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Regulation of immunometabolism in white adipose tissue
Gazdová, Tatiana ; Horáková, Olga (advisor) ; Beňová, Andrea (referee)
High-fat diet promotes the development of diet-induced obesity, which leads to further complications such as insulin resistance and type II diabetes. The underlying cause for development of obesity associated pathologies is disruption of adipose tissue homeostasis. Excessive lipid accumulation and rapid white adipose tissue expansion stimulate infiltration, proliferation, and activation of immune cells involved in inflammation propagation. Immune cells within white adipose tissue have the ability to modulate adipocyte function as well as whole-body metabolism. These interactions and function modulations are the core topics of immunometabolism, a rapidly developing field of research focused on interpreting how immune system modulates metabolism on cellular as well as systemic level. In obesity, pro-inflammatory immune cells, for example M1 macrophages and neutrophils, outnumber homeostasis-promoting anti-inflammatory immune cells in white adipose tissue and alter the tissue environment. As a result, pro-inflammatory cytokines prevent adipocytes from adequately responding to extracellular stimuli. The resulting interactions between immune cells and adipocytes maintain inflammation and promote ectopic lipid accumulation. Experimental studies suggest that white adipose tissue inflammation can be...
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Characterization of metabolic effects of dietary omega-3 fatty acids in transgenic PPARα-humanized mice
Kalendová, Veronika ; Rossmeisl, Martin (advisor) ; Šilhavý, Jan (referee)
Obesity is tightly connected with metabolic diseases including insulin resistance, type 2 diabetes or dyslipidemia. Peroxisome proliferator-activated receptor (PPAR)-α is a key transcription factor involved in the regulation of lipid metabolism, while its activity is stimulated by a variety of hypolipidemic drugs. n-3 polyunsaturated fatty acids (PUFA), including eicosapentaenoic (EPA) and docosahexaenoic (DHA) acid, are endogenous ligands of PPARα, and they are used in the form of fish oil as dietary supplements in order to lower blood lipid levels and to prevent cardiovascular disease. Wax esters represent a novel lipid form of EPA and DHA, and according to recent studies they could exert more potent effects than the classical fish oil (i.e. triacylglycerols). Mice of the 129S1/SvImJ inbred strain were used in the present experiment, and included wild-type (WT) mice, as well as transgenic mice either with the exclusive expression of the human form of PPARα (hPPARα) or mice completely lacking PPARα (PPARα-KO). Mice were fed for 8 weeks the following diets: (i) a control low-fat diet, (ii) obesogenic high-fat diet (cHF), and (iii) the cHF diet supplemented with the n-3 PUFA concentrate in the form of wax esters isolated from marine zooplankton Calanus finmarchicus (ω3Cal). Mice were subjected to...
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Metabolic effects of chronic metformin administration in obese mice depending on the composition of high-fat diet
Roubalová, Jana ; Rossmeisl, Martin (advisor) ; Vybíral, Stanislav (referee)
Obesity leads to many severe metabolic disorders, e.g. dyslipidemia, insulin resistance, ectopic fat accumulation in the liver and skeletal muscles, non-alcoholic fatty liver disease and finally diabetes mellitus type 2. Metformin (1,1-dimethylbiguanide) is the most favored medicament for the treatment and prevention of these disorders. It stimulates cellular glucose uptake and normalizes blood levels of lipid metabolites without triggering insulin secretion. Research on insulin resistance and diabetes is often realized through developing diet- induced obesity in laboratory animals. The aim of this project is to compare metabolic effects of two different high-fat diets named HFD and HSD. The HFD diet consists chiefly of n-6 polyunsaturated fatty acids (corn oil) and starch (100% glucose). The HSD diet contains mainly saturated fatty acids (lard) and sucrose (50% glucose and 50% fructose). I also studied metabolic effects of metformin by adding it continuously to the drinking water given to obese mice fed with the HFD or the HSD diet. Methods: Intraperitoneal glucose tolerance test (IPGTT), blood and tissue levels of lipid metabolites assessment, radio-immunological assessment of blood levels of insulin, assessment of AMPK activity in liver by western blotting. Results: Increased consumption of the...
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