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

Corrigendum to "Non-invasive metabolomics for improved determination of embryonic sex markers in chemically defined culture medium" [J. Chromatogr. A 1474 (2016) 138-144].

Mon, 06/11/2017 - 13:11
Corrigendum to "Non-invasive metabolomics for improved determination of embryonic sex markers in chemically defined culture medium" [J. Chromatogr. A 1474 (2016) 138-144]. J Chromatogr A. 2017 Oct 25;: Authors: Gómez E, Muñoz M, Simó C, Ibáñez C, Carrocera S, Martín-González D, Cifuentes A PMID: 29102058 [PubMed - as supplied by publisher]

Lipidomics reveals accumulation of the oxidized cholesterol in erythrocytes of heart failure patients.

Sun, 05/11/2017 - 12:39
Lipidomics reveals accumulation of the oxidized cholesterol in erythrocytes of heart failure patients. Redox Biol. 2017 Oct 26;14:499-508 Authors: Tang HY, Wang CH, Ho HY, Wu PT, Hung CL, Huang CY, Wu PR, Yeh YH, Cheng ML Abstract Lipids play an important role in the pathogenesis of cardiovascular disease. Changes in lipids of erythrocytes are indicative of the outcome of pathophysiological processes. In the present study, we assessed whether the lipid profiles of erythrocytes from heart failure (HF) patients are informative of their disease risk. The lipidomes of erythrocytes from 10 control subjects and 29 patients at different HF stages were analyzed using liquid chromatography time-of-flight mass spectrometry. The lipid composition of erythrocytes obtained from HF patients was significantly different from that of normal controls. The levels of phosphatidylcholines (PCs), phosphatidylethanolamines (PEs), and sphingomyelins decreased in HF erythrocytes as compared with those of control subjects; however, the levels of lysoPCs, lysoPEs, and ceramides increased in HF erythrocytes. Notably, the oxidized cholesterol 7-ketocholesterol (7KCh) accumulated to higher level in HF erythrocytes than in plasma from the same patients. We further validated our findings with a cohort of 115 subjects of control subjects (n=28) and patients (n=87). Mechanistically, 7KCh promoted reactive oxygen species (ROS) formation in cardiomyocytes; and induced their death, probably through an ATF4-dependent pathway. Our findings suggest that erythrocytic 7KCh can be a risk factor for HF, and is probably implicated in its pathophysiology. PMID: 29101899 [PubMed - as supplied by publisher]

Tracking maize pollen development by the Leaf Collar Method.

Sun, 05/11/2017 - 12:39
Related Articles Tracking maize pollen development by the Leaf Collar Method. Plant Reprod. 2017 Nov 04;: Authors: Begcy K, Dresselhaus T Abstract KEY MESSAGE: An easy and highly reproducible nondestructive method named the Leaf Collar Method is described to identify and characterize the different stages of pollen development in maize. In plants, many cellular events such as meiosis, asymmetric cell division, cell cycle regulation, cell fate determination, nucleus movement, vacuole formation, chromatin condensation and epigenetic modifications take place during pollen development. In maize, pollen development occurs in tassels that are confined within the internal stalk of the plant. Hence, identification of the different pollen developmental stages as a tool to investigate above biological processes is impossible without dissecting the entire plant. Therefore, an efficient and reproducible method is necessary to isolate homogeneous cell populations at individual stages throughout pollen development without destroying the plant. Here, we describe a method to identify the various stages of pollen development in maize. Using the Leaf Collar Method in the maize inbreed line B73, we have determined the duration of each stage from pollen mother cells before meiosis to mature tricellular pollen. Anther and tassel size as well as percentage of pollen stages were correlated with vegetative stages, which are easily recognized. The identification of stage-specific genes indicates the reproducibility of the method. In summary, we present an easy and highly reproducible nondestructive method to identify and characterize the different stages of pollen development in maize. This method now opens the way for many subsequent physiological, morphological and molecular analyses to study, for instance, transcriptomics, metabolomics, DNA methylation and chromatin patterns during normal and stressful conditions throughout pollen development in one of the economically most important grass species. PMID: 29101473 [PubMed - as supplied by publisher]

Shifts in microbial communities in soil, rhizosphere and roots of two major crop systems under elevated CO2 and O3.

