Search Results (22)

Objectives: To explore the metabolic changes in zebrafish larvae after infection with Mycobacterium marinum, this study adopted a widely targeted metabolomic approach to analyze the changes in the overall metabolic profiles of zebrafish larvae infected for 5 days. Methods: Data were collected by liquid chromatography–tandem mass spectrometry (LC-MS/MS). Mass spectrometry data were processed using Analyst 1.6.3 and MultiQuant 3.0.3 software, and multivariate statistical analysis was carried out. The KEGG database, HMDB database, and CHEBI database were used to screen and identify differential metabolites, and metabolic pathway enrichment analysis was performed through KEGG pathways. Results: A total of 329 metabolites were detected, among which 61 differential metabolites were screened. Specifically, 41 metabolites, such as kynurenine, isoallolithocholic acid, 2′-deoxyguanosine, indole-3-carboxaldehyde, and L-lactic acid, were downregulated, while 20 metabolites, such as L-palmitoylcarnitine, myristoyl-L-carnitine, dodecanoylcarnitine, 2-isopropyl-malic acid, and 2-methylsuccinic acid, were upregulated. KEGG metabolic pathway enrichment analysis indicated that these differential metabolites were mainly involved in metabolic pathways such as pyrimidine metabolism, nucleotide metabolism, the pentose phosphate pathway, and purine metabolism. Conclusions: This study demonstrated that significant changes occurred in multiple metabolites and metabolic pathways in zebrafish larvae after infection with M. marinum. The research results have improved the understanding of zebrafish as a model organism in the field of Mycobacterium research and laid a solid foundation for subsequent metabolomic-related research using zebrafish. Full article

Background/Objectives: We aimed to identify neonatal circulating metabolic alterations associated with maternal gestational diabetes mellitus (GDM) and to explore whether these altered metabolites could mediate the association of GDM with offspring neurodevelopment. Additionally, we investigated whether neonatal circulating metabolites could improve the prediction of offspring neurodevelopmental disorders over traditional risk factors. Methods: The retrospective cohort study enrolled 1228 mother–child dyads in South China. GDM was diagnosed at 24–28 weeks of gestation. Neonatal circulating amino acids and lipid metabolites (carnitines) were measured from newborn heel blood 3–7 days postpartum. Offspring neurodevelopment was assessed at age 1 year using the Children Neuropsychological and Behavioral Examination Scale. Neurodevelopmental disorders were defined as developmental delay in any domain of the scale. Results: Twenty-one metabolites associated with GDM were identified, consisting of seven amino acids and fourteen carnitines. Among these metabolites, five (glycine, myristicylcarnitine, palmitoylcarnitine, octadecadienoylcarnitine, and 3-hydroxypalmitylcarnitine) mediated the negative association of GDM with offspring neurodevelopment at 1 year (mediation proportions: 3.91–10.66%). Furthermore, six metabolites (glycine, methionine, malonylcarnitine, isovalerylcarnitine, palmitoylcarnitine, and octadecadienoylcarnitine) significantly increased the predictive performance for offspring neurodevelopmental disorders at 1 year over five traditional risk factors including GDM, parity, infant sex, birth weight, and feeding patterns (area under curve: 0.762 vs. 0.718, p = 0.012). Conclusions: GDM was associated with a variety of amino acid and lipid metabolic alterations in neonatal circulation, among which certain metabolites mediated the association of GDM with adverse neurodevelopmental outcomes in offspring. Moreover, some neonatal circulating metabolites may serve as potential biomarkers that improved the prediction of offspring neurodevelopmental disorders over GDM and other traditional risk factors. Full article

Metabolomics has been used extensively to identify crucial molecules and biochemical effects induced by environmental factors. To understand the effects of acute low-salinity stress on Fenneropenaeus chinensis, intestinal histological examination and untargeted metabonomic analysis of F. chinensis were performed after exposure to a salinity of 15 ppt for 3, 7, and 14 d. The histological examination revealed that acute stress resulted in most epithelial cells rupturing, leading to the dispersion of nuclei in the intestinal lumen after 14 days. Metabolomics analysis identified numerous differentially expressed metabolites (DEMs) at different time points after exposure to low-salinity stress, in which some DEMs were steadily downregulated at the early stage of stress and then gradually upregulated. We further screened 14 overlapping DEMs, in which other DEMs decreased significantly during low-salinity stress, apart from L-palmitoylcarnitine and vitamin A, with enrichments in phenylalanine, tyrosine and tryptophan biosynthesis, fatty acid and retinol metabolism, and ABC transporters. ABC transporters exhibit significant abnormalities and play a vital role in low-salinity stress. This study provides valuable insights into the molecular mechanisms underlying the responses of F. chinensis to acute salinity stress. Full article

