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Nutritional Factors in Skeletal Muscle Insulin Resistance Development
Gojda, Jan ; Anděl, Michal (advisor) ; Saudek, František (referee) ; Prázný, Martin (referee)
Nutritional Factors in Skeletal Muscle Insulin Resistance Development Jan Gojda Abstract Background. Diet composition ranks among etiological factors of insulin resistance (IR) and diabetes. Vegans, people consuming exclusively plant-based diet, have significantly lower prevalence of IR and thus represent a suitable model population for study of nutritional factors on IR development. Branched chain amino acids (BCAA) ranks among these factors. Aims and hypothesis. Aim of the observational study was to prove that vegans have better glucoregulatory functions and thus to validate "vegan vs. omnivore" model. Aim of the consecutive interventional study was to prove in this model that dietary intervention with BCAA leads to a group sepcific changes in the insulin function mesures. Methods. 11 vegans and 10 omnivorous controls were recruited in the observational study. Hyperinsulinemic euglycemic clamp (HEC) and muscle (SM) biopsies (amount of intramyocellular lipids (IMCL), mtDNA and the activity of citrate synthase (CS)) were performed. 8 vegans and 8 omnivores were consequently subjected to the intervention with 15 or 20 g of BCAA respectively. The examination was performed at the baseline, after the intervention and after 6 months wash-out period: anthropometry, HEC, arginine test, SM biopsy (CS, activity of...
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Physiologic and pathophysiologic aspects of selected endocrinopathies. Their relationship to adipose tissue matebolism and insulin resistance
Ďurovcová, Viktória ; Kršek, Michal (advisor) ; Saudek, František (referee) ; Štich, Vladimír (referee)
The pathogenesis of insulin resistance is a complex and still intensively studied issue. Endocrine and paracrine activity of the adipose tissue together with mi- tochondrial dysfunction are the most discussed potential factors included in the development of insulin resistance. In the first part of our study we examined the involvement of the adipose tissue and its secretory products in the etiopathogenesis of insulin resistance in patients with Cushing's syndrome, acromegaly and simple obesity. We focused on three important regulators of metabolic homeostasis - fibroblast growth factors 21 and 19 (FGF-21 and FGF-19) and adipocyte fatty acid binding protein (FABP-4). We found significantly elevated circulating levels of FGF-21 and FABP-4 ac- companying insulin resistance in both patients with simple obesity and patients with obesity connected to Cushing's syndrome, as compared to healthy controls. The concentrations of both substances were comparable between hypercortisolic and obese patients. This finding together with the absence of correlation be- tween the levels of FGF-21 resp. FABP-4 and cortisol suggest that the reason for elevation of their concentrations is obesity and its metabolic consequences themselves rather then the effect of hypercortisolism on FGF-21 and FABP-4 production. We found no...
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The role of GH/IGF-1 axis components in the etiopathogenesis of metabolic disturbances in type 2 diabetes mellitus and acromegaly
Toušková, Věra ; Haluzík, Martin (advisor) ; Müllerová, Dana (referee) ; Saudek, František (referee)
(EN) GH/IGF-1 axis components (GH, growth hormone receptor (GH-R), IGF-1, IGF-1 receptor (IGF-1R), IGF-binding proteins (IGFBPs)) participate in the control of glucose metabolism, inflammatory processes as well as cell proliferation and differentiation, including adipocytes and monocytes. The aim of the present study was to evaluate the role of local mRNA expression of GH/IGF-1 axis components in subcutaneous adipose tissue (SCAT) and peripheral monocytes (PM) in the development of insulin resistance and differences of adipose tissue mass in following groups of patients: obese females with and without type 2 diabetes mellitus and subjects with active untreated acromegaly. A total number of 66 subjects were included in the study: obese females without type 2 diabetes mellitus (OB), obese females with type 2 diabetes mellitus (T2DM), acromegalic patients (AC) and healthy lean control subjects (C). T2DM underwent 2 weeks of very-low- calorie diet (VLCD - energy content 2500 kJ/day). According to our results we suggest that decreased mRNA expression of IGF-1, IGF-1R, IGFBP-2 and IGFBP-3 in adipose tissue of T2DM subjects may contribute to changes of fat differentiation capacity and the increased IGF-1R mRNA expression in peripheral monocytes in these patients may play a role in the regulation of...
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Immunointerventional therapy of autoimmune diabetes with recent oncet in NOD mice.
Vargová, Lenka ; Saudek, František (advisor) ; Štechová, Kateřina (referee) ; Mráz, Miloš (referee)
Introduction: Type 1 diabetes mellitus is a chronic metabolic disease caused by autoimmune destruction of pancreatic beta cells. The theory of the disease onset is derived from study of a disease course in non-obese diabetic (NOD) mice, in which the diabetes occurs due to a dysregulation of the immune system. Experimental and clinical studies showed that the autoimmunity may be abrogated by immune intervention, which if initiated early enough may at least slow down the ongoing beta cells lost and preserve residual insulin secretion. But immune intervention alone is not sufficient to restore normoglycemia in the majority of cases. Several interventional studies showed that stimulation of proliferation and/or regeneration of beta cells are necessary to restore normoglycemia in animal models. Aim of the study: To find out, if the combination of a potent immunosuppression (murine anti-thymocyte globulin (mATG), gusperimus) together with stimulation of islet regeneration (sitagliptin) will be able to slow down or reverse the course of the disease. Another aim is to identify the mechanism by which the substances act. Material and methods: All experiments were performed in female NODShiLtJ (H2g7 ) mice. The following parameters were examined at day 0, 7, 14 and 28: blood glucose, subpopulations of...
