Hepcidin, a key regulator of iron metabolism, plays a crucial role in the pathogenesis of anemia of chronic disease. Although it is produced mainly in the liver, its recently described expression in adipose tissue has been shown to be enhanced in massive obesity due to chronic low-grade inflammation. Our objective was to study the changes in hepcidin expression in adipose tissue during acute-phase reaction. We measured hepcidin mRNA expression from isolated subcutaneous and epicardial adipose tissue at the beginning and at the end of the surgery. The expression of mRNAs for hepcidin and other iron-related genes (transferrin receptor 1, divalent metal transporter 1, ferritin, ferroportin) were measured by real-time RT-PCR. Hepcidin expression significantly increased at the end of the surgery in subcutaneous but not in epicardial adipose tissue. Apart from the increased levels of cytokines, the parameters of iron metabolism showed typical inflammation-induced changes. We suggest that acute inflammatory changes could affect the regulation of hepcidin expression in subcutaneous adipose tissue and thus possibly contribute to inflammation-induced systemic changes of iron metabolism., M. Vokurka ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Critical illness induces among other events production of proinflammatory cytokines that in turn interfere with insulin signaling cascade and induce insulin resistance on a postreceptor level. Recently, local renin-angiotensin system of adipose tissue has been suggested as a possible contributor to the development of insulin resistance in patients with obesity. The aim of our study was to determine local changes of the renin-angiotensin system of subcutaneous and epicardial adipose tissue during a major cardiac surgery, which may serve as a model of an acute stress potentially affecting endocrine function of adipose tissue. Ten patients undergoing elective cardiac surgery were included into the study. Blood samples and samples of subcutaneous and epicardial adipose tissue were collected at the beginning and at the end of the surgery. Blood glucose, serum insulin and adiponectin levels were measured and mRNA for angiotensinogen, angiotensin-converting enzyme and angiotensin II type 1 receptor were determined in adipose tissue samples using RT PCR. Cardiac surgery significantly increased both insulin and blood glucose levels suggesting the development of insulin resistance, while serum adiponectin levels did not change. Expression of angiotensinogen mRNA significantly increased in epicardial adipose tissue at the end of surgery relative to baseline but remained unchanged in subcutaneous adipose tissue. Fat expression of angiotensin-converting enzyme and type 1 receptor for angiotensin II were not affected by surgery. Our study suggests that increased angiotensinogen production in epicardial adipose tissue may contribute to the development of postoperative insulin resistance., T. Roubíček, M. Dolinková, J. Bláha, D. Haluzíková, L. Bošanská, M. Mráz, J. Křemen, M. Haluzík., and Obsahuje bibliografii a bibliografické odkazy
PPAR-α agonists improve insulin sensitivity in rodent models of obesity/insulin resistance, but their effects on insulin sensitivity in humans are less clear. We measured insulin sensitivity by hyperinsulinemic-isoglycemic clamp in 10 obese females with type 2 diabetes before and after three months of treatment with PPAR-α agonist fenofibrate and studied the possible role of the changes in endocrine function of adipose tissue in the metabolic effects of fenofibrate. At baseline, body mass index, serum glucose, triglycerides, glycated hemoglobin and atherogenic index were significantly elevated in obese women with type 2 diabetes, while serum HDL cholesterol and adiponectin concentrations were significantly lower than in the control group (n=10). No differences were found in serum resistin levels between obese and control group. Fenofibrate treatment decreased serum triglyceride concentrations, while both blood glucose and glycated hemoglobin increased after three months of fenofibrate administration. Serum adiponectin or resistin concentrations were not significantly affected by fenofibrate treatment. All parameters of insulin sensitivity as measured by hyperinsulinemic-isoglycemic clamp were significantly lower in an obese diabetic group compared to the control group before treatment and were not affected by fenofibrate administration. We conclude that administration of PPAR-α agonist fenofibrate for three months did not significantly affect insulin sensitivity or resistin and adiponectin concentrations in obese subjects with type 2 diabetes mellitus. The lack of insulin-sensitizing effects of fenofibrate in humans relative to rodents could be due to a generally lower PPAR-α expression in human liver and muscle., K. Anderlová, R. Doležalová, J. Housová, L. Bošanská, D. Haluzíková, J. Křemen, J. Škrha, M. Haluzík., and Obsahuje bibliografii a bibiografické odkazy