Pregnancy at an advanced maternal age is considered a risk factor for adverse maternal, fetal, and neonatal outcomes. Here we investigated whether maternal age could be associated with differences in the blood levels of newborn screening (NBS) markers for inborn metabolic disorders on the Recommended Universal Screening Panel (RUSP). Population-level NBS data from screen-negative singleton infants were examined, which included blood metabolic markers and covariates such as age at blood collection, birth weight, gestational age, infant sex, parent-reported ethnicity, and maternal age at delivery. Marker levels were compared between maternal age groups (age range: 1544 years) using effect size analyses, which controlled for differences in group sizes and potential confounding from other covariates. We found that 13% of the markers had maternal age-related differences, including newborn metabolites with either increased (Tetradecanoylcarnitine [C14], Palmitoylcarnitine [C16], Stearoylcarnitine [C18], Oleoylcarnitine [C18:1], Malonylcarnitine [C3DC]) or decreased (3-Hydroxyisovalerylcarnitine [C5OH]) levels at an advanced maternal age (≥35 years, absolute Cohen’s d > 0.2). The increased C3DC levels in this group correlated with a higher false-positive rate in newborn screening for malonic acidemia (p-value < 0.001), while no significant difference in screening performance was seen for the other markers. Maternal age is associated with inborn metabolic differences and should be considered together with other clinical variables in genetic disease screening. Full article

Fetuses with intrauterine growth restriction (FGR) have impaired oxidative and energy metabolism, with persistent consequences on their postnatal development. In this study, we test the hypothesis that FGR skeletal muscle has lower mitochondrial respiration rate and alters the transcriptomic profiles associated with energy metabolism in an ovine model. At late gestation, mitochondrial oxygen consumption rates (OCRs) and transcriptome profiles were evaluated in the skeletal muscle collected from FGR and control fetuses. The ex vivo mitochondrial OCRs were reduced (p < 0.01) in permeabilized FGR soleus muscle compared to the control muscle but only with pyruvate as the metabolic substrate. Mitochondrial OCRs were similar between the FGR and control groups for palmitoyl-carnitine (fatty acid-driven) or pyruvate plus palmitoyl-carnitine metabolic substrates. A total of 2284 genes were differentially expressed in the semitendinosus muscle from growth restricted fetuses (false discovery rate (FDR) ≤ 0.05). A pathway analysis showed that the upregulated genes (FGR compared to control) were overrepresented for autophagy, HIF-1, AMPK, and FOXO signaling pathways (all with an FDR < 0.05). In addition, the expression of genes modulating pyruvate’s entry into the TCA cycle was downregulated, whereas the genes encoding key fatty acid oxidation enzymes were upregulated in the FGR muscle. These findings show that FGR skeletal muscle had attenuated mitochondrial pyruvate oxidation, possibly associated with the inability of pyruvate to enter into the TCA cycle, and that fatty acid oxidation might compensate for the attenuated energy metabolism. The current study provided phenotypic and molecular evidence for adaptive deficiencies in FGR skeletal muscle. Full article

Altered hepatic mitochondrial fatty acid β-oxidation and associated tricarboxylic acid (TCA) cycle activity contributes to lifestyle-related diseases, and circulating biomarkers reflecting these changes could have disease prognostic value. This study aimed to determine hepatic and systemic changes in TCA-cycle-related metabolites upon the selective pharmacologic enhancement of mitochondrial fatty acid β-oxidation in the liver, and to elucidate the mechanisms and potential markers of hepatic mitochondrial activity. Male Wistar rats were treated with 3-thia fatty acids (e.g., tetradecylthioacetic acid (TTA)), which target mitochondrial biogenesis, mitochondrial fatty acid β-oxidation, and ketogenesis predominantly in the liver. Hepatic and plasma concentrations of TCA cycle intermediates and anaplerotic substrates (LC-MS/MS), plasma ketones (colorimetric assay), and acylcarnitines (HPLC-MS/MS), along with associated TCA-cycle-related gene expression (qPCR) and enzyme activities, were determined. TTA-induced hepatic fatty acid β-oxidation resulted in an increased ratio of plasma ketone bodies/nonesterified fatty acid (NEFA), lower plasma malonyl-CoA levels, and a higher ratio of plasma acetylcarnitine/palmitoylcarnitine (C2/C16). These changes were associated with decreased hepatic and increased plasma pyruvate concentrations, and increased plasma concentrations of succinate, malate, and 2-hydroxyglutarate. Expression of several genes encoding TCA cycle enzymes and the malate–oxoglutarate carrier (Slc25a11), glutamate dehydrogenase (Gdh), and malic enzyme (Mdh1 and Mdh2) were significantly increased. In conclusion, the induction of hepatic mitochondrial fatty acid β-oxidation by 3-thia fatty acids lowered hepatic pyruvate while increasing plasma pyruvate, as well as succinate, malate, and 2-hydroxyglutarate. Full article

