Combined NMR and LC−DAD-MS Analysis Reveals Comprehensive Metabonomic Variations for Three Phenotypic Cultivars of <i>Salvia Miltiorrhiza</i> Bunge

Metabonomic analysis is an important molecular phenotyping method for understanding plant ecotypic variations and gene functions. Here, we systematically characterized the metabonomic variations associated with three Salvia miltiorrhiza Bunge (SMB) cultivars using the combined NMR and LC−DAD-MS detections in conjunction with multivariate data analysis. Our results indicated that NMR methods were effective to quantitatively detect the abundant plant metabolites including both the primary and secondary metabolites whereas the LC−DAD-MS methods were excellent for selectively detecting the secondary metabolites. We found that the SMB metabonome was dominated by 28 primary metabolites including sugars, amino acids, and carboxylic acids and 4 polyphenolic secondary metabolites, among which N-acetylglutamate, asparate, fumurate, and yunnaneic acid D were reported for the first time in this plant. We also found that three SMB cultivars growing at the same location had significant metabonomic differences in terms of metabolisms of carbohydrates, amino acids, and choline, TCA cycle, and the shikimate-mediated secondary metabolisms. We further found that the same SMB cultivar growing at different locations differed in their metabonome. These results provided important information on the ecotypic dependence of SMB metabonome on the growing environment and demonstrated that the combination of NMR and LC−MS methods was effective for plant metabonomic phenotype analysis

Systemic Responses of Mice to Dextran Sulfate Sodium-Induced Acute Ulcerative Colitis Using ¹H NMR Spectroscopy

The interplay between genetic mutation and environmental factors is believed to contribute to the etiology of inflammatory bowel disease (IBD). While focused attention has been paid to the aforementioned research, time-specific and organ-specific metabolic changes associated with IBD are still lacking. Here, we induced acute ulcerative colitis in mice by providing water containing 3% dextran sulfate sodium (DSS) for 7 days and investigated the metabolic changes of plasma, urine, and a range of biological tissues by employing a ¹H nuclear magnetic resonance (NMR)-based metabonomics approach with complementary information on serum clinical chemistry and histopathology. We found that DSS-induced acute ulcerative colitis leads to significant elevations in the levels of amino acids in plasma and decreased levels in the membrane-related metabolites and a range of nucleotides, nucleobases, and nucleosides in the colon. In addition, acute-colitis-induced elevations in the levels of nucleotides in the liver were observed, accompanied by reduced levels of glucose. DSS-induced acute colitis also resulted in increased levels of oxidized glutathione and attenuated levels of taurine in the spleen. Furthermore, acute colitis resulted in depletion in the levels of gut microbial cometabolites in urine along with an increase in citric acid cycle intermediates. These findings suggest that DSS-induced acute colitis causes a disturbance of lipid and energy metabolism, damage to the colon and liver, a promoted antioxidative and anti-inflammatory response, and perturbed gut microbiotal communities. The information obtained here provided details of the time-dependent and holistic metabolic changes in the development of the DSS-induced acute ulcerative colitis, which could be useful in discovery of novel therapeutic targets for management of IBD

Global Metabolomic Responses of <i>Escherichia coli</i> to Heat Stress

Microbial metabolomic analysis is essential for understanding responses of microorganisms to heat stress. To understand the comprehensive metabolic responses of <i>Escherichia coli</i> to continuous heat stress, we characterized the metabolomic variations induced by heat stress using NMR spectroscopy in combination with multivariate data analysis. We detected 15 amino acids, 10 nucleotides, 9 aliphatic organic acids, 7 amines, glucose and its derivative glucosylglyceric acid, and methanol in the <i>E. coli</i> extracts. Glucosylglyceric acid was reported for the first time in <i>E. coli</i>. We found that heat stress was an important factor influencing the metabolic state and growth process, mainly via suppressing energy associated metabolism, reducing nucleotide biosynthesis, altering amino acid metabolism and promoting osmotic regulation. Moreover, metabolic perturbation was aggravated during heat stress. However, a sign of recovery to control levels was observed after the removal of heat stress. These findings enhanced our understanding of the metabolic responses of <i>E. coli</i> to heat stress and demonstrated the effectiveness of the NMR-based metabolomics approach to study such a complex system

Systemic Metabolic Responses of Broiler Chickens and Piglets to Acute T‑2 Toxin Intravenous Exposure

