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Role of antioxidant defense in the synthesis of antidiabetic lipokines
Domanská, Veronika ; Kuda, Ondřej (advisor) ; Zouhar, Petr (referee) ; Vrkoslav, Vladimír (referee)
Fatty acid esters of hydroxy fatty acids (FAHFAs) are a recently discovered group of lipokines consisting of a fatty acid attached to a hydroxy fatty acid with an ester bond resulting in a diverse group of compounds with many different biological activities. Antidiabetic and anti-inflammatory activities are the most studied. The thesis aimed to study this group of bioactive lipids to elucidate the metabolism of FAHFAs and describe the role of antioxidant defense, namely peroxiredoxin 6 (Prdx6), in their biosynthesis with the help of isotopic labeling together with in vitro and in vivo experiments. All the samples, including white adipose tissue, liver, and even human breast milk, were subjected to untargeted or targeted lipidomic and metabolomics analysis using LC-MS/MS. We used the data from isotopically labeled experiments to describe the role of 5-PAHSA in glucose uptake and to show which specific pathways are stimulated by 5-PAHSA administration and which by insulin to compare the effect of both antidiabetic agents. In our samples, we analyzed TAG estolides, which function as intracellular reservoirs of FAHFAs, and managed to describe the role of specific lipases in their metabolism. We reported the role of Prdx6 and the specific enzymatic activity involved in synthesizing precursors that could...
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Obesity its causes and cosequences
Ondráčková, Anna ; Vybíral, Stanislav (advisor) ; Kuda, Ondřej (referee)
Obesity is one of the most common health problems in the Word. Over 500 million adults and over 40 million children are obese. The aim of this work is to summarize findings of causes and consequences of this health problem. Even though in some cases only genetic mutations are responsible for obesity for example mutation in ob gene or Prader-Willi syndrome most cases are caused by lifestyle of people -excessive food intake and insufficient physical activity. There are many health problems accompanying obesity. The most serious problems are metabolic syndrome, diabetes mellitus, cardiovascular diseases and cancer. The consequences of obesity are, however, not confined only to health. We can also observe the economic consequences. Financial cost of treatment of obesity and related diseases are estimated in billions of dollars. Pharmacological treatment has so far proved to be ineffective. If drugs are effective, the side effects are so severe that their use is not possible. So far, the adipose tissue hormones that regulate food intake provide the best hope.
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Targeted analysis of eicosanoids by LC/MS
Moravcová, Marie ; Kuda, Ondřej (advisor) ; Kozlík, Petr (referee)
Eicosanoids represent large group of biologically active lipid metabolites syntesized from polyunsaturated fatty acids that play an important role in many physiological processes. To describe complex metabolism of these compounds, analytical methods including extraction from a biological sample using solid phase extraction and liquid chromatography coupled with mass spectrometer detection were used. Solid phase extraction of biological samples was optimized on four types of reverse phase columns of which column Strata X 60 mg/3 ml, 33 um (Phenomenex , USA) was the most effective. Also, alternative solid phase extraction of eicosanoids using columns with ion exchange sorbents and a column with normal phase were tested, but proved to be unsuitable for targeted analysis of eicosanoids. The extraction method yielding the best results - Strata X 60 mg/3 ml, 33 µm (Phenomenex, USA) was used for the separation of eicosanoids from mouse gonadal fat samples. Eicosanoids were analyzed by liquid chromatography and the separation mechanisms were tested on three UPLC core-shell columns of different lengths (50 mm, 100 mm, 150 mm). The most effective separation of prostaglandin E2 and prostaglandin D2 was achieved using the longest column Kinetex 150 mm × 2,1 mm, 2,6 µm. Furthermore, ionization parameters, such...
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Lipidomic analysis of vernix caseosa
Harazim, Eva ; Cvačka, Josef (advisor) ; Lísa, Miroslav (referee) ; Kuda, Ondřej (referee)
Methods of analytical chemistry are widely used in lipidomics. Separation techniques coupled to mass spectrometry or nuclear magnetic resonance are used very often. They make it possible to identify lipids present in the matrix in very small quantities. This work summarizes the application of modern analytical methods and instrumentation for identifying and characterizing lipids in vernix caseosa. It is shown how I contributed during the Ph.D. studies to the elucidation of the structure and characterization of unknown lipid classes followed by more detailed description of those lipid classes already identified in vernix caseosa. An integral part of my work was the application of the method enabling the localization of double bonds developed by our laboratory in triacylglycerols and 1,2-diol diesters in vernix caseosa. This analytical method is based on the formation of an acetonitrile adduct in an ionization source of a mass spectrometer enabling atmospheric pressure ionization. The complexity of the triacylglycerol class did not allow a complete characterization of the double bonds. However, the fragmentation mostly showed that double bonds up to n-12 position are present, but small peaks in some spectra also indicated double bonds at more distant positions from the chain termini. I have also...