The Chuanzang black (CB) pig is a new crossbred between Chinese local breeds and modern breeds. Here, we investigated the growth performance, plasma indexes, carcass traits, and meat quality characteristics of conventional DLY (Duroc × Landrace × Yorkshire) crossbreed and CB pigs. The LC-MS/MS-based metabolomics of pork from DLY and CB pigs, as well as the relationship between the changes in the metabolic spectrum and meat quality, were analyzed. In this study, CB pigs presented lower final body weight, average daily gain, carcass weight, and eye muscle area than DLY pigs (p ˂ 0.05). Conversely, the ratio of feed to gain, marbling score, and meat color score of longissimus dorsi (LD) were higher in CB than DLY pigs (p ˂ 0.05). Moreover, psoas major (PM) showed a higher meat color score and a lower cooking loss in CB than DLY pigs (p ˂ 0.05). Interestingly, CB pigs showed lower myofiber diameter and area but higher myofiber density than DLY pigs (p ˂ 0.05). Furthermore, the mRNA expression levels of MyHC I, PPARδ, MEF2C, NFATC1, and AMPKα1 were higher in CB than DLY pigs (p ˂ 0.05). Importantly, a total of 753 metabolites were detected in the two tissues (e.g., psoas major and longissimus dorsi) of CB and DLY pigs, of which the difference in metabolite profiles in psoas major between crossbreeds was greater than that in longissimus dorsi. Specifically, palmitic acid, stearic acid, L-aspartic acid, corticosterone, and tetrahydrocorticosterone were the most relevant metabolites of psoas major meat quality, and tetrahydrocorticosterone, L-Palmitoylcarnitine, arachidic acid, erucic acid, and 13Z,16Z-docosadienoic acid in longissimus dorsi meat were positively correlated with meat quality. The most significantly enriched KEGG pathways in psoas major and longissimus dorsi pork were galactose metabolism and purine metabolism, respectively. These results not only indicated improved meat quality in CB pigs as compared to DLY pigs but may also assist in rational target selection for nutritional intervention or genetic breeding in the swine industry. Full article

Heart-type fatty-acid binding protein (FABP3) is an essential cytosolic lipid transport protein found in cardiomyocytes. FABP3 binds fatty acids (FAs) reversibly and with high affinity. Acylcarnitines (ACs) are an esterified form of FAs that play an important role in cellular energy metabolism. However, an increased concentration of ACs can exert detrimental effects on cardiac mitochondria and lead to severe cardiac damage. In the present study, we evaluated the ability of FABP3 to bind long-chain ACs (LCACs) and protect cells from their harmful effects. We characterized the novel binding mechanism between FABP3 and LCACs by a cytotoxicity assay, nuclear magnetic resonance, and isothermal titration calorimetry. Our data demonstrate that FABP3 is capable of binding both FAs and LCACs as well as decreasing the cytotoxicity of LCACs. Our findings reveal that LCACs and FAs compete for the binding site of FABP3. Thus, the protective mechanism of FABP3 is found to be concentration dependent. Full article

Scientists have long established that fatty acids are the primary substrates for kidney mitochondria. However, to date we still do not know how long-chain and middle-chain fatty acids are oxidized at the mitochondrial level. Our previous research has shown that mitochondria from the heart, brain, and kidney oxidize palmitoylcarnitine at a high rate only in the presence of succinate, glutamate, or pyruvate. In this paper, we report properties of the isolated kidney mitochondria and how malate and succinate affect the oxidation of C16 and C8 acylcarnitines. The isolated kidney mitochondria contain very few endogenous substrates and require malate to oxidize pyruvate, glutamate, and C16 or C8 acylcarnitines. We discovered that with 10 µM of C16 or C8 acylcarnitines, low concentrations of malate (0.2 mM) or succinate (0.5 mM) enhance the States 4 and 3 respiratory rates several times. The highest respiration rates were observed with C16 or C8 acylcarnitines and 5 mM succinate mixtures. Results show that kidney mitochondria, unlike the heart and brain mitochondria, lack the intrinsic inhibition of succinate dehydrogenase. Additionally, results show that the oxidation of fatty acid by the small respirasome’s supercomplex generates a high level of CoQH2, and this makes SDH in the presence of succinate reverse the flow of electrons from CoQH2 to reduce fumarate to succinate. Finally, we report evidence that succinate dehydrogenase is a key mitochondrial enzyme that allows fast oxidation of fatty acids and turns the TCA cycle function from the catabolic to the anabolic and anaplerotic metabolic pathways. Full article

