Integrative Molecular Phenotyping
INTEGRATIVE MOLECULAR
PHENOTYPING
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY
DEPARTMENT OF MEDICAL
BIOCHEMISTRY AND BIOPHYSICS
WHEELOCK LABORATORY

PubMed

Ammonium accumulation and chemokine decrease in culture media of Gcdh-/- 3D reaggregated brain cell cultures.

Fri, 08/11/2019 - 14:01
Related Articles Ammonium accumulation and chemokine decrease in culture media of Gcdh-/- 3D reaggregated brain cell cultures. Mol Genet Metab. 2019 04;126(4):416-428 Authors: Cudré-Cung HP, Remacle N, do Vale-Pereira S, Gonzalez M, Henry H, Ivanisevic J, Schmiesing J, Mühlhausen C, Braissant O, Ballhausen D Abstract Glutaric Aciduria type I (GA-I) is caused by mutations in the GCDH gene. Its deficiency results in accumulation of the key metabolites glutaric acid (GA) and 3-hydroxyglutaric acid (3-OHGA) in body tissues and fluids. Present knowledge on the neuropathogenesis of GA-I suggests that GA and 3-OHGA have toxic properties on the developing brain. We analyzed morphological and biochemical features of 3D brain cell aggregates issued from Gcdh-/- mice at two different developmental stages, day-in-vitro (DIV) 8 and 14, corresponding to the neonatal period and early childhood. We also induced a metabolic stress by exposing the aggregates to 10 mM l-lysine (Lys). Significant amounts of GA and 3-OHGA were detected in Gcdh-/- aggregates and their culture media. Ammonium was significantly increased in culture media of Gcdh-/- aggregates at the early developmental stage. Concentrations of GA, 3-OHGA and ammonium increased significantly after exposure to Lys. Gcdh-/- aggregates manifested morphological alterations of all brain cell types at DIV 8 while at DIV 14 they were only visible after exposure to Lys. Several chemokine levels were significantly decreased in culture media of Gcdh-/- aggregates at DIV 14 and after exposure to Lys at DIV 8. This new in vitro model for brain damage in GA-I mimics well in vivo conditions. As seen previously in WT aggregates exposed to 3-OHGA, we confirmed a significant ammonium production by immature Gcdh-/- brain cells. We described for the first time a decrease of chemokines in Gcdh-/- culture media which might contribute to brain cell injury in GA-I. PMID: 30686684 [PubMed - indexed for MEDLINE]

Metabolic Response of the Immature Right Ventricle to Acute Pressure Overloading.

Fri, 08/11/2019 - 14:01
Related Articles Metabolic Response of the Immature Right Ventricle to Acute Pressure Overloading. J Am Heart Assoc. 2018 05 30;7(11): Authors: Kajimoto M, Nuri M, Isern NG, Robillard-Frayne I, Des Rosiers C, Portman MA Abstract BACKGROUND: Surgical palliation or repair of complex congenital heart disease in early infancy can produce right ventricular (RV) pressure overload, often leading to acute hemodynamic decompensation. The mechanisms causing this acute RV dysfunction remain unclear. We tested the hypothesis that the immature right ventricle lacks the ability to modify substrate metabolism in order to meet increased energy demands induced by acute pressure overloading. METHODS AND RESULTS: Twenty-two infant male mixed breed Yorkshire piglets were randomized to a sham operation (Control) or pulmonary artery banding yielding >2-fold elevation over baseline RV systolic pressure. We used carbon 13 (13C)-labeled substrates and proton nuclear magnetic resonance to assess RV energy metabolism. [Phosphocreatine]/[ATP] was significantly lower after pulmonary artery banding. [Phosphocreatine]/[ATP] inversely correlated with energy demand indexed by maximal sustained RV systolic pressure/left ventricular systolic pressure. Fractional contributions of fatty acids to citric acid cycle were significantly lower in the pulmonary artery banding group than in the Control group (medium-chain fatty acids; 14.5±1.6 versus 8.2±1.0%, long-chain fatty acids; 9.3±1.5 versus 5.1±1.1%). 13C-flux analysis showed that flux via pyruvate decarboxylation did not increase during RV pressure overloading. CONCLUSIONS: Acute RV pressure overload yielded a decrease in [phosphocreatine]/[ATP] ratio, implying that ATP production did not balance the increasing ATP requirement. Relative fatty acids oxidation decreased without a reciprocal increase in pyruvate decarboxylation. The data imply that RV inability to adjust substrate oxidation contributes to energy imbalance, and potentially to contractile failure. The data suggest that interventions directed at increasing RV pyruvate decarboxylation flux could ameliorate contractile dysfunction associated with acute pressure overloading. PMID: 29848498 [PubMed - indexed for MEDLINE]