Sun, 05/11/2017 - 12:39
Related Articles Shifts in microbial communities in soil, rhizosphere and roots of two major crop systems under elevated CO2 and O3. Sci Rep. 2017 Nov 03;7(1):15019 Authors: Wang P, Marsh EL, Ainsworth EA, Leakey ADB, Sheflin AM, Schachtman DP Abstract Rising atmospheric concentrations of CO2 and O3 are key features of global environmental change. To investigate changes in the belowground bacterial community composition in response to elevated CO2 and O3 (eCO2 and eO3) the endosphere, rhizosphere and soil were sampled from soybeans under eCO2 and maize under eO3. The maize rhizosphere and endosphere α-diversity was higher than soybean, which may be due to a high relative abundance of Rhizobiales. Only the rhizosphere microbiome composition of the soybeans changed in response to eCO2, associated with an increased abundance of nitrogen fixing microbes. In maize, the microbiome composition was altered by the genotype and linked to differences in root exudate profiles. The eO3 treatment did not change the microbial communities in the rhizosphere, but altered the soil communities where hybrid maize was grown. In contrast to previous studies that focused exclusively on the soil, this study provides new insights into the effects of plant root exudates on the composition of the belowground microbiome in response to changing atmospheric conditions. Our results demonstrate that plant species and plant genotype were key factors driving the changes in the belowground bacterial community composition in agroecosystems that experience rising levels of atmospheric CO2 and O3. PMID: 29101364 [PubMed - in process]

Butyrate reduces appetite and activates brown adipose tissue via the gut-brain neural circuit.

Sun, 05/11/2017 - 12:39
Related Articles Butyrate reduces appetite and activates brown adipose tissue via the gut-brain neural circuit. Gut. 2017 Nov 03;: Authors: Li Z, Yi CX, Katiraei S, Kooijman S, Zhou E, Chung CK, Gao Y, van den Heuvel JK, Meijer OC, Berbée JFP, Heijink M, Giera M, Willems van Dijk K, Groen AK, Rensen PCN, Wang Y Abstract OBJECTIVE: Butyrate exerts metabolic benefits in mice and humans, the underlying mechanisms being still unclear. We aimed to investigate the effect of butyrate on appetite and energy expenditure, and to what extent these two components contribute to the beneficial metabolic effects of butyrate. DESIGN: Acute effects of butyrate on appetite and its method of action were investigated in mice following an intragastric gavage or intravenous injection of butyrate. To study the contribution of satiety to the metabolic benefits of butyrate, mice were fed a high-fat diet with butyrate, and an additional pair-fed group was included. Mechanistic involvement of the gut-brain neural circuit was investigated in vagotomised mice. RESULTS: Acute oral, but not intravenous, butyrate administration decreased food intake, suppressed the activity of orexigenic neurons that express neuropeptide Y in the hypothalamus, and decreased neuronal activity within the nucleus tractus solitarius and dorsal vagal complex in the brainstem. Chronic butyrate supplementation prevented diet-induced obesity, hyperinsulinaemia, hypertriglyceridaemia and hepatic steatosis, largely attributed to a reduction in food intake. Butyrate also modestly promoted fat oxidation and activated brown adipose tissue (BAT), evident from increased utilisation of plasma triglyceride-derived fatty acids. This effect was not due to the reduced food intake, but explained by an increased sympathetic outflow to BAT. Subdiaphragmatic vagotomy abolished the effects of butyrate on food intake as well as the stimulation of metabolic activity in BAT. CONCLUSION: Butyrate acts on the gut-brain neural circuit to improve energy metabolism via reducing energy intake and enhancing fat oxidation by activating BAT. PMID: 29101261 [PubMed - as supplied by publisher]

Protein-bound uremic toxins impaired mitochondrial dynamics and functions.

