National Repository of Grey Literature 7 records found  Search took 0.01 seconds. 
Molecular mechanisms of iron transport across plasma membrane in mammalian cells
Balušíková, Kamila ; Kovář, Jan (advisor) ; Ehrmann, Jiří (referee) ; Krijt, Jan (referee)
Iron belongs among the trace elements and its role in humans is irreplaceable. Up to 5 g of iron can be found in adult body distributed among different compounds. Iron ions are therefore essential to all cells of our body and its homeostasis is thoroughly controlled. Iron uptake into the organism is mediated by enterocyte cells in the small intestine, where heme as well as non-heme forms of iron are absorbed. Non-heme iron is absorbed via Dcytb (duodenal cytochrome b), DMT1 (divalent metal transporter 1), ferroportin, hephaestin, and ceruloplasmin molecules. Although these molecules can also participate in non-transferrin- bound iron transport across plasma membranes within the whole organism, mechanisms of this transport are not yet fully elucidated. The aim of the present work was to contribute to our understanding of molecular mechanisms that are involved in non-transferrin-bound iron transport across the plasma membrane of mammalian cells. Our project was focused on the description of non-transferrin- bound iron transport in human cells in vitro and in vivo under conditions of iron deficiency or iron overload. Transformed cell lines, that represent the three main types of cells involved in iron homeostasis, and tissue samples of duodenal biopsies were used as experimental models. The expression...
Cell death as a result of iron-induced cellular damage
Běhounek, Matěj ; Balušíková, Kamila (advisor) ; Truksa, Jaroslav (referee)
Iron is an essential trace element for almost all living organisms. Iron overload in cells and tissues, however, leads to their disruption. Most oftenly damaged are parenchymatic organs such as the liver, pancreas and heart. The aim of this thesis was to create cellular in vitro models for the investigation of effects of excess iron on hepatocytes and pancreatic beta cells and on these models to investigate cellular processes which lead to cellular damage during iron overload. We focused on examining the presence of oxidative and endoplasmic reticulum stress and the activation of apoptotic cell death. For our experiments, we used HEP-G2 cell line which represents human hepatocytes and NES2Y cell line which represents human pancreatic beta cells. To study the mechanisms of cellular damage during iron overload, we used two approaches by which we observed both acute and long-term effects of high levels of iron on damage of the tested cell lines. When studying the acute effect of excess iron on the cells, we applied high doses of iron (using 15 mM ferric citrate in medium) that led to the activation of cell death in hours. Long-term effects of iron overload were tested on cells regularly cultivated in the presence of 50 μM and 100 μM ferric citrate over a period of several months. Iron concentrations...
Extracellular microRNAs and their role in pathologies especially in the field of gynecology and obstetrics.
Štěrbová, Monika ; Hromadníková, Ilona (advisor) ; Balušíková, Kamila (referee)
microRNAs (miRNAs) represent a relatively newly discovered group of RNA molecules and they serve to regulate gene expression. In spite of processes of differentiation, proliferation and apoptosis, miRNAs influence the whole biological systems, such as embryogenesis, oncogenesis, and immunity. There have been a number of experiments in recent years concerning diagnoses and predictions of complications during pregnancy, and tumour growth. Extracellular miRNA molecules participating in circulation of patients are used in the non-invasive diagnostics. RNA molecules usually get into the extracellular fluid during the apoptosis process. I chose four diseases, which extracellular miRNA have diagnostic potential - preeclampsia, intrauterine growth retardation, gestational diabetes mellitus and breast cancer - for my work. An aberrant expression of different levels of various extracellular miRNAs has been reported in these diseases but the clinical use of microRNAs in the diagnosis and prediction of those still requires further research and optimization. Keywords: breast cancer, extracellular nucleic acids, fetal growth retardation, gestational diabetes mellitus, microRNA, PCR, preeclampsia
Effect of iron overload on the induction of apoptosis in mammalian cells
Kabíčková, Tereza ; Balušíková, Kamila (advisor) ; Klíma, Martin (referee)
Iron cations are an important metal ions required to number of essential cell functions. On the other hand, ferrous iron can be very toxic as well. When surplus iron is present in cells, it can catalyze the formation of reactive oxygen species (especially hydroxyl radicals) by Fenton reaction. Iron homeostasis is predominantly regulated by very strict mechanisms on the level of iron uptake into the body. Moreover, iron absorption, transport and storage within the body can be also regulated using complex mechanisms which differ on the level of individual cells and on the level of whole organism. Deregulation of iron homeostasis causing an iron overload and generation of reactive oxygen radicals can evoke serious cell damage leading up to apoptotic cell death. Excess iron storage and subsequent development of oxidative stress can affect lot of different tissues in the body. The organ damages such as fibrosis, cirrhosis, hepatocellular carcinoma, heart failure, loss of β cells and glucose intolerance or diabetes mellitus in patients with iron overload are very often seen. Nevertheless, the apoptosis induced by iron overload has not been well elucidated yet. There are no complex informations about the precise mechanism by which oxidative stress affects different cell types or whether there are other...
Effect of the availability of iron compounds on the expression of molecules involved in the transport of non-transferrin iron ions: In vitro study concerning human cell lines K562 and Caco-2
Balušíková, Kamila
Iron absorption, transport, and storage in the body is very strictly regulated mechanism by the reason of absence of a controlled pathway provided its excretion. Hence we are interested in transport mechanism of non-haem iron which is mediated by molecules DMT1 (divalent metal transporter 1, membrane iron importer), Dcytb (duodenal cytochrom b, membrane ferrireductase), ferroportin 1 (membrane iron exporter), hephaestin (membrane ferroxidase) and ceruloplasmin (cytoplasmatic ferroxidase) and enable iron uptake from food up to its binding to plasma transferrin. Our project monitors the effect of iron availability to the expression of the molecules potentially involved in non-transferrin iron transport across cell membranes. We studied the influence of iron deficiency and iron overload to the regulation of iron uptake by these molecules in various functional types of human cells. Cells were maintained in RPMI 1640 medium and supplemented with other additives. The expression was tested on mRNA level by quantitative real-time PCR with reverse transcription in in vitro study using human cell lines K562 and Caco-2. K562 cells (human erythroleukemia) represent cells with high utilization of no-transferrin iron and Caco-2 cells (human colorectal carcinoma) is a model of cells with different apical and...

Interested in being notified about new results for this query?
Subscribe to the RSS feed.