metabolomics; +56 new citations

Thu, 07/11/2019 - 19:49
56 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results: metabolomics These pubmed results were generated on 2019/11/07PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

metabolomics; +41 new citations

Tue, 05/11/2019 - 13:27
41 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results: metabolomics These pubmed results were generated on 2019/11/05PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

metabolomics; +69 new citations

Mon, 04/11/2019 - 22:22
69 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results: metabolomics These pubmed results were generated on 2019/11/04PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

metabolomics; +52 new citations

Sat, 02/11/2019 - 13:01
52 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results: metabolomics These pubmed results were generated on 2019/11/02PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

metabolomics; +48 new citations

Fri, 01/11/2019 - 18:55
48 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results: metabolomics These pubmed results were generated on 2019/11/01PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

metabolomics; +17 new citations

Thu, 31/10/2019 - 12:35
17 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results: metabolomics These pubmed results were generated on 2019/10/31PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

metabolomics; +20 new citations

Wed, 30/10/2019 - 12:22
20 new pubmed citations were retrieved for your search. Click on the search hyperlink below to display the complete search results: metabolomics These pubmed results were generated on 2019/10/30PubMed comprises more than millions of citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

Two Is Better Than One: Studying Ustilago bromivora-Brachypodium Compatibility by Using a Hybrid Pathogen.

Tue, 29/10/2019 - 18:12
Related Articles Two Is Better Than One: Studying Ustilago bromivora-Brachypodium Compatibility by Using a Hybrid Pathogen. Mol Plant Microbe Interact. 2019 Oct 28;:MPMI05190148R Authors: Bosch J, Czedik-Eysenberg A, Hastreiter M, Khan M, Güldener U, Djamei A Abstract Pathogenic fungi can have devastating effects on agriculture and health. One potential challenge in dealing with pathogens is the possibility of a host jump (i.e., when a pathogen infects a new host species). This can lead to the emergence of new diseases or complicate the management of existing threats. We studied host specificity by using a hybrid fungus formed by mating two closely related fungi: Ustilago bromivora, which normally infects Brachypodium spp., and U. hordei, which normally infects barley. Although U. hordei was unable to infect Brachypodium spp., the hybrid could. These hybrids also displayed the same mating-type bias that had been observed in U. bromivora and provide evidence of a dominant spore-killer-like system on the sex chromosome of U. bromivora. By analyzing the genomic composition of 109 hybrid strains, backcrossed with U. hordei over four generations, we identified three regions associated with infection on Brachypodium spp. and 75 potential virulence candidates. The most strongly associated region was located on chromosome 8, where seven genes encoding predicted secreted proteins were identified. The fact that we identified several regions relevant for pathogenicity on Brachypodium spp. but that none were essential suggests that host specificity, in the case of U. bromivora, is a multifactorial trait which can be achieved through different subsets of virulence factors. PMID: 31657673 [PubMed - as supplied by publisher]

Iron toxicity-induced physiological and metabolite profile variations among tolerant and sensitive rice varieties.

Tue, 29/10/2019 - 18:12
Related Articles Iron toxicity-induced physiological and metabolite profile variations among tolerant and sensitive rice varieties. Plant Signal Behav. 2019 Oct 28;:1682829 Authors: Turhadi T, Hamim H, Ghulamahdi M, Miftahudin M Abstract Iron toxicity stress causes physiological and metabolic changes in rice and other plants. To date, there is little information about the metabolite profile of rice under Fe toxicity conditions. In fact, metabolite has a contribution to the physiological condition of plants. Plant metabolomics is a study of low-molecular weight metabolites in plants under certain conditions. The objective of the research was to investigate physiological and metabolic changes in rice under Fe toxicity stress. Two-week-old seedlings of four rice varieties with various Fe toxicity tolerance levels were stressed hydroponically with 400 ppm FeSO4.7H2O for 10 d. Numerous physiological characters were observed and untargeted metabolomic analysis was carried out using gas chromatography-mass spectrophotometry (GC-MS). The results showed Fe toxicity induced physiological and metabolite variation in rice. By comparing the metabolites synthesized in Fe toxicity-stressed plants with control plants, it showed that elaidic acid, linoleic acid, and linolenic acid could be as metabolite marker candidates for rice response to Fe toxicity stress. When plants exposed to Fe toxicity stress, elaidic acid increased, whereas linoleic- and linolenic acid decreased. The alteration of fatty acid composition in the root and shoot suggests the alteration of metabolites is one of the tolerance strategies of rice to Fe toxicity stress. This finding offers an insight about the tolerance strategies of rice under Fe toxicity stress related to the maintenance process of the cell membranes during this stress. The genes underlying biosynthesis of the fatty acid could be a target of future research on responsible genes for Fe toxicity tolerance in rice. PMID: 31657655 [PubMed - as supplied by publisher]