Sun, 05/11/2017 - 12:39
Related Articles Protein-bound uremic toxins impaired mitochondrial dynamics and functions. Oncotarget. 2017 Sep 29;8(44):77722-77733 Authors: Sun CY, Cheng ML, Pan HC, Lee JH, Lee CC Abstract Protein-bound uremic toxins, indoxyl sulfate and p-cresol sulfate, increase oxidative stress and adversely affect chronic kidney disease progression and cardiovascular complications. In this study, we examined whether mitochondria are the target of indoxyl sulfate and p-cresol sulfate intoxication in vivo and in vitro. The kidneys of 10-week-old male B-6 mice with ½-nephrectomy treated with indoxyl sulfate and p-cresol sulfate were used for the animal study. Cultured human renal tubular cells were used for the in vitro study. Our results indicated that indoxyl sulfate and p-cresol sulfate impaired aerobic and anaerobic metabolism in vivo and in vitro. Indoxyl sulfate and p-cresol sulfate caused mitochondrial fission by modulating the expression of mitochondrial fission-fusion proteins. Mitochondrial dysfunction and impaired biogenesis could be protected by treatment with antioxidants. The in vitro study also demonstrated that indoxyl sulfate and p-cresol sulfate reduced mitochondrial mass by activating autophagic machinery. In summary, our study suggests that mitochondrial injury is one of the major pathological mechanisms for uremic intoxication, which is related to chronic kidney disease and its complications. PMID: 29100420 [PubMed]

metabolomics; +24 new citations

Sat, 04/11/2017 - 15:19
24 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 2017/11/04PubMed 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; +24 new citations

Sat, 04/11/2017 - 12:16
24 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 2017/11/04PubMed 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 based predictive biomarker model of ARDS: A systemic measure of clinical hypoxemia.

Fri, 03/11/2017 - 11:54
Metabolomics based predictive biomarker model of ARDS: A systemic measure of clinical hypoxemia. PLoS One. 2017;12(11):e0187545 Authors: Sinha N, Viswan A, Singh C, Rai RK, Azim A, Baronia AK Abstract Despite advancements in ventilator technologies, lung supportive and rescue therapies, the outcome and prognostication in acute respiratory distress syndrome (ARDS) remains incremental and ambiguous. Metabolomics is a potential insightful measure to the diagnostic approaches practiced in critical disease settings. In our study patients diagnosed with mild and moderate/severe ARDS clinically governed by hypoxemic P/F ratio between 100-300 but with indistinct molecular phenotype were discriminated employing nuclear magnetic resonance (NMR) based metabolomics of mini bronchoalveolar lavage fluid (mBALF). Resulting biomarker prototype comprising six metabolites was substantiated highlighting ARDS susceptibility/recovery. Both the groups (mild and moderate/severe ARDS) showed distinct biochemical profile based on 83.3% classification by discriminant function analysis and cross validated accuracy of 91% using partial least squares discriminant analysis as major classifier. The predictive performance of narrowed down six metabolites were found analogous with chemometrics. The proposed biomarker model consisting of six metabolites proline, lysine/arginine, taurine, threonine and glutamate were found characteristic of ARDS sub-stages with aberrant metabolism observed mainly in arginine, proline metabolism, lysine synthesis and so forth correlating to diseased metabotype. Thus NMR based metabolomics has provided new insight into ARDS sub-stages and conclusively a precise biomarker model proposed, reflecting underlying metabolic dysfunction aiding prior clinical decision making. PMID: 29095932 [PubMed - in process]

"Omic" investigations of protozoa and worms for a deeper understanding of the human gut "parasitome".

Fri, 03/11/2017 - 11:54
"Omic" investigations of protozoa and worms for a deeper understanding of the human gut "parasitome". PLoS Negl Trop Dis. 2017 Nov;11(11):e0005916 Authors: Marzano V, Mancinelli L, Bracaglia G, Del Chierico F, Vernocchi P, Di Girolamo F, Garrone S, Tchidjou Kuekou H, D'Argenio P, Dallapiccola B, Urbani A, Putignani L Abstract The human gut has been continuously exposed to a broad spectrum of intestinal organisms, including viruses, bacteria, fungi, and parasites (protozoa and worms), over millions of years of coevolution, and plays a central role in human health. The modern lifestyles of Western countries, such as the adoption of highly hygienic habits, the extensive use of antimicrobial drugs, and increasing globalisation, have dramatically altered the composition of the gut milieu, especially in terms of its eukaryotic "citizens." In the past few decades, numerous studies have highlighted the composition and role of human intestinal bacteria in physiological and pathological conditions, while few investigations exist on gut parasites and particularly on their coexistence and interaction with the intestinal microbiota. Studies of the gut "parasitome" through "omic" technologies, such as (meta)genomics, transcriptomics, proteomics, and metabolomics, are herein reviewed to better understand their role in the relationships between intestinal parasites, host, and resident prokaryotes, whether pathogens or commensals. Systems biology-based profiles of the gut "parasitome" under physiological and severe disease conditions can indeed contribute to the control of infectious diseases and offer a new perspective of omics-assisted tropical medicine. PMID: 29095820 [PubMed - in process]

Mass spectrometry based metabolomics: a novel analytical technique for detecting metabolic syndrome?

