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Molecular and Population Level Approaches to Understand Taxus Metabolism in Cell Suspension CulturesPatil, Rohan Anil 01 February 2013 (has links)
Plant cell culture is an attractive platform technology for production and supply of important plant derived medicinals. A unique characteristic of plant cells is the ability to grow as multicellular aggregates in suspension. The presence of these non-uniform aggregates results in creation of distinct microenvironments, which can induce variations in cellular metabolism (e.g., growth, oxygen consumption and secondary metabolite synthesis). This heterogeneity can lead to unpredictable and suboptimal performance in large scale bioprocesses. One example is the Taxus cell culture system, which produces a widely used chemotherapeutic drug - paclitaxel (Taxol ®). Despite extensive process engineering efforts which have led to increased yields of paclitaxel, Taxus cells exhibit variability in productivity that is poorly understood. Elicitation of Taxus cultures with methyl jasmonate (MeJA) induces the accumulation of paclitaxel, but to varying extents in culture. A significant negative correlation was observed between paclitaxel level and mean aggregate size of the culture, demonstrating the relevance of measuring, and potentially controlling aggregate size during long term subculture.
Understanding the regulation of gene expression can provide rational engineering strategies to control variability and optimize performance of Taxus cell cultures. Biosynthetic pathway gene analyses revealed upregulation of genes upon elicitation with MeJA; results also suggested additional molecular regulatory points outside of the biosynthetic pathway. In order to fully understand Taxus molecular regulation and the relationship to paclitaxel production variability, a transcriptome-wide analysis using next generation sequencing (454 and Illumina) methods was performed. Several pathways outside of paclitaxel biosynthesis were found active upon MeJA elicitation. Global comparison of gene expression amongst cultures accumulating different levels of paclitaxel is being performed to completely understand the interactions amongst the paclitaxel biosynthetic pathway and other complimentary and competing pathways to suggest effective targets for metabolic engineering. This work collectively represents the first molecular studies to understand metabolic regulation in Taxus cell cultures.
Apart from inducing paclitaxel biosynthesis, MeJA decreases cell growth in Taxus cell cultures. The MeJA-mediated repression of cell growth was shown to correlate with inhibition of cell cycle progression as evident both at the culture level through flow cytometric analyses and at the transcriptional level by repression of key cell cycle-associated genes. Results from this study provide valuable insight into the mechanisms governing MeJA perception and subsequent events leading to repression of Taxus cell growth.
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Identification and evaluation of mycotoxins produced by Macrophomina phaseolinaKhambhati, Vivek Hemant 06 August 2021 (has links)
The fungus Macrophomina phaseolina (Tassi) Goidanich (Mp) is the causal agent of charcoal rot in soybean and infects over 500 plant species worldwide. Mp produces various mycotoxins and is suspected of utilizing a toxin-mediated process to penetrate host tissue. Identification and evaluation of secondary metabolites produced by Mp will further elucidate the pathogenesis mechanisms used by the fungus. Mp cultures isolated from soybean were evaluated for phytotoxicity in a hydroponic soybean bioassay and chemically analyzed by LC-MS/MS. All Mp cultures at two dilutions induced phytotoxicity symptoms including chlorosis, necrosis, wilting, stunting, and death. Analysis identified 13 unreported secondary metabolites including mellein, a compound with various biological activities. The phytotoxicity of mellein was evaluated against soybean seedlings in hydroponic culture, and symptoms of wilting and stunting were observed at levels above 40 MUg/L. Observations suggest that mellein does not directly contribute to the phytotoxic effects of Mp cultures.
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Metabolic Studies of Albomycin BiosynthesisKulkarni, Aditya S. January 2015 (has links)
No description available.
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Functional evolution of R2R3 MYB transcription factors in the grassesDias, Anusha P. 03 February 2004 (has links)
No description available.
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Use of Fish Biomarkers to Assess the Contaminant Exposure and Effects in Lake Erie TributariesYang, Xuan January 2004 (has links)
No description available.
