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Adipocytokines released by the adipose tissue play an important role in the regulation of immune and inflammatory responses. In case of obesity their production is badly regulated, which is one of the major factors contributing to the onset of a chronic low-grade overall inflammatory response. This response represents a risk factor for the progression of other diseases, such as atherosclerosis or type-2 diabetes. The main goal of this thesis consisted in comparing the secretion of selected adipocytokines (adiponectin, IL6 and MCP1), isolated from the adipose tissue prior to and after a dietary intervention, and this under basal conditions and during stimulated lipolysis. Based on the same profile, the secretion of the isoforms of adiponectin was compared subsequently. The concentration of adiponectin, IL6 and MCP1 was determined by the ELISA method, the Western Blot method was used to determine the distribution of the adiponectin isoforms. The thesis also concentrates on the gene expression of ATF3, ATF4 and HSPA5, factors engaged in the ER stress in the course of the differentiation of adipocytes. The changes in the gene expression were measured by the quantitative Real Time PCR method. To prove the correct process of the differentiation the genes aP2 and PPARg were used. Within the framework of...

The accumulation of unfolded or misfolded proteins in endoplasmic reticulum (ER) leads to ER stress and the activation of unfolded protein response (UPR). Recent studies show that ER stress or UPR are associated with many diseases such as diabetes, hepatitis type C, prion disease, different kinds of tumors or Alzheimer's, Parkinson's and Huntington's disease and also with physiological processes like cell differentiation. When UPR is activated in yeast Saccharomyces cerevisiae, Ire1 protein oligomerizes, transautophosphorylates and activates itself. After this, Ire1 cleaves HAC1 mRNA to remove an intron. The spliced form of HAC1 mRNA is translated into the Hac1 transcription factor, which induces transcription of genes for chaperones of lumen ER, proteins involved in ERAD, synthesis of lipids etc. The cell uses this to reestablish homeostasis in ER. In mammals, the UPR is more complex and except Ire1 dependent pathway, it comprises Perk and Atf6 pathways, which are missing in yeast. Nevertheless, Perk is activated and regulated by the similar mechanism as Ire1 in S. cerevisiae. In consideration of broad spectrum of methods for genetic manipulation, rapid growth and well annotated genome, the yeast S. cerevisiae is a useful model for study of general mechanisms of UPR in mammals.