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Hormonal synchronization of fetal circadian clocks in suprachiasmatic nuclei
Kapsdorferová, Viktória ; Sumová, Alena (advisor) ; Sehadová, Hana (referee)
Rhythmic non-light maternal signals, such as various behavioral, neurohumoral or metabolic factors, may play a key role in synchronization of the fetal circadian clock. This diploma thesis focuses more closely on the possible role of leptin and dopamine in the hormonal synchronization of the fetal central clock resides in the suprachiasmatic nuclei of the hypothalamus. A transgenic mouse fetus, which has luciferase fused to the clock gene Period 2, was used as an experimental model. This allowed us to monitor the operation of the fetal central clock in real time by recording the bioluminescence of tissue explants. Exogenous administration of dopamine during the decline in bioluminescence at normalized circadian time 15 induces larger phase delays compared to vehicle. Leptin, on the other hand, can participate in the development of spontaneous rhythms by stabilizing the integrity of the circadian rhythm, manifested by slowing down the rhythm dampening. At the level of individual cellular oscillators, significant regional differences in amplitude and period were not observed using bioluminescence microscopy. However, a slight dispersion of cell phases was observed after administration of dopamine during decreasing bioluminescence. In the case of leptin, there was a prolongation of period of the cell...
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Circadian rhythms in adipocytes and impact of their disruption
Zavřelová, Michaela ; Sumová, Alena (advisor) ; Spišská, Veronika (referee)
This bachelor thesis deals with circadian rhythms in adipocytes and the consequences of their disruption. The thesis summarizes current scientific knowledge and explores the mechanism of rhythm control at the molecular level, which is formed by transcriptional translational feedback loops. Adipocytes control lipid metabolism through the production of adipokines, adipogenesis, lipogenesis, and lipolysis. The research focuses on how clock genes are involved in these processes. All of these events, which are characteristic of adipocytes, are highly regulated and the genes that are involved in them are transcriptionally activated by clock gene proteins. Circadian rhythms are an integral part of our lives, and desynchronization of rhythms between the main oscillator, which is the suprachiasmatic nuclei, and peripheral adipocytes can lead to metabolic disorders, which in turn can lead to obesity, insulin resistance, or type 2 diabetes. Obesity is one of the biggest problems of modern society, and disrupted circadian rhythms due to today's lifestyle are one of the causes of its development. Key words: circadian rhythms, clock genes, adipocytes, obesity, PPARγ, adipogenesis, lipogenesis, lipolysis, leptin, adiponectin
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Acipimox during Short-Term Exercise Exerts A Negative Feedback of Growth Hormone on Ghrelin Secretion in Patients with Bulimia Nervosa and in Healthy Women: The Role of Lipolysis
Smitka, Kvido ; Nedvídková, Jara (advisor) ; Kršek, Michal (referee) ; Čáp, Jan (referee)
Title: Acipimox during Short-Term Exercise Exerts A Negative Feedback of Growth Hormone on Ghrelin Secretion in Patients with Bulimia Nervosa and in Healthy Women: The Role of Lipolysis Objective: Eating disorders, such as bulimia nervosa (BN) and anorexia nervosa (AN), are characterized by abnormal eating behavior. The main features of BN are binge-eating and inappropriate compensatory methods to prevent weight gain. The appetite-modulating peptide ghrelin is secreted by the stomach and shows a strong release of growth hormone (GH). A potential GH-ghrelin feedback loop between stomach and the pituitary has been recently reported. Acipimox (Aci), an analogue of nicotinic acid, inhibits lipolysis in adipose tissue (AT) and reduces plasma glycerol and free fatty acids (FFA) levels. Exercise and Aci are stimulators of GH secretion. We suppose that a negative feedback from increased GH levels during exercise may play a role in reducing plasma ghrelin levels. We surmised that altered baseline activity and exercise-induced activation of the sympathetic nervous system (SNS) results in excessive stimulation of lipolysis associated with negative energy balance and may lead to abnormal AT metabolism in patients with BN. Disruption of the gut-brain-AT axis might be involved in the pathogenesis of BN. The...