Tear Proteins Calcium binding protein A4 (S100A4) and Prolactin Induced Protein (PIP) are Potential Biomarkers for Thyroid Eye Disease.

Tue, 29/10/2019 - 18:12
Related Articles Tear Proteins Calcium binding protein A4 (S100A4) and Prolactin Induced Protein (PIP) are Potential Biomarkers for Thyroid Eye Disease. Sci Rep. 2018 11 16;8(1):16936 Authors: Chng CL, Seah LL, Yang M, Shen SY, Koh SK, Gao Y, Deng L, Tong L, Beuerman RW, Zhou L Abstract There are no reliable biomarkers to predict thyroid eye disease (TED) in patients with autoimmune thyroid disease (AITD) currently. Several evidences support the involvement of the lacrimal gland in TED. The aim of our study was to quantitatively correlate the changes in tear protein profile with increasing severity of TED. Tear samples were collected from four groups of patients; AITD without TED (AITD), AITD with mild TED (mild TED), AITD with severe TED (severe TED) and normal controls. A total of 72 patients were recruited for the study. In discovery phase, isobaric tags for relative and absolute quantification (iTRAQ) 4-plex was used for quantitative proteomics analysis. For verification of results from discovery phase, sequential window acquisition of all theoretical fragment ion spectra (SWATH) was used to analyze an independent cohort from normal controls, AITD, mild TED and severe TED. Two proteins, S100A4 and PIP showed consistent dysregulation trends in the discovery and validation phase experiments. Our study demonstrated the differences in tear proteome across the spectrum of different severity and activity of TED in patients with AITD. Two tear proteins, S100A4 and PIP may serve as potential biomarkers to predict progression to severe TED in patients with AITD. PMID: 30446693 [PubMed - indexed for MEDLINE]

Differential Effects of a Glucagon-Like Peptide 1 Receptor Agonist in Non-Alcoholic Fatty Liver Disease and in Response to Hepatectomy.

Tue, 29/10/2019 - 18:12
Related Articles Differential Effects of a Glucagon-Like Peptide 1 Receptor Agonist in Non-Alcoholic Fatty Liver Disease and in Response to Hepatectomy. Sci Rep. 2018 11 07;8(1):16461 Authors: Valdecantos MP, Ruiz L, Pardo V, Castro-Sanchez L, García-Monzón C, Lanzón B, Rupérez J, Barbas C, Naylor J, Trevaskis JL, Grimsby J, Rondinone CM, Valverde ÁM Abstract Non-alcoholic fatty liver disease (NAFLD) is associated with post-operative liver failure (PLF) and impaired liver regeneration. We investigated the effects of a glucagon-like peptide-1 (GLP-1) receptor agonist on NAFLD, PLF and liver regeneration in mice fed chow diet or methionine/choline-deficient diet (MCD) or high fat diet (HFD). Fc-GLP-1 decreased transaminases, reduced intrahepatic triglycerides (TG) and improved MCD-induced liver dysfuction. Macrophage/Kupffer cell-related markers were also reduced although Fc-GLP-1 increased expression of genes related to natural killer (NK), cytotoxic T lymphocytes and hepatic stellate cell (HSC) activation. After partial hepatectomy (PH), survival rates increased in mice receiving Fc-GLP-1 on chow or MCD diet. However, the benefit of Fc-GLP-1 on NASH-like features was attenuated 2 weeks post-PH and liver mass restoration was not improved. At this time-period, markers of NK cells and cytotoxic T lymphocytes were further elevated in Fc-GLP-1 treated mice. Increased HSC related gene expression in livers was observed together with decreased retinyl ester content and increased retinal and retinoic acid, reflecting HSC activation. Similar effects were found in mice fed HFD receiving Fc-GLP-1. Our results shed light on the differential effects of a long-acting GLP-1R agonist in improving NAFLD and PLF, but not enhancing liver regeneration in mice. PMID: 30405191 [PubMed - indexed for MEDLINE]

Metabolomic Profile Predicts Development of Microalbuminuria in Individuals with Type 1 Diabetes.