The aim of this study is to thoroughly investigate the toxicity mechanism of mycotoxin T-2 toxin and to further understand the endogenous metabolic alterations induced by T-2 toxin. To achieve this, a nuclear magnetic resonance (NMR)-based metabonomics approach was used to analyze the metabolic alterations induced by a single intravenous injection of T-2 toxin (0.5 mg/kg of body weight) in piglets and broiler chickens. A range of metabolites in the plasma, liver, kidney, and spleen of broiler chickens and plasma of piglets was changed following T-2 toxin injection. For example, a rapid increase of amino acids together with a significant reduction of glucose and lipid occurred in the plasma of broiler chickens and piglets following T-2 toxin treatment. A significant accumulation of amino acids and modulated nucleotides were detected in the liver, kidney, and spleen of T-2 toxin-treated broiler chickens. These data indicated that T-2 toxin caused endogenous metabolic changes in multiple organs and perturbed various metabolic pathways, including energy, amino acid, and nucleotide metabolism, as well as oxidative stress. We also observed elevated levels of tryptophan in the T-2 toxin-treated broiler chickens, which may explain the reported neurotoxic effects of T-2 toxin. These findings provide important information on the toxicity of T-2 toxin and demonstrate the power of the NMR-based metabonomics approach in exploring the toxicity mechanism of xenobiotics

Global Metabolomic Responses of <i>Escherichia coli</i> to Heat Stress

Microbial metabolomic analysis is essential for understanding responses of microorganisms to heat stress. To understand the comprehensive metabolic responses of <i>Escherichia coli</i> to continuous heat stress, we characterized the metabolomic variations induced by heat stress using NMR spectroscopy in combination with multivariate data analysis. We detected 15 amino acids, 10 nucleotides, 9 aliphatic organic acids, 7 amines, glucose and its derivative glucosylglyceric acid, and methanol in the <i>E. coli</i> extracts. Glucosylglyceric acid was reported for the first time in <i>E. coli</i>. We found that heat stress was an important factor influencing the metabolic state and growth process, mainly via suppressing energy associated metabolism, reducing nucleotide biosynthesis, altering amino acid metabolism and promoting osmotic regulation. Moreover, metabolic perturbation was aggravated during heat stress. However, a sign of recovery to control levels was observed after the removal of heat stress. These findings enhanced our understanding of the metabolic responses of <i>E. coli</i> to heat stress and demonstrated the effectiveness of the NMR-based metabolomics approach to study such a complex system

Human Serum Metabonomic Analysis Reveals Progression Axes for Glucose Intolerance and Insulin Resistance Statuses

Understanding the metabolic basis of glucose intolerances and insulin resistance is essential to facilitate early diagnosis, satisfactory therapies and personalized treatments of type 2 diabetes (T2DM). Here, we analyzed the serum metabolic variations from 231 human participants with normal glucose tolerance (NGT, n = 80, M/F = 34/46, mean age 53 ± 10 years), impaired glucose regulation (IGR, n = 77, M/F = 33/44, mean age 51 ± 10 years) and T2DM (n = 74, M/F = 32/42, mean age 51 ± 9 years) to establish the relationship between the serum metabolite compositions and the development of diabetes. By using the proton nuclear magnetic resonance spectroscopy in conjunction with the multivariate data analysis, we found that the development of both glucose intolerances and insulin resistances are closely correlated with the progressive changes of human serum metabonome. Compared with NGT subjects, the IGR and T2DM participants showed clear dysfunctions of choline metabolism, glucose metabolism, lipid and amino acid metabolisms, and disruptions of TCA cycle. The insulin resistance statuses were closely associated with the serum metabonomic changes in terms of glucose, fatty acid and protein/amino acid metabolisms. We also found greater metabonomic heterogeneity among the populations with T2DM and high insulin resistance status. These findings provide useful information to bridge the gaps in our understandings to the metabolic alterations associated with the progression of glucose intolerances and insulin resistance status

Systems Biological Responses to Chronic Perfluorododecanoic Acid Exposure by Integrated Metabonomic and Transcriptomic Studies

Perfluorocarboxylic acids (PFCAs) have been widely used in consumer and industrial products, such as food packaging, and found in the blood of both humans and wildlife. Although studies showed a high tendency toward biological accumulation and a variety of toxic effects for PFCAs, the mechanistic aspects of their toxicity remain unknown. In present study, we investigated the dosage-dependent metabonomic and transcriptomic responses of male rats to the exposure to perfluorododecanoic acid (PFDoA) over 110 days. Our NMR-based metabonomics results for both liver tissues and serum demonstrated that PFDoA exposure led to hepatic lipidosis, which was characterized by a severe elevation in hepatic triglycerides and a decline in serum lipoprotein levels. The results from transcriptomic changes induced by PFDoA corroborated these results with changes in gene transcript levels associated with fatty acid homeostasis. These results demonstrate that PFDoA induces hepatic steatosis via perturbations to fatty acid uptake, lipogenesis, and fatty acid oxidation. Several serum metabolites exhibited dose-dependences, providing thorough descriptions of changes induced by PFDoA exposure. These observations yielded novel insights regarding the toxicological mechanism of PFCAs at the systems level

