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Characterization of energy metabolism of murine models of obesity
Irodenko, Ilariia ; Bardová, Kristina (advisor) ; Šilhavý, Jan (referee)
Energy metabolism involves processes of energy intake and energy expenditure, including storage of excessive energy in a form of lipids. White adipose tissue stores energy and plays an important role in maintenance of energy homeostasis. Animals obtain energy by oxidation of substrates from diet. Indirect calorimetry is a method for assessment of energy expenditure based on a measurement of oxygen consumption and carbon dioxide production. The VCO2/VO2 ratio (Respiratory Quotient) indicates oxidation of specific metabolic substrates. Metabolic flexibility is the ability of an organism to match substrate oxidation to its availability. The decrease of a metabolic flexibility is linked to inability to adapt to available substrate and with excessive lipid storage in the body. In this thesis we evaluated correlation between the metabolic flexibility defined by indirect calorimetry and the adipose tissue metabolism in two strains of mice, C57Bl/6J and AJ, that differ in their propensity to diet-induced obesity. Increased whole-body metabolic flexibility in A/J mice was connected to higher ability of adipose tissue to release and uptake lipids. The study of reaction to high-fat diet enables us to distinguish "metabolically healthy" and "metabolically unhealthy" adipose tissue. The knowlegde of these...
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Regulation of lipolysis and re-esterification in white adipose tissue - possible role of FGF21
Špiláková, Blanka ; Zouhar, Petr (advisor) ; Šilhavý, Jan (referee)
Fibroblast growth factor 21 (FGF21) is a unique peptide hormone involved in the energy homeosta- sis, as well as in the regulation of glucose and lipid metabolism. Numerous animal studies suggest that FGF21 may be used as a potential treatment for obesity and type 2 diabetes mellitus. It was found out, that FGF21 counteracts the development of obesity presumably by increasing energy expenditure through activation of thermogenesis in brown and white adipose tissue. FGF21 apparently also inhibits lipolysis. However, the specific mechanism of action of FGF21 is not clear. In our experiments we studied the antiobesogenic effects of FGF21 on mice model of diet-induced obesity at thermoneutrality. It is assumed that this model approach (in contrast to housing mice at standard laboratory temperature) mimics closely the metabolic status of humans. During the 4- to 8-day FGF21 treatment we observed a gradual reduction of lipid content in the brown and white adipose tissue and liver, especially in combination with β3-adrenergic stimulation. We have confirmed that FGF21 inhib- its lipolysis and also stimulates browning in certain adipose tissue depots. Furthermore, we have found that the effect of FGF21 on fatty acid secretion by adipose tissue is not mediated by changes in the fatty acid re-esterification...
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Characterization of energy metabolism of murine models of obesity
Irodenko, Ilariia ; Bardová, Kristina (advisor) ; Šilhavý, Jan (referee)
Energy metabolism involves processes of energy intake and energy expenditure, including storage of excessive energy in a form of lipids. White adipose tissue stores energy and plays an important role in maintenance of energy homeostasis. Animals obtain energy by oxidation of substrates from diet. Indirect calorimetry is a method for assessment of energy expenditure based on a measurement of oxygen consumption and carbon dioxide production. The VCO2/VO2 ratio (Respiratory Quotient) indicates oxidation of specific metabolic substrates. Metabolic flexibility is the ability of an organism to match substrate oxidation to its availability. The decrease of a metabolic flexibility is linked to inability to adapt to available substrate and with excessive lipid storage in the body. In this thesis we evaluated correlation between the metabolic flexibility defined by indirect calorimetry and the adipose tissue metabolism in two strains of mice, C57Bl/6J and AJ, that differ in their propensity to diet-induced obesity. Increased whole-body metabolic flexibility in A/J mice was connected to higher ability of adipose tissue to release and uptake lipids. The study of reaction to high-fat diet enables us to distinguish "metabolically healthy" and "metabolically unhealthy" adipose tissue. The knowlegde of these...
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Regulation of lipolysis and re-esterification in white adipose tissue - possible role of FGF21
Špiláková, Blanka ; Zouhar, Petr (advisor) ; Šilhavý, Jan (referee)
Fibroblast growth factor 21 (FGF21) is a unique peptide hormone involved in the energy homeosta- sis, as well as in the regulation of glucose and lipid metabolism. Numerous animal studies suggest that FGF21 may be used as a potential treatment for obesity and type 2 diabetes mellitus. It was found out, that FGF21 counteracts the development of obesity presumably by increasing energy expenditure through activation of thermogenesis in brown and white adipose tissue. FGF21 apparently also inhibits lipolysis. However, the specific mechanism of action of FGF21 is not clear. In our experiments we studied the antiobesogenic effects of FGF21 on mice model of diet-induced obesity at thermoneutrality. It is assumed that this model approach (in contrast to housing mice at standard laboratory temperature) mimics closely the metabolic status of humans. During the 4- to 8-day FGF21 treatment we observed a gradual reduction of lipid content in the brown and white adipose tissue and liver, especially in combination with β3-adrenergic stimulation. We have confirmed that FGF21 inhib- its lipolysis and also stimulates browning in certain adipose tissue depots. Furthermore, we have found that the effect of FGF21 on fatty acid secretion by adipose tissue is not mediated by changes in the fatty acid re-esterification...
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