Fri, 03/11/2017 - 11:54
Mass spectrometry based metabolomics: a novel analytical technique for detecting metabolic syndrome? Bioanalysis. 2017 Nov 02;: Authors: Sallese A, Zhu J PMID: 29095044 [PubMed - as supplied by publisher]

Metabolomics for the masses: The future of metabolomics in a personalized world.

Fri, 03/11/2017 - 11:54
Metabolomics for the masses: The future of metabolomics in a personalized world. New Horiz Transl Med. 2017 Mar;3(6):294-305 Authors: Trivedi DK, Hollywood KA, Goodacre R Abstract Current clinical practices focus on a small number of biochemical directly related to the pathophysiology with patients and thus only describe a very limited metabolome of a patient and fail to consider the interations of these small molecules. This lack of extended information may prevent clinicians from making the best possible therapeutic interventions in sufficient time to improve patient care. Various post-genomics '('omic)' approaches have been used for therapeutic interventions previously. Metabolomics now a well-established'omics approach, has been widely adopted as a novel approach for biomarker discovery and in tandem with genomics (especially SNPs and GWAS) has the potential for providing systemic understanding of the underlying causes of pathology. In this review, we discuss the relevance of metabolomics approaches in clinical sciences and its potential for biomarker discovery which may help guide clinical interventions. Although a powerful and potentially high throughput approach for biomarker discovery at the molecular level, true translation of metabolomics into clinics is an extremely slow process. Quicker adaptation of biomarkers discovered using metabolomics can be possible with novel portable and wearable technologies aided by clever data mining, as well as deep learning and artificial intelligence; we shall also discuss this with an eye to the future of precision medicine where metabolomics can be delivered to the masses. PMID: 29094062 [PubMed]

Metabolomics guided pathway analysis reveals link between cancer metastasis, cholesterol sulfate, and phospholipids.

Fri, 03/11/2017 - 11:54
Metabolomics guided pathway analysis reveals link between cancer metastasis, cholesterol sulfate, and phospholipids. Cancer Metab. 2017;5:9 Authors: Johnson CH, Santidrian AF, LeBoeuf SE, Kurczy ME, Rattray NJW, Rattray Z, Warth B, Ritland M, Hoang LT, Loriot C, Higa J, Hansen JE, Felding BH, Siuzdak G Abstract Background: Cancer cells that enter the metastatic cascade require traits that allow them to survive within the circulation and colonize distant organ sites. As disseminating cancer cells adapt to their changing microenvironments, they also modify their metabolism and metabolite production. Methods: A mouse xenograft model of spontaneous tumor metastasis was used to determine the metabolic rewiring that occurs between primary cancers and their metastases. An "autonomous" mass spectrometry-based untargeted metabolomic workflow with integrative metabolic pathway analysis revealed a number of differentially regulated metabolites in primary mammary fat pad (MFP) tumors compared to microdissected paired lung metastases. The study was further extended to analyze metabolites in paired normal tissues which determined the potential influence of metabolites from the microenvironment. Results: Metabolomic analysis revealed that multiple metabolites were increased in metastases, including cholesterol sulfate and phospholipids (phosphatidylglycerols and phosphatidylethanolamine). Metabolite analysis of normal lung tissue in the mouse model also revealed increased levels of these metabolites compared to tissues from normal MFP and primary MFP tumors, indicating potential extracellular uptake by cancer cells in lung metastases. These results indicate a potential functional importance of cholesterol sulfate and phospholipids in propagating metastasis. In addition, metabolites involved in DNA/RNA synthesis and the TCA cycle were decreased in lung metastases compared to primary MFP tumors. Conclusions: Using an integrated metabolomic workflow, this study identified a link between cholesterol sulfate and phospholipids, metabolic characteristics of the metastatic niche, and the capacity of tumor cells to colonize distant sites. PMID: 29093815 [PubMed]

Integrative field scale phenotyping for investigating metabolic components of water stress within a vineyard.