Tue, 29/10/2019 - 18:12
Related Articles Metabolomic Profile Predicts Development of Microalbuminuria in Individuals with Type 1 Diabetes. Sci Rep. 2018 09 14;8(1):13853 Authors: Haukka JK, Sandholm N, Forsblom C, Cobb JE, Groop PH, Ferrannini E Abstract Elevated urinary albumin excretion (microalbuminuria) is an early marker of diabetic nephropathy, but there is an unmet need for better biomarkers that capture the individuals at risk with higher accuracy and earlier than the current markers do. We performed an untargeted metabolomic study to assess baseline differences between individuals with type 1 diabetes who either developed microalbuminuria or remained normoalbuminuric. A total of 102 individuals progressed to microalbuminuria during a median follow-up of 3.2 years, whereas 98 sex-, age- and body mass index (BMI) matched non-progressors remained normoalbuminuric during a median follow-up of 7.1 years. Metabolomic screening identified 1,242 metabolites, out of which 111 differed significantly between progressors and non-progressors after adjustment for age of diabetes onset, baseline glycosylated hemoglobin A1c (HbA1c), and albumin excretion rate (AER). The metabolites that predicted development of microalbumiuria included several uremic toxins and carnitine metabolism related molecules. Iterative variable selection indicated erythritol, 3-phenylpropionate, and N-trimethyl-5-aminovalerate as the best set of variables to predict development of microalbuminuria. A metabolomic index based on these metabolites improved the prediction of incident microalbuminuria on top of the clinical variables age of diabetes onset, baseline HbA1c and AER (ROCAUC = 0.842 vs 0.797), highlighting their ability to predict early-phase diabetic nephropathy. PMID: 30217994 [PubMed - indexed for MEDLINE]

Heterologous production of the widely used natural food colorant carminic acid in Aspergillus nidulans.

Tue, 29/10/2019 - 18:12
Related Articles Heterologous production of the widely used natural food colorant carminic acid in Aspergillus nidulans. Sci Rep. 2018 08 27;8(1):12853 Authors: Frandsen RJN, Khorsand-Jamal P, Kongstad KT, Nafisi M, Kannangara RM, Staerk D, Okkels FT, Binderup K, Madsen B, Møller BL, Thrane U, Mortensen UH Abstract The natural red food colorants carmine (E120) and carminic acid are currently produced from scale insects. The access to raw material is limited and current production is sensitive to fluctuation in weather conditions. A cheaper and more stable supply is therefore desirable. Here we present the first proof-of-concept of heterologous microbial production of carminic acid in Aspergillus nidulans by developing a semi-natural biosynthetic pathway. Formation of the tricyclic core of carminic acid is achieved via a two-step process wherein a plant type III polyketide synthase (PKS) forms a non-reduced linear octaketide, which subsequently is folded into the desired flavokermesic acid anthrone (FKA) structure by a cyclase and a aromatase from a bacterial type II PKS system. The formed FKA is oxidized to flavokermesic acid and kermesic acid, catalyzed by endogenous A. nidulans monooxygenases, and further converted to dcII and carminic acid by the Dactylopius coccus C-glucosyltransferase DcUGT2. The establishment of a functional biosynthetic carminic acid pathway in A. nidulans serves as an important step towards industrial-scale production of carminic acid via liquid-state fermentation using a microbial cell factory. PMID: 30150747 [PubMed - indexed for MEDLINE]

The induction of the fibroblast extracellular senescence metabolome is a dynamic process.