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PHARMACOKINETICS OF RESVERATROL, ITS MONOCONJUGATES AND ITS TRIMETHOXY ANALOG TMSSharan, Satish January 2013 (has links)
Resveratrol (RES) has been associated with numerous pharmacological effects. Yet its pharmacokinetics is not clearly understood. It is known to get extensively metabolized into its sulfated and glucuronidated metabolites and has very low circulating RES concentrations in plasma. Although the concentrations of conjugated metabolites of RES have been reported to be much greater than that of RES, they have not been evaluated. This also becomes important in light of positive biological activities reported for sulfated metabolites of RES. Conjugation is a complex process which can sometimes be a reversible process and needs comprehensive evaluation to better understand RES and its metabolites' disposition. There has been a debate among the researchers regarding the differences in kinetics of preformed versus in vivo formed metabolites in the light of guidelines issued by regulatory bodies regarding metabolites in safety testing (MIST). We have addressed the above questions in this work, in addition to evaluating brain permeability of a potent RES analog, trimethoxy-trans-stilbene (TMS). Chapter 1 presents a detailed introduction, hypothesis and significance of my work. Chapter 2 includes the development and validation of a bioanalytical method for quantitation of RES and its metabolites on LC/MS/MS. We were able to develop and validate a robust bioanalytical method to quantitate RES and its four major metabolites resveratrol-4'-glucuronide (R4'G), resveratrol-3-glucuronide (R3G), resveratrol-4'-sulfate (R4'S) and resveratrol-3-sulfate (R3S). In Chapter 3, lung as a possible metabolizing organ for RES was evaluated. This study was performed in vivo in mouse model using multiple site of administration and single site of sampling approach. In vitro studies were also performed to confirm the in vivo results. Inter species differences in RES pulmonary metabolism were also studied. We observed lungs to be the major metabolizing organs for RES with inter species differences in its metabolism. Chapter 4 provides detailed pharmacokinetics of sulfated metabolites of RES, i.e. resveratrol-3-sulfate (R3S) and resveratrol-4'-sulfate (R4'S) in mouse model by both systemic and oral routes. In vitro studies were also conducted to test the desulfation in liver. Although we did not observe any significant RES in plasma, we observed from our in vitro studies that sulfated metabolites were desulfated in liver. Chapter 5 explains the detailed pharmacokinetics of glucuronidated metabolites of RES i.e. resveratrol-3-glucuornide (R3G) after both systemic and oral route. R3G was observed to undergo enterohepatic circulation. Explanation of R3G disposition in hepatocytes and enterocytes were proposed based on our own and reported results. In Chapter 6 we compared the differences in the kinetics of preformed versus in vivo formed metabolites using modeling and simulation approach. Individual models for disposition of RES, R3S and R3G were developed. These models were combined to give a global model for RES metabolism into R3S and R3G. Simulations were performed under two assumptions; preformed versus in vivo formed metabolite kinetics a) are same and b) they are not same. Our results reported that preformed and in vivo formed metabolite kinetics are not same at least for hydrophilic phase II metabolites. Chapter 7 includes method development and validation for quantitation of TMS in plasma and brain of mouse. Chapter 8 includes a steady state study to characterize the pharmacokinetic parameters of TMS, which was used to evaluate brain permeability of TMS. In summary we developed a robust bioanalytical method for direct quantitation of RES and its metabolites, found the lung to be a major metabolizing organ for RES, delineated complex kinetics of conjugated metabolites of RES, and showed differences in preformed versus in vivo formed metabolite kinetics and better brain permeability of TMS. / Pharmaceutical Sciences
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Improvement of Gastroparesis Management By Addressing Challenges in Drug Metabolism: Studies with Metabolite Identification, Reaction Phenotyping and In Vitro Drug-Drug InteractionsYoussef, Amir Samaan Bishara January 2013 (has links)