Fri, 03/11/2017 - 11:54
Integrative field scale phenotyping for investigating metabolic components of water stress within a vineyard. Plant Methods. 2017;13:90 Authors: Gago J, Fernie AR, Nikoloski Z, Tohge T, Martorell S, Escalona JM, Ribas-Carbó M, Flexas J, Medrano H Abstract Background: There is currently a high requirement for field phenotyping methodologies/technologies to determine quantitative traits related to crop yield and plant stress responses under field conditions. Methods: We employed an unmanned aerial vehicle equipped with a thermal camera as a high-throughput phenotyping platform to obtain canopy level data of the vines under three irrigation treatments. High-resolution imagery (< 2.5 cm/pixel) was employed to estimate the canopy conductance (gc ) via the leaf energy balance model. In parallel, physiological stress measurements at leaf and stem level as well as leaf sampling for primary and secondary metabolome analysis were performed. Results: Aerial gc correlated significantly with leaf stomatal conductance (gs ) and stem sap flow, benchmarking the quality of our remote sensing technique. Metabolome profiles were subsequently linked with gc and gs via partial least square modelling. By this approach malate and flavonols, which have previously been implicated to play a role in stomatal function under controlled greenhouse conditions within model species, were demonstrated to also be relevant in field conditions. Conclusions: We propose an integrative methodology combining metabolomics, organ-level physiology and UAV-based remote sensing of the whole canopy responses to water stress within a vineyard. Finally, we discuss the general utility of this integrative methodology for broad field phenotyping. PMID: 29093742 [PubMed]

Dynamic Labeling Reveals Temporal Changes in Carbon Re-Allocation within the Central Metabolism of Developing Apple Fruit.

Fri, 03/11/2017 - 11:54
Dynamic Labeling Reveals Temporal Changes in Carbon Re-Allocation within the Central Metabolism of Developing Apple Fruit. Front Plant Sci. 2017;8:1785 Authors: Beshir WF, Mbong VBM, Hertog MLATM, Geeraerd AH, Van den Ende W, Nicolaï BM Abstract In recent years, the application of isotopically labeled substrates has received extensive attention in plant physiology. Measuring the propagation of the label through metabolic networks may provide information on carbon allocation in sink fruit during fruit development. In this research, gas chromatography coupled to mass spectrometry based metabolite profiling was used to characterize the changing metabolic pool sizes in developing apple fruit at five growth stages (30, 58, 93, 121, and 149 days after full bloom) using (13)C-isotope feeding experiments on hypanthium tissue discs. Following the feeding of [U-(13)C]glucose, the (13)C-label was incorporated into the various metabolites to different degrees depending on incubation time, metabolic pathway activity, and growth stage. Evidence is presented that early in fruit development the utilization of the imported sugars was faster than in later developmental stages, likely to supply the energy and carbon skeletons required for cell division and fruit growth. The declined (13)C-incorporation into various metabolites during growth and maturation can be associated with the reduced metabolic activity, as mirrored by the respiratory rate. Moreover, the concentration of fructose and sucrose increased during fruit development, whereas concentrations of most amino and organic acids and polyphenols declined. In general, this study showed that the imported compounds play a central role not only in carbohydrate metabolism, but also in the biosynthesis of amino acid and related protein synthesis and secondary metabolites at the early stage of fruit development. PMID: 29093725 [PubMed]

Spatiotemporal analysis of tropical disease research combining Europe PMC and affiliation mapping web services.