Rest raw materials provide a new source of bioactive dietary ingredients, and this study aimed to determine the health effects of diets with chicken protein hydrolysate (CPH) and chicken oil (CO) generated from deboned chicken meat. Male Wistar rats (n = 56) were divided into seven groups in three predefined sub-experiments to study the effects of protein source (casein, chicken fillet, pork fillet, and CPH), the dose-effect of CPH (50% and 100% CPH), and the effects of combining CPH and CO. Rats were fed high-fat diets for 12 weeks, and casein and chicken fillet were used as controls in all sub-experiments. While casein, chicken-, or pork fillet diets resulted in similar weight gain and plasma lipid levels, the CPH diet reduced plasma total cholesterol. This effect was dose dependent and accompanied with the reduced hepatic activities of acetyl-CoA carboxylase and fatty acid synthase. Further, rats fed combined CPH and CO showed lower weight gain, and higher hepatic mitochondrial fatty acid oxidation, plasma L-carnitine, short-chain acylcarnitines, TMAO, and acetylcarnitine/palmitoylcarnitine. Thus, in male Wistar rats, CPH and CO lowered plasma cholesterol and increased hepatic fatty acid oxidation compared to whole protein diets, pointing to potential health-beneficial bioactive properties of these processed chicken rest raw materials. Full article

Epithelial-to-mesenchymal transition (EMT) is key to tumor aggressiveness, therapy resistance, and immune escape in breast cancer. Because metabolic traits might be involved along the EMT continuum, we investigated whether human breast epithelial cells engineered to stably acquire a mesenchymal phenotype in non-tumorigenic and H-Ras^V12-driven tumorigenic backgrounds possess unique metabolic fingerprints. We profiled mitochondrial–cytosolic bioenergetic and one-carbon (1C) metabolites by metabolomic analysis, and then questioned the utilization of different mitochondrial substrates by EMT mitochondria and their sensitivity to mitochondria-centered inhibitors. “Upper” and “lower” glycolysis were the preferred glucose fluxes activated by EMT in non-tumorigenic and tumorigenic backgrounds, respectively. EMT in non-tumorigenic and tumorigenic backgrounds could be distinguished by the differential contribution of the homocysteine-methionine 1C cycle to the transsulfuration pathway. Both non-tumorigenic and tumorigenic EMT-activated cells showed elevated mitochondrial utilization of glycolysis end-products such as lactic acid, β-oxidation substrates including palmitoyl–carnitine, and tricarboxylic acid pathway substrates such as succinic acid. Notably, mitochondria in tumorigenic EMT cells distinctively exhibited a significant alteration in the electron flow intensity from succinate to mitochondrial complex III as they were highly refractory to the inhibitory effects of antimycin A and myxothiazol. Our results show that the bioenergetic/1C metabolic signature, the utilization rates of preferred mitochondrial substrates, and sensitivity to mitochondrial drugs significantly differs upon execution of EMT in non-tumorigenic and tumorigenic backgrounds, which could help to resolve the relationship between EMT, malignancy, and therapeutic resistance in breast cancer. Full article

Hepatocellular carcinoma (HCC) is the third major cause of cancer-related death worldwide and responds positively to tyrosine kinase inhibitors (TKIs). Dasatinib (Das) is an Src/Abl family kinase and has been successfully utilized in the treatment of various cancers. Cancer cells are known to limit their oxidative phosphorylation to minimize oxidative stress. Palmitoylcarnitine (Pcar) incubation triggers mitochondria-mediated apoptosis in cancer cells by increasing the mitochondrial respiration rate. It stimulates the H₂O₂ production in cancer cells and thus induces oxidative stress. Thus, considering the above observations, the combined effect of Pcar and Das on HepG2, liver cancer cells has been evaluated in the present study. Results demonstrated that combined exposure to Pcar and dasatinib inhibited cell growth, proliferation, and invasion efficiency of cancerous cells more than single-drug treatment. Further, cells undergo membrane depolarization and caspase-dependent apoptosis upon exposure to combined treatment. In addition, in vivo study showed that Pcar and dasatinib treatment reduced the tumor size in mice more significantly than single-drug treatment. Thus, considering the above remarks, combined therapy of Pcar and dasatinib may serve as a potential candidate in the treatment of liver cancer in human and animal tissues. Full article

