisms underlying coral response to climate-induced stress.

Emergence of antibiotic-specific Mycobacterium tuberculosis phenotypes during prolonged treatment of mice.

A major challenge in tuberculosis (TB) therapeutics is that antibiotic exposure leads to changes in the physiology of M. tuberculosis (Mtb), which may enable the pathogen to withstand treatment. While antibiotic-treated Mtb has been evaluated in in vitro experiments, it is unclear if and how long-term in vivo treatment with diverse antibiotics with varying treatment-shortening activity (sterilizing activity) affects Mtb physiologic processes differently. Here, we used SEARCH-TB, a pathogen-targeted RNA-sequencing platform, to characterize the Mtb transcriptome in the BALB/c high-dose aerosol infection mouse model following 4 weeks of treatment with three sterilizing and three non-sterilizing antibiotics. Certain transcriptional changes were shared among most antibiotics, including decreased expression of genes associated with protein synthesis and metabolism and the induction of certain genes associated with stress responses. However, the magnitude of this shared response differed between antibiotics. Sterilizing antibiotics rifampin, pyrazinamide, and bedaquiline generated a more quiescent Mtb state than did non-sterilizing antibiotics isoniazid, ethambutol, and streptomycin, as indicated by the decreased expression of genes associated with translation, transcription, secretion of immunogenic proteins, metabolism, and cell wall synthesis. Additionally, we identified distinguishing transcriptional effects specific to each antibiotic, indicating that different mechanisms of action induce distinct patterns in response to cellular injury. In addition to elucidating the Mtb physiologic changes associated with antibiotic stress, this study demonstrates the value of SEARCH-TB as a highly granular pharmacodynamic assay that reveals antibiotic effects that are not apparent based on culture alone.

A murine model of acute and prolonged abdominal sepsis, supported by intensive care, reveals time-dependent metabolic alterations in the heart

BackgroundSepsis-induced cardiomyopathy (SICM) often occurs in the acute phase of sepsis and is associated with increased mortality due to cardiac dysfunction. The pathogenesis remains poorly understood, and no specific treatments are available. Although SICM is considered reversible, emerging evidence suggests potential long-term sequelae. We hypothesized that metabolic and inflammatory cardiac changes, previously observed in acute sepsis as potential drivers of SICM, partially persist in prolonged sepsis.MethodsIn 24-week-old C57BL/6J mice, sepsis was induced by cecal ligation and puncture, followed by intravenous fluid resuscitation, subcutaneous analgesics and antibiotics, and, in the prolonged phase, by parenteral nutrition. Mice were killed after 5 days of sepsis (prolonged sepsis, n = 15). For comparison, we included acutely septic mice killed at 30 h (acute sepsis, n = 15) and healthy controls animals (HC, n = 15). Cardiac tissue was collected for assessment of inflammatory and metabolic markers through gene expression, metabolomic analysis and histological assessment.ResultsIn prolonged sepsis, cardiac expression of IL-1β and IL-6 and macrophage infiltration remained upregulated (p ≤ 0.05). In contrast, tissue levels of Krebs cycle intermediates and adenosine phosphates were normal, whereas NADPH levels were low in prolonged sepsis (p ≤ 0.05). Gene expression of fatty acid transporters and of the glucose transporter Slc2a1 was upregulated in prolonged sepsis (p ≤ 0.01). Lipid staining and glycogen content were elevated in prolonged sepsis together with increased gene expression of enzymes responsible for lipogenesis and glycogen synthesis (p ≤ 0.05). Intermediate glycolytic metabolites (hexose-phosphates, GADP, DHAP) were elevated (p ≤ 0.05), but gene expression of several enzymes for glycolysis and mitochondrial oxidation of pyruvate, fatty-acyl-CoA and ketone bodies to acetyl-CoA were suppressed in prolonged sepsis (p ≤ 0.05). Key metabolic transcription factors PPARα and PGC-1α were downregulated in acute, but upregulated in prolonged, sepsis (p ≤ 0.05 for both). Ketone body concentrations were normal but ketolytic enzymes remained suppressed (p ≤ 0.05). Amino acid metabolism showed mild, mixed changes.ConclusionsOur results suggest myocardial lipid and glycogen accumulation and suppressed mitochondrial oxidation, with a functionally intact Krebs cycle, in the prolonged phase of sepsis, together with ongoing myocardial inflammation. Whether these alterations have functional consequences and predispose to long-term sequelae of SICM needs further research.

Amino acids and CART distinguish A-β+ Ketosis-Prone Diabetes from type 1 and type 2 diabetes during hyperglycemic crises.

When clinically stable, patients with A-β+ Ketosis-Prone Diabetes (KPD) manifest unique markers of amino acid metabolism. Biomarkers differentiating KPD from type 1 (T1D) and type 2 diabetes (T2D) during hyperglycemic crises would accelerate diagnosis and management. Compare serum metabolomics of KPD, T1D and T2D patients during hyperglycemic crises, and utilize Classification and Regression Tree (CART) modeling to distinguish these forms of diabetes. Urban hospital emergency center. Adults with KPD, T1D and T2D during hyperglycemic crises (with or without diabetic ketoacidosis (DKA), and healthy controls. Comparisons of serum metabolite and hormonal profiles, and CART analysis. Group differences in concentrations of amino acids, their metabolites and relationship to glucose counterregulatory hormones; C-peptide cutoffs and analytes to distinguish KPD, T1D and T2D. Concentrations of most amino acids were similar in KPD and T1D and lower compared to T2D (P<0.05). Glucagon and cortisol concentrations were correlated with 3-methylhistidine and blood urea nitrogen in KPD but not in T1D. A C-peptide cutoff of 0.496 ng/mL differentiated T1D from KPD during DKA. CART revealed that a regression model based on the concentrations of β-hydroxybutyrate, C-peptide, glucagon, alpha-keto-β-methylvalerate, cystine and myristoyl-L-carnitine distinguished KPD from T1D and T2D. During DKA, KPD and T1D patients have similarly altered amino acid profiles that differentiate them from T2D patients. Elevated protein catabolic hormones drive altered amino acid metabolism in KPD, rather than insulin deficiency as with T1D. A combination of 6 analytes differentiates KPD from T1D and T2D during hyperglycemic crises.