Fri, 03/11/2017 - 11:54
Spatiotemporal analysis of tropical disease research combining Europe PMC and affiliation mapping web services. Trop Med Health. 2017;45:33 Authors: Palmblad M, Torvik VI Abstract Background: Tropical medicine appeared as a distinct sub-discipline in the late nineteenth century, during a period of rapid European colonial expansion in Africa and Asia. After a dramatic drop after World War II, research on tropical diseases have received more attention and research funding in the twenty-first century. Methods: We used Apache Taverna to integrate Europe PMC and MapAffil web services, containing the spatiotemporal analysis workflow from a list of PubMed queries to a list of publication years and author affiliations geoparsed to latitudes and longitudes. The results could then be visualized in the Quantum Geographic Information System (QGIS). Results: Our workflows automatically matched 253,277 affiliations to geographical coordinates for the first authors of 379,728 papers on tropical diseases in a single execution. The bibliometric analyses show how research output in tropical diseases follow major historical shifts in the twentieth century and renewed interest in and funding for tropical disease research in the twenty-first century. They show the effects of disease outbreaks, WHO eradication programs, vaccine developments, wars, refugee migrations, and peace treaties. Conclusions: Literature search and geoparsing web services can be combined in scientific workflows performing a complete spatiotemporal bibliometric analyses of research in tropical medicine. The workflows and datasets are freely available and can be used to reproduce or refine the analyses and test specific hypotheses or look into particular diseases or geographic regions. This work exceeds all previously published bibliometric analyses on tropical diseases in both scale and spatiotemporal range. PMID: 29093641 [PubMed]

Loss of miR-141/200c ameliorates hepatic steatosis and inflammation by reprogramming multiple signaling pathways in NASH.

Fri, 03/11/2017 - 11:54
Loss of miR-141/200c ameliorates hepatic steatosis and inflammation by reprogramming multiple signaling pathways in NASH. JCI Insight. 2017 Nov 02;2(21): Authors: Tran M, Lee SM, Shin DJ, Wang L Abstract Accumulation of lipid droplets and inflammatory cell infiltration is the hallmark of nonalcoholic steatohepatitis (NASH). The roles of noncoding RNAs in NASH are less known. We aim to elucidate the function of miR-141/200c in diet-induced NASH. WT and miR-141/200c-/- mice were fed a methionine and choline deficient (MCD) diet for 2 weeks to assess markers of steatosis, liver injury, and inflammation. Hepatic miR-141 and miR-200c RNA levels were highly induced in human patients with NASH fatty liver and in WT MCD mice. miR-141/200c-/- MCD mice had reduced liver weights and triglyceride (TG) levels, which was associated with increased microsomal TG transfer protein (MTTP) and PPARα but reduced SREBP1c and FAS expression. Inflammation was attenuated and F4/80 macrophage activation was suppressed in miR-141/200c-/- mice, as evidenced by decreased serum aminotransferases and IL-6 and reduced hepatic proinflammatory, neutrophil, and profibrotic genes. Treatment with LPS in BM-derived macrophages isolated from miR-200c/141-/- mice polarized macrophages toward the M2 antiinflammatory state by increasing Arg1 and IL-10 levels while decreasing the M1 marker iNOS. In addition, elevated phosphorylated AMPK (p-AMPK), p-AKT, and p-GSK3β and diminished TLR4 and p-mTOR/p-4EBP1 proteins were observed. Lipidomics and metabolomics revealed alterations of TG and phosphatidylcholine (PC) lipid species by miR-141/200c deficiency. In summary, miR-141/200c deficiency diminished NASH-associated hepatic steatosis and inflammation by reprogramming lipid and inflammation signaling pathways. PMID: 29093267 [PubMed - as supplied by publisher]

High intracellular c-di-GMP levels antagonize quorum sensing and virulence gene expression in Burkholderia cenocepacia H111.

Fri, 03/11/2017 - 11:54
Related Articles High intracellular c-di-GMP levels antagonize quorum sensing and virulence gene expression in Burkholderia cenocepacia H111. Microbiology. 2017 May;163(5):754-764 Authors: Schmid N, Suppiger A, Steiner E, Pessi G, Kaever V, Fazli M, Tolker-Nielsen T, Jenal U, Eberl L Abstract The opportunistic human pathogen Burkholderia cenocepacia H111 uses two chemically distinct signal molecules for controlling gene expression in a cell density-dependent manner: N-acyl-homoserine lactones (AHLs) and cis-2-dodecenoic acid (BDSF). Binding of BDSF to its cognate receptor RpfR lowers the intracellular c-di-GMP level, which in turn leads to differential expression of target genes. In this study we analysed the transcriptional profile of B. cenocepacia H111 upon artificially altering the cellular c-di-GMP level. One hundred and eleven genes were shown to be differentially expressed, 96 of which were downregulated at a high c-di-GMP concentration. Our analysis revealed that the BDSF, AHL and c-di-GMP regulons overlap for the regulation of 24 genes and that a high c-di-GMP level suppresses expression of AHL-regulated genes. Phenotypic analyses confirmed changes in the expression of virulence factors, the production of AHL signal molecules and the biosynthesis of different biofilm matrix components upon altered c-di-GMP levels. We also demonstrate that the intracellular c-di-GMP level determines the virulence of B. cenocepacia to Caenorhabditis elegans and Galleria mellonella. PMID: 28463102 [PubMed - indexed for MEDLINE]