Hypoxic-ischemic brain injury (HIBI) leads to depletion of ATP, mitochondrial dysfunction, and enhanced oxidant formation. Measurement of acylcarnitines may provide insight into mitochondrial dysfunction. Plasma acylcarnitine levels are altered in neonates after an HIBI, but individual acylcarnitine levels in the brain have not been evaluated. Additionally, it is unknown if plasma acylcarnitines reflect brain acylcarnitine changes. In this study, postnatal day 9 CD1 mouse pups were randomized to HIBI induced by carotid artery ligation, followed by 30 min at 8% oxygen, or to sham surgery and normoxia, with subgroups for tissue collection at 30 min, 24 h, or 72 h after injury (12 animals/group). Plasma, liver, muscle, and brain (dissected into the cortex, cerebellum, and striatum/thalamus) tissues were collected for acylcarnitine analysis by LC-MS. At 30 min after HIBI, acylcarnitine levels were significantly increased, but the differences resolved by 24 h. Palmitoylcarnitine was increased in the cortex, muscle, and plasma, and stearoylcarnitine in the cortex, striatum/thalamus, and cerebellum. Other acylcarnitines were elevated only in the muscle and plasma. In conclusion, although plasma acylcarnitine results in this study mimic those seen previously in humans, our data suggest that the plasma acylcarnitine profile was more reflective of muscle changes than brain changes. Acylcarnitine metabolism may be a target for therapeutic intervention after neonatal HIBI, though the lack of change after 30 min suggests a limited therapeutic window. Full article

There are growing numbers of infants and children living with single-ventricle congenital heart disease (SV). However, cardiac dysfunction and, ultimately, heart failure (HF) are common in the SV population and the ability to predict the progression to HF in SV patients has been limited, primarily due to an incomplete understanding of the disease pathogenesis. Here, we tested the hypothesis that non-invasive circulating metabolomic profiles can serve as novel biomarkers in the SV population. We performed systematic metabolomic and pathway analyses on a subset of pediatric SV non-failing (SVNF) and failing (SVHF) serum samples, compared with samples from biventricular non-failing (BVNF) controls. We determined that serum metabolite panels were sufficient to discriminate SVHF subjects from BVNF subjects, as well as SVHF subjects from SVNF subjects. Many of the identified significantly dysregulated metabolites were amino acids, energetic intermediates and nucleotides. Specifically, we identified pyruvate, palmitoylcarnitine, 2-oxoglutarate and GTP as promising circulating biomarkers that could be used for SV risk stratification, monitoring response to therapy and even as novel targets of therapeutic intervention in a population with few other options. Full article

Mitochondrial dehydrogenases are differentially stimulated by Ca²⁺. Ca²⁺ has also diverse regulatory effects on mitochondrial transporters and other enzymes. However, the consequences of these regulatory effects on mitochondrial oxidative phosphorylation (OxPhos) and ATP production, and the dependencies of these consequences on respiratory substrates, have not been investigated between the kidney and heart despite the fact that kidney energy requirements are second only to those of the heart. Our objective was, therefore, to elucidate these relationships in isolated mitochondria from the kidney outer medulla (OM) and heart. ADP-induced mitochondrial respiration was measured at different CaCl₂ concentrations in the presence of various respiratory substrates, including pyruvate + malate (PM), glutamate + malate (GM), alpha-ketoglutarate + malate (AM), palmitoyl-carnitine + malate (PCM), and succinate + rotenone (SUC + ROT). The results showed that, in both heart and OM mitochondria, and for most complex I substrates, Ca²⁺ effects are biphasic: small increases in Ca²⁺ concentration stimulated, while large increases inhibited mitochondrial respiration. Furthermore, significant differences in substrate- and Ca²⁺-dependent O₂ utilization towards ATP production between heart and OM mitochondria were observed. With PM and PCM substrates, Ca²⁺ showed more prominent stimulatory effects in OM than in heart mitochondria, while with GM and AM substrates, Ca²⁺ had similar biphasic regulatory effects in both OM and heart mitochondria. In contrast, with complex II substrate SUC + ROT, only inhibitory effects on mitochondrial respiration was observed in both the heart and the OM. We conclude that the regulatory effects of Ca²⁺ on mitochondrial OxPhos and ATP synthesis are biphasic, substrate-dependent, and tissue-specific. Full article