Gastroparesis is a disorder characterized by delayed gastric emptying due to chronic abnormal gastric motility. Prokinetic agents such as domperidone and metoclopramide are the cornerstone in treatment of gastroparesis. Although these medications have been used for decades, essential information about their metabolism is not available. Lack of knowledge about the metabolites formed in the body upon administration of the aforementioned medications as well as the enzymes involved in their metabolism limits key information needed to make sound medical decisions. Accurate and comprehensive identification of the metabolites along with reaction phenotyping of prokinetic agents will ensure safe and effective use of these drugs and hence enhance the clinical outcome. The thesis starts with an introductory chapter which comprises a comprehensive literature review on gastroparesis and the available pharmacological treatment options. The chapter also emphasizes the importance of metabolic profiling of prokinetic agents (domperidone and metoclopramide) and its impact on enhancing the safety and efficacy of these medications. Chapter 2 of this project was aimed to determine phase oxidative and conjugative metabolites of domperidone in the plasma and urine of gastroparesis patients using tandem mass spectrometry. First, the metabolites were identified in in-vitro human subcellular fractions. The knowledge gained in this experiment helped identifying the metabolites in the biological fluids of patients. In total, 12 metabolites including 7 new metabolites were identified, 5 of which were not reported previously. Chapter 3 aimed to identify the cytochrome P450 (CYP) enzymes responsible for the metabolism of metoclopramide. The parent depletion approach was used and a novel LC-MS/MS method was developed and validated to enable metoclopramide quantification. CYP2D6 was showed to the predominant isoform in metoclopramide metabolism; other isoforms also contribute to a minor extent. Chapter 4 discusses the possibility of potential drug-drug interaction (DDI) in the current management practice of gastroparesis. We identified and investigated some frequently used drug combinations that are known to share common metabolic pathways. Domperidone in combination with pioglitazone and ondansetron was evaluated. Results showed that pioglitazone inhibited domperidone metabolism in-vitro. Our experiments did not predict a DDI for the domperidone - ondansetron combination. In summary, the ultimate goal of this thesis was to improve the management of gastroparesis by increasing information about the metabolic disposition of prokinetic agents and to investigate the magnitude of putative drug combinations. The knowledge provided by this work will help in making more effective and less hazardous clinical decisions which will ultimately lead to more successful gastroparesis management. / Pharmaceutical Sciences
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Functional Analysis of Secondary Metabolite Biosynthesis-Related Genes in Alternaria brassicicolaKim, Kwang Hyung 07 October 2009 (has links)
Alternaria brassicicola is a necrotrophic pathogen that causes black spot disease on virtually all cultivated Brassicas, A. brassicicola is renowned for its ability to prodigiously produce secondary metabolites. To test the hypothesis that secondary metabolites produced by A. brassicicola contribute to pathogenicity, we identified seven nonribosomal peptide synthetases (NPSs) and 10 polyketide synthases (PKSs) in the A. brassicicola genome. The phenotype resulting from knockout mutations of each PKS and NPS gene was investigated with an emphasis on discovery of fungal virulence factors. A highly efficient gene disruption method using a short linear double stranded DNA construct with minimal elements was developed, optimized, and used to functionally disrupt all NPS and PKS genes in A. brassicicola. Three NPS and two PKS genes, and one NPS-like gene appeared to be virulence factors based upon reduced lesion development of each mutant on inoculated green cabbage and Arabidopsis compared with the wild-type strain. Furthermore some of the KO mutants exhibited developmental phenotypic changes in pigmentation and conidiogenesis. To further characterize the roles of several genes of interest in A. brassicicola development and pathogenesis, the genes AbNPS2, AbPKS9, and NPS-like tmpL were selected for in-depth functional analysis. We provide substantial evidence that the AbNPS2-associated metabolite is involved in conidial cell wall construction, possibly as an anchor connecting two cell wall layers. We also characterized a biosynthetic gene cluster harboring the AbPKS9 gene and demonstrated that this cluster is responsible for the biosynthesis of depudecin, an inhibitor of histone deacetylases and a minor virulence factor. Finally, we demonstrated that a NPS-like protein named TmpL is involved in a filamentous fungi-specific mechanism for regulating levels of intracellular reactive oxygen species during conidiation and pathogenesis in both plant and animal pathogenic fungi. Collectively our results indicate that small molecule nonribosomal peptides and polyketides in A. brassicicola play diverse, but also fundamental, roles in fungal development and pathogenesis. / Ph. D.