Tue, 29/10/2019 - 18:12
Related Articles The induction of the fibroblast extracellular senescence metabolome is a dynamic process. Sci Rep. 2018 08 14;8(1):12148 Authors: James ENL, Bennett MH, Parkinson EK Abstract Cellular senescence is often associated with irreparable DNA double strand breaks (IrrDSBs) which accumulate with chronological age (IrrDSBsen). The removal of senescent cells ameliorates several age-related diseases in mice but the translation of these findings into a clinical setting would be aided by the characterisation of non-invasive biomarkers of senescent cells. Several serum metabolites are independent indicators of chronological age and some of these accumulate outside senescent fibroblasts independently of cell cycle arrest, repairable DNA breaks and cell size (the extracellular senescence metabolome, or ESM). The post-mitotic phase of senescence is dynamic, making the detection of senescent cells in vivo difficult. An unbiased metabolomic screen of the IrrDSBsen fibroblast ESM also showed differences in the times of initiation and maintenance of different metabolites but generally the ESM altered progressively over the 20 day study period unlike the reported transcriptional profiles. This more detailed analysis of IrrDSBsen identified several new ESM metabolites that are associated with chronological ageing. Targeted analysis of citrate confirmed the dynamic nature of this metabolite in two cell lines and revealed its independence from the senescence effector p16INK4A. These data will aid our understanding of metabolic signatures of ageing and their relationship to cellular senescence and IrrDSBs. PMID: 30108296 [PubMed - indexed for MEDLINE]

Plasma metabolomic analysis in mature female common bottlenose dolphins: profiling the characteristics of metabolites after overnight fasting by comparison with data in beagle dogs.

Tue, 29/10/2019 - 18:12
Related Articles Plasma metabolomic analysis in mature female common bottlenose dolphins: profiling the characteristics of metabolites after overnight fasting by comparison with data in beagle dogs. Sci Rep. 2018 08 13;8(1):12030 Authors: Suzuki M, Yoshioka M, Ohno Y, Akune Y Abstract The present study was aimed at determining the characteristics of plasma metabolites in bottlenose dolphins to provide a greater understanding of their metabolism and to obtain information for the health management of cetaceans. Capillary electrophoresis-time-of-flight mass spectrometry (CE-TOFMS) and liquid chromatograph-time-of-flight mass spectrometry (LC-TOFMS) were conducted on plasma samples after overnight fasting from three common bottlenose dolphins as well as three beagle dogs (representative terrestrial carnivores) for comparison. In total, 257 and 227 plasma metabolites were identified in the dolphins and the dogs, respectively. Although a small number of animals were used for each species, the heatmap patterns, a principal component analysis and a cluster analysis confirmed that the composition of metabolites could be segregated from each other. Of 257 compounds detected in dolphin plasma, 24 compounds including branched amino acids, creatinine, urea, and methylhistidine were more abundant than in dogs; 26 compounds including long-chained acyl-carnitines and fatty acids, astaxanthin, and pantothenic acid were detected only in dolphins. In contrast, 25 compounds containing lactic acid and glycerol 3-phosphate were lower in dolphins compared to dogs. These data imply active protein metabolism, differences in usage of lipids, a unique urea cycle, and a low activity of the glycolytic pathway in dolphins. PMID: 30104643 [PubMed - indexed for MEDLINE]

Effect of storage conditions on salivary polyamines quantified via liquid chromatography-mass spectrometry.

Tue, 29/10/2019 - 18:12
Related Articles Effect of storage conditions on salivary polyamines quantified via liquid chromatography-mass spectrometry. Sci Rep. 2018 08 13;8(1):12075 Authors: Tomita A, Mori M, Hiwatari K, Yamaguchi E, Itoi T, Sunamura M, Soga T, Tomita M, Sugimoto M Abstract Salivary polyamines are potential non-invasive tools for screening various types of cancers. For clinical use, the reproducibility of these metabolites should be evaluated under various storage conditions, including duration and temperature, to establish standard operating protocols. Polyamines and amino acids in unstimulated whole saliva were quantified via liquid chromatography-mass spectrometry. Concentrations of time course samples were analysed after short-term storage for up to 240 min and long-term storage for up to 8 days under various storage conditions. As expected, storage at the lowest temperature (-18 °C) exerted the least pronounced effects on the quantified values in both tests. At a higher temperature, polyamines were more stable than amino acids, as evident from polyamine profiling. Addition of ethanol significantly stabilized polyamine profiles even at a higher temperature. Comparative processing of saliva revealed a minor effect of the solvent, whereas drying had a more prominent effect on polyamine profiles. Computational analyses evaluated the ability of polyamines to discriminate pancreatic cancer from controls. Repeated noise added tests were designed on the basis of the results of the storage tests; these analyses confirmed that the discriminative abilities were robust. These data contribute to the standardization of salivary storage conditions, thereby highlighting the clinical utility of saliva. PMID: 30104641 [PubMed - indexed for MEDLINE]

Metabolomic Profiles Reveal Potential Factors that Correlate with Lactation Performance in Sow Milk.