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Role of phospholipases A2 in the mechanism of cardioprotection induced by adaptation to chronic hypoxia
Míčová, Petra ; Novotný, Jiří (advisor) ; Kuda, Ondřej (referee) ; Kazdová, Ludmila (referee)
Cardiovascular diseases, particularly acute myocardial infarction, are the leading causes of death in developed countries including the Czech Republic. One of the ways to increase cardiac resistance against acute ischemia/reperfusion (I/R) injury is adaptation to chronic hypoxia. However, changes at the molecular level associated with this adaptation have still not been fully explored. It is obvious that the myocardial function depends on maintaining membrane integrity and cellular homeostasis of cardiomyocytes. From this perspective, phospholipases A2 (PLA2) are the key enzymes that take part in the remodeling and repairing of the cell membranes. Moreover, PLA2 are also involved in generation of lipid signaling molecules - free long chain fatty acids (FA) and 2-lysophopholipids. In myocardium, members of three major PLA2 classes are present: cytosolic PLA2 (cPLA2), calcium-independent PLA2 (iPLA2) and secretoric PLA2 (sPLA2). This thesis aimed to determine the following in the left ventricular myocardium of adult male Wistar rats: 1) The effect of intermittent hypobaric hypoxia (IHH; 8 hours/day, 5 days/week, 5 weeks, ~ 7000 m) on the expression of total cPLA2α and its phosphorylated form (p-cPLA2α, Ser505 ), and further iPLA2 and sPLA2IIA, as well as signaling proteins activating cPLA2α enzyme...
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Metabolipidomic profiling of white adipose tissue by UPLC-MS/MS
Rombaldová, Martina ; Kuda, Ondřej (advisor) ; Šiklová, Michaela (referee) ; Čajka, Tomáš (referee)
Obesity is a serious problem in society today [1,2]. It might seems to have been caused simply by excess consumption of food compared to energy expenditure but obesity is actually a complex metabolic disorder centred on adipose lipid metabolism and cellular signalling systems linked to it [3]. Understanding the biology of adipose tissue (AT) is very important for the identification of novel and potential therapeutic targets in order to prevent and treat obesity-related disorders [4]. We utilized analytical approach liquid chromatography coupled to mass spectrometry (LC-MS) to study adipose tissue metabolism. Also, we were especially interested in the effect of omega-3 polyunsaturated fatty acids (PUFA) on that metabolism. Rodent and cell line experiments were performed and analyses were done of white adipose tissue (WAT), serum/plasma samples or cells as well as milk samples from mothers. At first, we established several ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) methods for analysis of acylcarnitines (AC), amino acids (AmA) and other metabolites. Importantly, these methods were able to distinguish isobaric species of AC which is not usually possible. Using these approaches we uncovered several acylcarnitines, i.e. long chain AC, carnitine, acylcarnitine C4 and...
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Targeted analysis and metabolism of fatty acids in mice and humans
Oseeva, Marina ; Kuda, Ondřej (advisor) ; Cahová, Monika (referee) ; Vrkoslav, Vladimír (referee)
Widespread sedentary lifestyle and unhealthy eating habits in the last few decades have resulted in a dramatic increase of the number of people affected by obesity, type 2 diabetes, and cardiovascular diseases. The study of these pathological conditions revealed that impaired metabolism often causes these disorders. Lipid metabolism research has contributed significantly to determining mechanisms underlying metabolic disorders. Omega-3 fatty acids are an interesting target for lipidomics studies because they were shown to lower risk of cardiovascular diseases and are hypothesized to regulate lipid metabolism. In this work, I optimized lipid extraction and chemical modification methods for analysis of fatty acids profile of tissue samples and biofluids using comprehensive two-dimensional gas chromatography coupled to mass spectrometry (GCxGC-MS). At first, I evaluated the relative amount of omega-3 fatty acids in red blood cells (Omega-3 index) of people living in Czech Republic in either the capital city (n=476) or the rural region (n=388). For this large-scale project, I extracted phospholipids from red blood cell (RBC) membranes, transesterified them into fatty acid methyl esters (FAMEs), and measured their profile by GCxGC-MS. The mean Omega-3 index was 3.56 mol % and I detected no significant...