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Metabolic engineering of plants using a disarmed potyvirus vectorMajer, Eszter 01 September 2016 (has links)
Tesis por compendio / [EN] Plant viruses are obligate intracellular parasites which were used to develop recombinant plant virus vectors to express heterologous proteins and to modify endogenous metabolic pathways of natural products in plants. The main limitation of many plant virus-based systems is the difficulty to co-express various heterologous proteins in the same cell with proper subcellular localization, which is a crucial question in metabolic engineering. This work provides a solution to overcome this problem by using a potyvirus-based vector system. Potyviruses (genus Potyvirus, family Potyviridae) are plus-strand single-stranded RNA viruses, which have a genome expression strategy that allows the equimolar production of most viral proteins. On the basis of an infectious clone of Tobacco etch virus (TEV), Bedoya et al. (2010) developed an expression system in which the RNA-dependent RNA polymerase (NIb) gene was replaced by an expression cassette, harboring several heterologous proteins. This viral vector was able to express three fluorescent proteins with nucleocytoplasmic localization in equimolar amounts in transgenic tobacco plants in which NIb was supplemented in trans. Despite of the apparent simplicity of potyvirus genome expression strategy, foreign cDNA insertion is a complicated task. Thus, our first goal was to analyze the effect of gene insertion on TEV genome stability. As a result of this work, a novel insertion position was discovered at the amino-terminal end of the potyvirus polyprotein, which opened the possibility to explore new questions of recombinant protein expression. Since metabolic pathways are highly compartmentalized, proper subcellular targeting of enzymes is an essential task. Thus, our second objective centralized on the subcellular targeting of expressed proteins from the TEV-based viral vector. cDNAs coding for the green fluorescent protein (GFP) fused to chloroplast, nucleus and mitochondria targeting signal sequences were inserted into the newly described amino-terminal insertion position or into an internal site, replacing the NIb cistron. Our results showed that for protein delivery to chloroplasts and mitochondria, foreign genes have to be inserted at the amino-terminal site of the viral vector, but for nuclear delivery, both insertion positions are suitable. The last objective of this work was to investigate whether the potyvirus-based vector was able to express an entire heterologous multistep biosynthetic pathway in plant cells. For this aim we purposed to produce lycopene, a plant pigment with health promoting properties. To do so, we inserted cDNAs coding for the enzymes of a three-step metabolic pathway of bacterial origin into the potyvirus-based vector. Infected tobacco plants developed orange symptoms indicating lycopene accumulation, which was confirmed by high-performance liquid chromatography analysis and microscopy observations. Our results also illustrated that the sole expression of Pantoea ananatis phytoene synthase, crtB, is enough to induce carotenoid accumulation, conferring yellow coloration to the infected tissue and serves as reporter system to visually track viral infection in several plant species. / [ES] Los virus de plantas son parásitos intracelulares obligados que han sido utilizados para desarrollar vectores virales y expresar proteínas heterólogas y modificar rutas metabólicas endógenas de productos naturales. La principal limitación de muchos sistemas basados en virus de plantas es la dificultad de coexpresar diversas proteínas heterólogas en la misma célula con la localización subcelular apropiada, lo cual es una cuestión crucial en ingeniería metabólica. Este trabajo presenta una solución para superar este problema mediante el uso de un vector viral basado en un potyvirus. Los potyvirus (género Potyvirus, familia Potyviridae) son virus de RNA de cadena positiva simple que tienen una estrategia de expresión génica que permite la producción de la mayoría de las proteínas virales en cantidades equimolares. Basado en un clon infeccioso del virus del grabado del tabaco (Tobacco etch virus, TEV) Bedoya et al. (2010) desarrollaron