Revealing Different Systems Responses to Brown Planthopper Infestation for Pest Susceptible and Resistant Rice Plants with the Combined Metabonomic and Gene-Expression Analysis

Brown planthopper (BPH) is a notorious pest of rice plants attacking leaf sheaths and seriously affecting global rice production. However, how rice plants respond against BPH remains to be fully understood. To understand systems metabolic responses of rice plants to BPH infestation, we analyzed BPH-induced metabolic changes in leaf sheaths of both BPH-susceptible and resistant rice varieties using NMR-based metabonomics and measured expression changes of 10 relevant genes using quantitative real-time PCR. Our results showed that rice metabonome was dominated by more than 30 metabolites including sugars, organic acids, amino acids, and choline metabolites. BPH infestation caused profound metabolic changes for both BPH-susceptible and resistant rice plants involving transamination, GABA shunt, TCA cycle, gluconeogenesis/glycolysis, pentose phosphate pathway, and secondary metabolisms. BPH infestation caused more drastic overall metabolic changes for BPH-susceptible variety and more marked up-regulations for key genes regulating GABA shunt and biosynthesis of secondary metabolites for BPH-resistant variety. Such observations indicated that activation of GABA shunt and shikimate-mediated secondary metabolisms was vital for rice plants to resist BPH infestation. These findings filled the gap of our understandings in the mechanistic aspects of BPH resistance for rice plants and demonstrated the combined metabonomic and qRT-PCR analysis as an effective approach for understanding plant−herbivore interactions

Systems Responses of Rats to Mequindox Revealed by Metabolic and Transcriptomic Profiling

Mequindox is used as an antibiotic drug in livestock; however, its toxicity remains largely unclear. Previously, we investigated metabolic responses of mice to mequindox exposure. In order to evaluate dependences of animal species in response to mequindox insult, we present the metabolic consequences of mequindox exposure in a rat model, by employing the combination of metabonomics and transcriptomics. Metabolic profiling of urine revealed that metabolic recovery is achieved for rats exposed to a low or moderate dose of mequindox, whereas high levels of mequindox exposure trigger liver dysfunction, causing no such recovery. We found that mequindox exposure causes suppression of the tricarboxylic acid cycle and stimulation of glycolysis, which is in contrast to a mouse model previously investigated. In addition, mequindox dosage induces promotion of β-oxidation of fatty acids, which was confirmed by elevated expressions of <i>acox1</i>, <i>hsd17b2</i>, and <i>cpt1a</i> in liver. Furthermore, altered levels of <i>N</i>-methylnicotinate, 1-methylnicotinamide, and glutathione disulfide highlighted the promotion of vitamin B3 antioxidative cycle in rats exposed to mequindox. Moreover, mequindox exposure altered levels of gut microbiotal related co-metabolites, suggesting a perturbation of the gut microflora of the host. Our work provides a comprehensive view of the toxicological effects of mequindox, which is important in the usage of mequindox in animal and human food safety

Systems Responses of Rats to Mequindox Revealed by Metabolic and Transcriptomic Profiling

Mequindox is used as an antibiotic drug in livestock; however, its toxicity remains largely unclear. Previously, we investigated metabolic responses of mice to mequindox exposure. In order to evaluate dependences of animal species in response to mequindox insult, we present the metabolic consequences of mequindox exposure in a rat model, by employing the combination of metabonomics and transcriptomics. Metabolic profiling of urine revealed that metabolic recovery is achieved for rats exposed to a low or moderate dose of mequindox, whereas high levels of mequindox exposure trigger liver dysfunction, causing no such recovery. We found that mequindox exposure causes suppression of the tricarboxylic acid cycle and stimulation of glycolysis, which is in contrast to a mouse model previously investigated. In addition, mequindox dosage induces promotion of β-oxidation of fatty acids, which was confirmed by elevated expressions of <i>acox1</i>, <i>hsd17b2</i>, and <i>cpt1a</i> in liver. Furthermore, altered levels of <i>N</i>-methylnicotinate, 1-methylnicotinamide, and glutathione disulfide highlighted the promotion of vitamin B3 antioxidative cycle in rats exposed to mequindox. Moreover, mequindox exposure altered levels of gut microbiotal related co-metabolites, suggesting a perturbation of the gut microflora of the host. Our work provides a comprehensive view of the toxicological effects of mequindox, which is important in the usage of mequindox in animal and human food safety