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BK-polyomavirus infection in patients after simultaneous pancreas and kidney transplantation
Mindlová, Martina ; Saudek, František (advisor) ; Forstová, Jitka (referee) ; Reischig, Tomáš (referee)
Introduction. The aim of the study was to introduce a new BKV PCR protocol in our centre and to verify its accuracy as well as to assess the prevalence, risk factors of BK virus replication, course of BKV infection and therapeutic approaches in simultaneous pancreas and kidney (SPK) recipients in order to design a screening protocol. Methods. The results analysed by both Affigene® and Transplantation Virology, Basel PCR protocols were compared. Thereafter 183 SPK patients were examined to assess the prevalence of BK viremia, viruria and BKVN and to identify the risk factors of BKV replication. The cases of retransplantation after a graft loss due to BKVN were retrospectively described. Results. 100 of results were analysed according to the Affigene ® and Transplantation Virology, Basel PCR protocols with the accordance of 95%, Rho = 0,946, 95% CI: 0.920 - 0.963, P<0,0001, Bland-Altman plot analyses: bias Basel PCR protocol/Affigene® BKV trender: -0,1 (mean) *±1.96 SD: -1,6 - 1,3] for both methods. Point-prevalence was assessed in 183 patients; Viruria found in 17,3 %, viremia in 3.8% of patients. High-level viruria >107 copies/mL detected in 3,7% of patiets, high-level virémia >104 in 1,6% of patients simultaneously with high-level viruria. BKVN was found in 0,5% of patients. Diabetes duration...
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Diagnostic contribution to the evaluation of intervention models in the treatment of type 1 diabetes
Zacharovová, Klára ; Saudek, František (advisor) ; Plecitá, Lydie (referee) ; Mandys, Václav (referee)
During treatment of diabetes mellitus by immunointervention or transplantation, it is necessary to monitor the markers of immune destruction or rejection of surviving insulin producing cells. An aim of this thesis is to improve the possibilities of following autoimmunity and to detect the survival of transplanted pancreatic islet in vivo. Partial aims included vitality testing of isolated islets for transplantation by measurement of respiration activity, observing the process of in vitro labeling of isolated islets with superparamagnetic iron oxide (SPIO) contrast agent for subsequent magnetic resonance imaging (MRI) of islets and observing SPIO particles transport after transplantation. We also studied a new dual paramagnetic contrast agent combined with fluorescein intended for identification of the MRI contrast agent in samples for histology. Further, we assessed autoimmune reaction by evaluation of cytokine response to specific stimulation with auto-antigens. We tried to affect beta-cells destruction by polyclonal anti- thymocyte antibodies in a mouse experimental model. A new method of the islet respiration measurement correlated with other methods of islet quality testing and it was suggested as a diagnostic test before clinical transplantation. Results obtained studying the intercellular...
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Possibilities of prediction and immunointervention in type 1 diabetes
Sklenářová, Jana ; Štechová, Kateřina (advisor) ; Saudek, František (referee) ; Pavlínková, Gabriela (referee)
Type 1 diabetes mellitus (T1D) is an organ-specific autoimmune disease characterised by autoimmune destruction of insulin-producing beta cells in the islets of Langerhans. It is a long-term process initiated months or even years prior to the clinical onset. The main role in the pathogenesis is played by T lymphocytes but other cell types are involved as well. The presence of autoantibodies in the circulation is typical even before the disease onset. Nowadays, intensive research is focused on finding individuals at risk and developing an effective prevention. During my postgraduate studies I was involved mainly in the research of T1D prediction and prevention. We investigated the relationship of established autoimmune markers - autoantibodies - and the cellular reactivity to GAD65 and IA2 autoantigens. We discovered that the reaction to autoantigens is very individual and it is influenced by the patient's autoantibody profile. These results could be relevant in planning antigen-specific immunointervention studies and improving their efficacy. We also made an attempt to improve specificity and sensitivity of a beta cell destruction marker (specifically demethylated DNA), which would enable better understanding of the beta cell decline and identification of individuals at risk of T1D development. In...
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Differentiation of pancreatic stem cells into insulin producing β-cells.
Leontovyč, Ivan ; Saudek, František (advisor) ; Štechová, Kateřina (referee) ; Holáň, Vladimír (referee)
Diabetes mellitus (DM) is a severe and frequent disease with increasing prevalence. It is not possible to achieve long term cure without late complications. Recent advances in cell fate modifications open a pathway to alternative cell therapies for DM cure. My doctoral thesis "Differentiation of pancreatic stem cells into insulin producing β- cells" is focused on the development of a new source of insulin secreting cells for transplantation. Combinatorial testing of numerous potential transcription factors and epigenetic modifiers resulted in a final protocol for the reprogramming pancreatic of exocrine cells into insulin secreting cells. The key transcriptional factors TF (Pdx1, Ngn3 a MafA) were applied in the form of synthetic mRNA. In four independent experiments we applied transcriptional factors in a specific sequence, thus obtaining 14.3 ± 1.9 % insulin positive cells. When challenged in vitro by the glucose levels of 2.5 and 20 mmol/l glucose, respectively, these cells exhibited glucose-sensitivity of insulin secretion (842 ± 72 and 1 157 ± 58 pg insulin/µg DNA/ml, n=5). They also demonstrated a sensitivity of insulin secretion (863 ± 78 and 1 025 ± 66 pg insulin/µg DNA/ml, n=5) to the concentration of depolarization agent KCl applied at 0 and 30 mmol/l, respectively together with 2.5...
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