un sistema de expresión en el que el gen de la RNA polimerasa dependiente de RNA (NIb) fue sustituido por un casete de expresión, que albergaba varias proteínas heterólogas. Este vector viral fue capaz de expresar tres proteínas fluorescentes con localización nucleocitoplásmica en cantidades equimolares en plantas de tabaco transgénicas que complementaban el cistron NIb en trans. A pesar de la aparente simplicidad de la estrategia de expresión génica de los potyvirus, la inserción de un cDNA foráneo es una tarea complicada. Por lo tanto, nuestro primer objetivo fue analizar el efecto de la inserción en la estabilidad del genoma de TEV. Como resultado de este trabajo, descubrimos una nueva posición de inserción en el extremo amino-terminal de la poliproteína viral que nos permitió explorar otras cuestiones sobre la expresión de proteínas recombinantes. Dado que las vías metabólicas son muy compartimentalizadas, la adecuada localización subcelular de enzimas es una tarea esencial en ingeniería metabólica. Por eso, nuestro segundo objetivo se centró en la distribución de las proteínas heterológas expresadas con el vector viral a diferentes orgánulos subcelulares. cDNAs que codificaban la proteína fluorescente verde (green fluorescent protein, GFP) fusionada a péptidos señal se insertaron en la nueva posición amino-terminal y en un sitio interno, sustituyendo el cistrón NIb, para enviarla al cloroplasto, núcleo y a la mitocondria. Nuestros resultados mostraron que para la distribución de proteínas al cloroplasto y mitocondria, los genes foráneos deben ser insertados en el sitio amino-terminal del vector viral, pero para la distribución nuclear, ambas posiciones son adecuadas. El último objetivo de este trabajo fue estudiar si el vector viral basado en potyvirus es capaz de expresar una ruta biosíntética de múltiples pasos en células vegetales. Para ello nos propusimos producir licopeno, un pigmento vegetal con propiedades beneficiosas para la salud humana. Para ello, insertamos un cDNA que codificaba las enzimas de una ruta metabólica de tres pasos de origen bacteriano en el vector viral. Las plantas de tabaco infectadas con el vector viral desarrollaron síntomas de color naranja indicando la acumulación de licopeno, que fue confirmado por análisis de cromatografía líquida de alta eficacia y observaciones de microscopía. Nuestros resultados también ilustraron que la sola expresión de la fitoeno sintasa de Pantonea ananatis, crtB, es suficiente para inducir la acumulación de carotenoides que confieren una coloración amarilla al tejido infectado y sirve como sistema reportero visual en varias especies de plantas. / [CA] Els virus de plantes són paràsits intracel·lulars obligats que han estat utilitzats per a desenvolupar vectors virals i expressar proteïnes heteròlogues y modificar rutes metabòliques endògenes de productes naturals silenciant certs gens o expressant factors de transcripció i enzims metabòlics. La principal limitació de molts sistemes basats en virus de plantes és la dificultat de coexpressar diverses proteïnes heteròlogues en la mateixa cèl·lula amb la localització subcel·lular apropiada, cosa que és una qüestió crucial en enginyeria metabòlica. Aquest treball presenta una solució per a superar aquest problema mitjançant l'ús d'un vector viral basat en un potyvirus. Els potyvirus (gènere Potyvirus, família Potyviridae) són virus d'RNA de cadena positiva simple que tenen una estratègia d'expressió gènica que permet la producció de la majoria de les proteïnes virals en quantitats equimolars. Basat en un clon infecciós del virus del gravat del tabac (Tobacco etch virus, TEV) Bedoya et al. (2010) van desenvolupar un sistema d'expressió en el qual el gen de l'RNA polimerasa depenent d'RNA (NIb) va ser substituït per un casset d'expressió, que albergava diverses proteïnes heteròlogues. Aquest vector viral va ser capaç d'expressar tres proteïnes fluorescents amb localització nucleocitoplàsmica en quantitats equimolars en plantes de tabac transgèniques que complementaven el cistró NIb en trans. Malgrat l'aparent simplicitat de l'estratègia d'expressió gènica dels potyvirus, la inserció d'un cDNA forà és una tasca complicada. Per tant, el nostre primer objectiu va ser analitzar l'efecte de la inserció en l'estabilitat del genoma de TEV. Com a resultat