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Vztah SNP v genu pro leptin a parametrů vnitřního prostředí býků Českého strakatého skotu
Lysáková, Eva
There is a lot of factors which has impact on quality of bovine meat. The aim of this thesis was to examine correlations between chosen SNPs in leptin gene and specific hormones and metabolites, which have influence on the meat quality and also complete health condition of beef. There were 99 bulls of Czech Fleckvieh cattle used for this study. The examined parameters were insulin, glucose, cholesterol, triacylglycerol, non-esterified fatty acids and betahydroxybutiric acid. There was shown no statistically signifiant correlation between leptin gene polymorfisms and observed parameters. Only proved correlation was between leptin and cholesterol and glucose. There is lot of other factors involved in changes of amount of these substances though.
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The role of nitric oxide during embryonic wound healing and regeneration
Abaffy, Pavel ; Šindelka, Radek (advisor) ; Brábek, Jan (referee) ; Krylov, Vladimír (referee)
The study of the mechanisms that control wound healing is an attention-drawing area within the fields of biology and medicine. Wound healing can be usually defined as two basic types. The first type is adult wound healing, which is slow and results in the scar formation. The second type is referred to as embryonic wound healing, which is in contrast fast and scarless. Wound healing is a complicated process that includes many steps, which are regulated by various types of molecules. One of these important molecules is nitric oxide (NO). Its function is usually connected with the regulation of inflammation and angiogenesis during adult wound healing. However, there is currently no information on its role during embryonic wound healing, where the immune and vascular systems are not yet developed. In this work, we explore and describe the role of the NO during the healing of the early embryos. The highest concentration of the NO post wounding is produced during the first 30 minutes after injury. This applies to all developmental stages, from the blastula stage all the way to the swimming tadpole stage. The main role of the NO during embryonic wound healing is the regulation of the gene expression that is connected with the stress response and the regulation of cellular metabolism. Additionally, we...
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Sleep related neurohumoral regulation of weight management
Havelková, Jarmila ; Tomešová, Jitka (advisor) ; Suchánek, Pavel (referee)
Over the past three decades, it has been confirmed that the alarming increase in number of obese patients is related to the sleep duration and its quality. Neurohumoral response to short sleep duration and poor sleep quality leads to decreased levels of melatonin, leptin and orexin, asto increased levels of cortisol, ghrelin and neuropeptide Y. Such an inaccurate regulation contributes both to excessive intake of energy-dense diet and to the reduction of energy expenditure during physical activity. The bachelor thesis summarizes recent information about the relationship of sleep and obesity, focusing on hormones and peptides involved in the regulation of energy balance processes, including the posssibility to use their mechanisms for weight control.
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Vliv genotypů pro gen leptin na vybrané kvalitní ukazatele hovězího masa
BENEŠ, Karel
The dissertation "The Influence of Genotype of Leptin Gene on Qualitative Characteristics of Beef" describes the effect of polymorphisms of gene of leptin on selected qualitative, morphometric and weight indicators of beef and carcass. The analysis was carried out on 333 bulls of Czech Fleckvieh, which were genotyped (by PCR/RFLP method) of chosen locus. This locus is associated with qualitative changes in beef according to previous foreign studies. The weight of carcass, fore and hind quarter of the right half of the carcass, the weight of the individual tissues (meat, bone, and fat) and the weight of main meaty parts from the right half of carcass were measured. Before the dissection chosen morphometric indicators were measured. After the dissection, a sample of the musculus longissimus lumborum et thoracis was taken and then analysed in the laboratory. Basic chemical composition (dry matter, fat content, protein, and ash), muscle fibers diameter and fatty acid profile was determined. In addition, pH, added water holding capacity, colour (CIE Lab colour coordinates) were analysed both for one-day post-mortem and after 14 days of ageing. The shear force (using the Warner-Bratzler probe) was evaluated at the same time intervals as for both raw and heat-treated samples by grilling. The studied LEP polymorphism had a statistically significant effect on the weight of the hot carcass, the weight of right half of carcass and fore and hind quarter. LEP polymorphism significantly affected the proportion of meat on the right half of carcass, the weight of the bones and total weight of the I. class meat, and the weight of the I. class meat in the fore quarter. Further, the effect of LEP polymorphism on the weight of boneless round, boneless chuck, plate, flank, rib, hind shank, and meat trimmings of fore quarter was found. In a group of morphometric indicators, the effect was significant on lengths of round, fullness of round and round circumference. In the case of chemical composition, the effect of LEP polymorphism on the intramuscular fat content was significant. From the qualitative indicators, the effect was significant on the pH value and added water holding capacity, both one-day post-mortem and after 14 days of ageing. In the case of tenderness, the effect on shear force of heat treated, non-aged meat was significant. From the indicators describing colour, a statistically significant effect on the indicator of lightness was found in the case of unconditioned meat and after 14 days of ageing the effect was significant on the indicator characterising yellow colour and the colour saturation. Determination of fatty acid profile was carried out by gas chromatography. The effects of studied polymorphism and differences between LEP genotypes were found in myristic, palmitic, palmitoleic, linoleic, -linolenic, -linolenic, conjugated linoleic, eisocapentaenoic, docosatetraenoic, docosapentaenoic both n-6 and n-3 and docosahexaenoic acids. From aggregated indicators, the statistical significant effect of LEP polymorphims on PUFA content, omega-3 fatty acids content, and omega-6/omega-3 fatty acids ratio was found. In connection with other candidate gene loci influencing the quality of beef, the results of dissertation can be used in the preparation of breeding schemes aimed at the production of quality breeding animals, highlighting the higher quality standards of the produced meat.