Analysis of the Biotechnological Potential of a Lentinus crinitus Isolate in the Light of Its Secretome.

Fri, 03/11/2017 - 11:54
Related Articles Analysis of the Biotechnological Potential of a Lentinus crinitus Isolate in the Light of Its Secretome. J Proteome Res. 2016 Dec 02;15(12):4557-4568 Authors: Cambri G, de Sousa MM, Fonseca DM, Marchini F, da Silveira JL, Paba J Abstract Analysis of fungal secretomes is a prospection tool for the discovery of new catalysts with biotechnological applications. Since enzyme secretion is strongly modulated by environmental factors, evaluation of growth conditions is of utmost importance to achieve optimal enzyme production. In this work, a nonsequenced wood-rotting fungus, Lentinus crinitus, was used for secretome analysis by enzymatic assays and a proteomics approach. Enzyme production was assessed after the fungus was cultured in seven different carbon sources and three nitrogen-containing compounds. The biomass yields and secreted protein arrays differed drastically among growing conditions. A mixture of secreted extracts derived from solid and liquid cultures was inspected by shotgun mass spectrometry and two-dimensional gel electrophoresis (2-DE) prior to analysis via LC-MS/MS. Proteins were identified using mass spectrometry (MS)-driven BLAST. The spectrum of secreted proteins comprised CAZymes, oxidase/reductases, proteases, and lipase/esterases. Although preseparation by 2-DE improved the number of identifications (162) compared with the shotgun approach (98 identifications), the two strategies revealed similar protein patterns. Culture media with reduced water content stimulated the expression of oxidases/reductases, while hydrolases were induced during submerged fermentation. The diversity of proteins observed within both the CAZyme and oxidoreductase groups revealed in this fungus a powerful arsenal of enzymes dedicated to the breakdown and consumption of lignocellulose. PMID: 27796094 [PubMed - indexed for MEDLINE]

Biochemometrics to Identify Synergists and Additives from Botanical Medicines: A Case Study with Hydrastis canadensis (Goldenseal).

Thu, 02/11/2017 - 11:15
Biochemometrics to Identify Synergists and Additives from Botanical Medicines: A Case Study with Hydrastis canadensis (Goldenseal). J Nat Prod. 2017 Nov 01;: Authors: Britton ER, Kellogg JJ, Kvalheim OM, Cech NB Abstract A critical challenge in the study of botanical natural products is the difficulty of identifying multiple compounds that may contribute additively, synergistically, or antagonistically to biological activity. Herein, it is demonstrated how combining untargeted metabolomics with synergy-directed fractionation can be effective toward accomplishing this goal. To demonstrate this approach, an extract of the botanical goldenseal (Hydrastis canadensis) was fractionated and tested for its ability to enhance the antimicrobial activity of the alkaloid berberine (4) against the pathogenic bacterium Staphylococcus aureus. Bioassay data were combined with untargeted mass spectrometry-based metabolomics data sets (biochemometrics) to produce selectivity ratio (SR) plots, which visually show which extract components are most strongly associated with the biological effect. Using this approach, the new flavonoid 3,3'-dihydroxy-5,7,4'-trimethoxy-6,8-C-dimethylflavone (29) was identified, as were several flavonoids known to be active. When tested in combination with 4, 29 lowered the IC50 of 4 from 132.2 ± 1.1 μM to 91.5 ± 1.1 μM. In isolation, 29 did not demonstrate antimicrobial activity. The current study highlights the importance of fractionation when utilizing metabolomics for identifying bioactive components from botanical extracts and demonstrates the power of SR plots to help merge and interpret complex biological and chemical data sets. PMID: 29091439 [PubMed - as supplied by publisher]

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