Tue, 29/10/2019 - 18:12
Related Articles Metabolomic Profiles Reveal Potential Factors that Correlate with Lactation Performance in Sow Milk. Sci Rep. 2018 Jul 16;8(1):10712 Authors: Tan C, Zhai Z, Ni X, Wang H, Ji Y, Tang T, Ren W, Long H, Deng B, Deng J, Yin Y Abstract Sow milk contains necessary nutrients for piglets; however, the relationship between the levels of metabolites in sow milk and lactation performance has not been thoroughly elucidated to date. In this study, we analysed the metabolites in sow milk from Yorkshire sows with high lactation (HL) or low lactation (LL) performance; these categories were assigned based on the weight gain of piglets during the entire lactation period (D1 to D21). The concentration of milk fat in the colostrum tended to be higher in the HL group (P = 0.05), the level of mannitol was significantly lower in the HL group (P < 0.05) and the level of glucuronic acid lactone was significantly higher in the HL group (P < 0.05) compared to those in LL group. In mature milk, the levels of lactose, creatine, glutamine, glutamate, 4-hydroxyproline, alanine, asparagine, and glycine were significantly higher (P < 0.05) in the HL group than those in LL group. The level of fatty acids showed no significant difference between the two groups in both the colostrum and mature milk. This study suggested that lactation performance may be associated with the levels of lactose and several amino acids in sow milk, and these results can be used to develop new feed additives to improve lactation performance in sows. PMID: 30013051 [PubMed - indexed for MEDLINE]

A multi-omic analysis reveals the role of fumarate in regulating the virulence of enterohemorrhagic Escherichia coli.

Tue, 29/10/2019 - 18:12
Related Articles A multi-omic analysis reveals the role of fumarate in regulating the virulence of enterohemorrhagic Escherichia coli. Cell Death Dis. 2018 03 07;9(3):381 Authors: Kuo CJ, Wang ST, Lin CM, Chiu HC, Huang CR, Lee DY, Chang GD, Chou TC, Chen JW, Chen CS Abstract The enteric pathogen enterohemorrhagic Escherichia coli (EHEC) is responsible for outbreaks of bloody diarrhea and hemolytic uremic syndrome (HUS) worldwide. Several molecular mechanisms have been described for the pathogenicity of EHEC; however, the role of bacterial metabolism in the virulence of EHEC during infection in vivo remains unclear. Here we show that aerobic metabolism plays an important role in the regulation of EHEC virulence in Caenorhabditis elegans. Our functional genomic analyses showed that disruption of the genes encoding the succinate dehydrogenase complex (Sdh) of EHEC, including the sdhA gene, attenuated its toxicity toward C. elegans animals. Sdh converts succinate to fumarate and links the tricarboxylic acid (TCA) cycle and the electron transport chain (ETC) simultaneously. Succinate accumulation and fumarate depletion in the EHEC sdhA mutant cells were also demonstrated to be concomitant by metabolomic analyses. Moreover, fumarate replenishment to the sdhA mutant significantly increased its virulence toward C. elegans. These results suggest that the TCA cycle, ETC, and alteration in metabolome all account for the attenuated toxicity of the sdhA mutant, and Sdh catabolite fumarate in particular plays a critical role in the regulation of EHEC virulence. In addition, we identified the tryptophanase (TnaA) as a downstream virulence determinant of SdhA using a label-free proteomic method. We demonstrated that expression of tnaA is regulated by fumarate in EHEC. Taken together, our multi-omic analyses demonstrate that sdhA is required for the virulence of EHEC, and aerobic metabolism plays important roles in the pathogenicity of EHEC infection in C. elegans. Moreover, our study highlights the potential targeting of SdhA, if druggable, as alternative preventive or therapeutic strategies by which to combat EHEC infection. PMID: 29515100 [PubMed - indexed for MEDLINE]

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