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The impact of obesity on the immune system with a focus on NK cells
Císařová, Radka ; Krulová, Magdaléna (advisor) ; Černý, Jan (referee)
Obesity is expanding rapidly even in developing countries and has negative effect on human health. The emerging low-grade chronic inflammation of visceral adipose tissue is generally accepted as the cause of this negative effect. The most important factor in the inflammation development is the induction of inflammatory phenotype of macrophages and their subsequent accumulation in visceral adipose tissue. The first impulse for these changes is ambiguous but can be associated with changes in phenotype and activation status of NK cells. NK cell mediated cytotoxicity against viral infected or cancer cells is impaired by obesity. Leptin level is chronically elevated in obesity and has the counter effects on NK cells. Short-term leptin exposure causes lower cytotoxicity of NK cells but long-term leptin exposure has opposite effect. The few studies about phenotype of NK cells in visceral adipose tissue during obesity point on higher production of INF- and expression of NKG2D by NK cells. Further studies of NK cell phenotype in the context of obesity and in particularly in the context of visceral adipose tissue of obese subjects are important for understanding the negative effect of obesity.
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Vztah polymorfismu UASMS1 v genu leptin s ukazateli kvality masa
Moravanská, Andrea
The aim of this thesis was to perform association analysis of UASMS1 polymor-phism in leptin gene with parameters of beef quality, studied on a group of Czech Fleckvieh bulls. The group of 236 bulls was genotyped by direct sequencing of the PCR product. Individual genotypes were processed into a database and statistical evaluation of association was performed by using SAS software. The UASMS1 polymorphism had a highly significant effect on palmitoleic acid content (p = 0.00006) and stearic acid content (p = 0.0005) between CT and TT genotypes. There was a significant value in myristoleic acid content (p = 0.0117) between genotypes CT and TT and in linolelaidic acid content between both genotypes CC and CT (p = 0.0340) and CC and TT (p = 0.0417). Values relating to the effect on dry matter content (p = 0.0746) and colour of meat (p = 0.0541) had only approaching evidentiary values. The influence of genotype on intramuscular fat content or other parameters of beef quality has not been demon-strated in this study.
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Energetický metabolismus inbredních myších linií a jeho ovlivnění dietou
Kůs, Vladimír ; Kopecký, Jan (advisor) ; Nováková, Olga (referee) ; Mráček, Tomáš (referee)
Obesity and associated metabolic disorders, called as "metabolic syndrome", currently represent a major social and economical problem of public health. From the energy balance point of view, long-lasting energy surplus leads eventually to massive accumulation of energy stores resulting in various adverse effects on metabolism and health. General goal of the thesis was to examine these metabolic disorders at cellular and whole-body level using suitable mouse models. The main focus was on the most metabolically active tissue, namely skeletal muscle, liver and adipose tissue and on the regulatory roles of AMP-activated protein kinase (AMPK) and leptin in the energy metabolism. The whole thesis is based on four published studies. Two studies were focused on skeletal muscle. In the first study, we proved the involvement of leptin and AMPK in the metabolic response to high-fat diet-feeding. We described a mechanism of muscle non- shivering thermogenesis based on enhanced lipid catabolism, which contributes to the genetically-determined resistance of inbred A/J mice to obesity. Such mechanism was not operating in obesity-prone C57BL/6 mice. In the second study, performed using C57BL/6 mice, we have described beneficial effect of combination treatment using n-3 polyunsaturated fatty acids (n-3 PUFA) of...
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