d'aquest treball, hem descobert una nova posició d'inserció en l'extrem amino terminal de la poliproteïna viral que ens va permetre explorar altres qüestions sobre l'expressió de proteïnes recombinants. Atès que les vies metabòliques són molt compartimentalitzades, l'adequada localització subcel·lular d'enzims és una tasca essencial en enginyeria metabòlica. Per açò, el nostre segon objectiu es va centrar en la distribució de les proteïnes heteròlogues expressades amb el vector viral a diferents orgànuls subcelul·lars. cDNAs que codificaven la proteïna fluorescent verda (green fluorescent protein, GFP) fusionada a pèptids senyal es van inserir en la nova posició amino terminal i en un lloc intern, substituint el cistró NIb, per a enviar-la al cloroplast, nucli i al mitocondri. Els nostres resultats van mostrar que per a la distribució de proteïnes al cloroplast i mitocondri, els gens forans han de ser inserits en el lloc amino terminal del vector viral, però per a la distribució nuclear, ambdues posicions són adequades. El lloc amino terminal va resultar ser més adequat per a produir quantitats més grans de proteïnes recombinants, però el lloc d'inserció intern va demostrar ser més estable. Sobre la base d'aquests resultats, hem sigut capaços de distribuir dues proteïnes fluorescents diferents als cloroplasts i nuclis des d'un únic vector viral. L'últim objectiu d'aquest treball va ser estudiar si el vector viral basat en potyvirus és capaç d'expressar una ruta biosintètica de múltiples passos en cèl·lules vegetals. Per açò ens vam proposar produir licopè, un pigment vegetal amb propietats beneficioses per a la salut humana. Per això inserírem un cDNA que codificaba els tres enzims de una ruta metabòlica de tres passos d'origen bacterià en el vector viral. Les plantes de tabac infectades amb el vector viral van desenvolupar símptomes de color taronja indicant l'acumulació de licopè, que va ser confirmat per anàlisi de cromatografia líquida d'alta eficàcia i observacions de microscòpia. Els nostres resultats també van il·lustrar que la sola expressió de fitoè sintasa de Pantonea ananatis, crtB, és suficient per a induir l'acumulació de carotenoides que confereixen una colora / Majer, E. (2016). Metabolic engineering of plants using a disarmed potyvirus vector [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/68477 / Compendio
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Multi-platform metabolomics assays to study the responsiveness of the human plasma and lung lavage metabolome / Multi-plattform metabolomik för analys av förändringar hos det humana metabolomet i plasma och lungsköljvätskaKarimpour, Masoumeh January 2016 (has links)
Metabolomics as a field has been used to track changes and perturbations in the human body by investigating metabolite profiles indicating the change of metabolite levels over time and in response to different challenges. In this thesis work, the main focus was on applying multiplatform-metabolomics to study the human metabolome following exposure to perturbations, such as diet (in the form of a challenge meal) and exhaust emissions (air pollution exposure in a controlled setting). The cutting-edge analytical platforms used for this purpose were nuclear magnetic resonance (NMR), as well as gas chromatography (GC) and liquid chromatography (LC) coupled to mass spectrometry (MS). Each platform offered unique characterization features, allowing detection and identification of a specific range of metabolites. The use of multiplatform-metabolomics was found to enhance the metabolome coverage and to provide complementary findings that enabled a better understanding of the biochemical processes reflected by the metabolite profiles. Using non-targeted analysis, a wide range of unknown metabolites in plasma were identified during the postprandial stage after a well-defined challenge meal (in Paper I). In addition, a considerable number of metabolites were detected and identified in lung lavage fluid after biodiesel exhaust exposure compared to filtered air exposure (in Paper II). In parallel, using targeted analysis, both lung lavage and plasma fatty acid metabolites were detected and quantified in response to filtered air and biodiesel exhaust exposure (in Paper III and IV). Data processing of raw data followed by data analysis, using