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Regulation of lipogenesis in human adipose tissue: Effect of metabolic stress, dietary intervention and aging.
Šrámková, Veronika ; Rossmeislová, Lenka (advisor) ; Cahová, Monika (referee) ; Kuda, Ondřej (referee) ; Tanti, Jean-Francois (referee)
Adipose tissue (AT) is a complex organ specialised in safe storage and release of energy as lipids. The adipose organ is therefore essential for the maintenance of energy homeostasis. The prototypical cells of AT are adipocytes, emerging from the precursors in a process called adipogenesis. Adipogenesis itself is tightly connected with lipogenesis, i.e. with the synthesis of fatty acids and triglycerides. Various stimuli can disturb adipocyte differentiation and lipogenesis and thus contribute to AT dysfunction and development of associated metabolic diseases. This thesis was endoplasmicfocused on the investigation of lipogenesis in the context of reticulum stress (ERS), calorie restriction and aging. In Project A, we showed that exposition of adipocytes to high acute ERS inhibits expression of lipogenic genes and glucose incorporation into lipids. Moreover, chronic exposure of preadipocytes to ERS impaired both, lipogenesis and adipogenesis. On the other hand, chronic low ERS had no apparent effect on lipogenesis in adipocytes. These effects of ERS could therefore contribute to the worsening of AT function seen in obesity. The capacity of AT to store lipids decreases in aging, possibly due to the accumulation of senescence cells or higher ERS. In Project B, we investigated lipogenic capacity of...
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Effects of n-3 polyunsaturated fatty acids, rosiglitazone, low caloric diet and environmental pollutants: obesity and related disorders
Kuda, Ondřej
4. CONCLUSIONS Conceming the specific aims of the thesis, the following conclusions may be formulated: l.Additionalbeneficia|effectsofthecombinedfieatmentbyn_3PUFAof marine origin and anti-diabetic drug rosiglitazone on obesity and related disorders were proven in mice fed high-fed diet. In comparison with either n- 3 PUFA or TZD effects alone, the combined treatment was more potent in amelioration of the following adverse pheÍrotypes: a. body weight, body weight gain and body lipid content; b. dYsliPidaemia; c. muscle insulin resistance demonstrated as enhanced muscle glycogen synthesis; obesity-associated inflammation of adipose tissue; and inaddition,additiveinductionofadiponectinwasfound,especiallyits multimeric form, which induces insulin sansitivity' These results on mouse modet suggest possible application for human medicine, where fish oil concentrates may enhance efficacy ofthe treatment byTZD,and reduce the risk of the adverse effect of the TzD-therapy' 2. Relatively specific induction oflipid oxidation by n-3 PUFA in the intestine was found, which may be important for e'g' anti-obesity and hypolipidemic effects ofthese liPids. 3. Changes in adiponectin concentration as well as distribution of its multimeric forms as a result oflow caloric diet were found in human patients' 4. Association between...
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Structural and Functional Interactions of Mitochondrial ADP-Phosphorylating Apparatus
Nůsková, Hana ; Houštěk, Josef (advisor) ; Kolarov, Jordan (referee) ; Kuda, Ondřej (referee) ; Panicucci Zíková, Alena (referee)
The complexes of the oxidative phosphorylation (OXPHOS) system in the inner mitochondrial membrane are organised into structural and functional super-assemblies, so-called supercomplexes. This type of organisation enables substrate channelling and hence improves the overall OXPHOS efficiency. ATP synthase associates into dimers and higher oligomers. Within the supercomplex of ATP synthasome, it interacts with ADP/ATP translocase (ANT), which exchanges synthesised ATP for cytosolic ADP, and inorganic phosphate carrier (PiC), which imports phosphate into the mitochondrial matrix. The existence of this supercomplex is generally accepted. Experimental evidence is however still lacking. In this thesis, structural interactions between ATP synthase, ANT and PiC were studied in detail. In addition, the interdependence of their expression was examined either under physiological conditions in rat tissues or using model cell lines with ATP synthase deficiencies of different origin. Specifically, they included mutations in the nuclear genes ATP5E and TMEM70 that code for subunit ε and the ancillary factor of ATP synthase biogenesis TMEM70, respectively, and a microdeletion at the interface of genes MT-ATP6 and MT-COX3 that impairs the mitochondrial translation of both subunit a of ATP synthase and subunit Cox3...
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