both univariate and multivariate methods, enabled changes occurring in metabolites levels to be screened and investigated. For the initial pilot postprandial study, the aim was to investigate the plasma metabolome response after a well-defined meal during the postprandial stage for two types of diet. It was found that independent of the background diet type, levels of metabolites returned to their baseline levels after three hours. This finding was taken into consideration for the biodiesel exhaust exposures studies, designed to limit the impact of dietary effects. Both targeted and non-targeted approaches resulted in important findings. For instance, different metabolite profiles were detected in bronchial wash (BW) compared to bronchoalveolar lavage (BAL) fluid with mainly NMR and LC-MS. Furthermore, biodiesel exhaust exposure resulted in different metabolite profiles as observed by GC-MS, especially in BAL. In addition, fatty acid metabolites in BW, BAL, and plasma were shown to be responsive to biodiesel exhaust exposure, as measured by a targeted LC-MS/MS protocol. In summary, the new analytical methods developed to investigate the responsiveness of the human plasma and lung lavage metabolome proved to be useful in an analytical perspective, and provided important biological findings. However, further studies are needed to validate these results. / Metabolomik har använts för att spåra förändringar och störningar i kroppens funktioner genom undersökning av metabolit-profiler. I detta avhandlingasarbete har huvudfokus varit på tillämpning av flera olika analytiska plattformar för metabolomikstudier av det mänskliga metabolomet efter exponering för olika kost och avgasutsläpp från biodieselbränsle. De sofistikerade analytiska plattformarna som användes för detta ändamål var kärnmagnetisk resonans (NMR), samt gaskromatografi (GC) och vätskekromatografi (LC) kopplat till masspektrometri (MS). Varje plattform erbjöd unika karakteriseringsmöjligheter med detektion och identifiering av specifika grupper av metaboliter. Användningen av multipattformmetabolomik förbättrade täckningen av metabolomet och genererade kompletterande resultat som möjliggjorde en bättre förståelse av de biokemiska processer som reflekteras av metabolitprofilerna. Med hjälp av breda analyser har ett stort antal okända metaboliter i plasma identifierats under den postprandial fasen efter en väldefinerad måltid (i Paper I). Dessutom har ett stort antal metaboliter påvisats och identifierats i lungsköljvätska efter exponering av biodieselavgaser jämfört med kontollexponering med filtrerad luft (i Paper II). Parallellt med dessa breda analyser har också riktade analyser genomförts av både lungsköljvätska och plasma. Därigenom har bioaktiva lipider detekterats och kvantifieras efter avgasexponering och resultaten har jämförts med filtrerad luft som kontrollexponering (Paper III och IV). Processning av rådata följt av dataanalys, med både univariata och multivariata metoder möjliggjorde screening och fördjupad undersökning av förändringen i metabolitnivåer. I den första pilotstudien av postprandiala nivåer var syftet att undersöka responsen i plasmametabolomet efter en väldefinierad måltid under den postprandiala fasen vid två olika typer av kost. Resultaten visade att oberoende av kosten, så återvände metabolitnivåerna till sina baslinjenivåer tre timmar efter måltiden. Detta togs i beaktande vid exponeringsstudierna för biodieselavgaser, som designades så att dietens inverkan minimerades. Både breda och riktade analyser resulterade i viktiga resultat. Exempelvis så detekterades olika metabolitprofiler i bronkiell sköljvätska (BW) jämfört med bronkoalveolär sköljvätska (BAL), speciellt med NMR och LC-MS. Dessutom resulterade avgasexponering i förändrade metabolitprofiler, observerade med GC-MS, särskilt i BAL. Dessutom uppvisade fettsyrametaboliter i BW, BAL och plasma förändrade halter efter avgasexponering, uppmätt genom en riktad LC-MS/MS-analys. Sammanfattningsvis så visade sig de nya metoderna som utvecklats för att undersöka förändringar i metabolithalterna i plasma och lungsköljvätska fungera väl ur ett analytiskt perspektiv och resulterade i viktiga biologiska fynd. Fördjupade studier behövs dock för att validera resultaten.
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