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The role of growth factors and cytokines in regulation of mammalian oocyte maturation
Marcollová, Kateřina ; Procházka, Radek (advisor) ; Vávra, Jiří (referee)
Reproduction is key for species survival. Oocytes are blocked in prophase I of meiosis in follicle. Gonadotropin stimulation leads to follicle growth and competent oocyte. First polar body extrusion is a sign of meiotic division resumption. Oocyte is blocked at prophase I by a high cAMP level, activating PKA, that inhibits MPF. CNP binds to NPR2, that stimulates the generation of cGMP in granulosa cells, which diffuses to oocyte where it competes with cAMP on PDE3A. LH and FSH released from pituitary gland initiates signaling cascade restoring meiotic division. Synthesis of AREG, EREG and BTC activates EGFR and MAPK pathways in somatic cells which contribute to reduction of gap junction permeability, lowering NPR2 activity, that leads to reduction of cGMP production and transport. Less cGMP diffuses to oocytes, which leads to PDE3A activation and cAMP hydrolysis. This causes MPF activation and meiotic division resumption. MAPK together with PI3K participate on increasing production of hyaluronic acid, thereby cumulus cells expansion and oocyte ovulation. Oocyte maturation and growth is improved with utilization of in vitro technics and oocyte cultivation with growth factors and cytokines. FLI medium, combining FGF2, LIF and IGF-1, increases oocyte cultivation success and blastocyst quality of farm...
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Preparation, characterization and testing of blood derivatives for applications in regenerative medicine
Sovková, Věra ; Amler, Evžen (advisor) ; Kolářová, Hana (referee) ; Vránová, Jana (referee)
Platelet products can be used, thanks to the broad range of bioactive molecules, either as a supplement for cell cultering in vitro alone or for development of cell- or cell-free scaffolds in diverse fields in regenerative medicine. The aim of this study was to prepare several types of platelet products. The concentration of selected molecules were observed. Subsequently, these products were tested with cell cultures in vitro alone or in combination with nanofibres scaffolds prepared by electrospinning or centrifugal spinning. It was found out, that platelets products contains chemokine RANTES and growth factor PDGF in the highest concentrations. It was further discovered the content of pro and antiinflammatory in terleukins and other growth factors. Platelet lysat in concentration 7% is sufficient to replace FBS in keratinocytes and fibroblasts cultures. In the other experiments, platelets in different concentrations were adhered to the scaffolds prepared by electrospinning and centrifugal spinning. Thus prepared scaffolds promote the proliferation and viability of all tested cell types in dose-dependent manner. In the last experiment, the individual components of platelet concentrate were separated and characterized. Their effect to the cell culture were tested. It was examinated the synergic...
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Adhesion and growth of adipose tissue-derived stem cells on fibrin assemblies with attached growth factors for tissue engineering of heart valves
Filová, Elena ; Trávníčková, Martina ; Knitlová, Jarmila ; Matějka, Roman ; Kučerová, Johanka ; Riedelová, Zuzana ; Brynda, Eduard ; Bačáková, Lucie
Currently used xenogeneic biological heart valve prostheses are decellularized and crosslinked with glutaraldehyde. These grafts usually undergo degeneration and calcification. Pericardium-based heart valve prostheses, re-seeded with autologous cells, i.e. Adipose tissue-derived cells (ASCs) and endothelial cells, could have longer durability and biocompatibility. In order to improve the adhesion of cells and their ingrowth into decellularized pericardium, various fibrin (Fb) layers were developed, i.e. Fb, Fb with covalently bound heparin (H), Fb with either vascular endothelial growth factor (VEGF) or fibroblast growth factor 2 (FGF) in various concentrations (1 ng/ml, 10 ng/ml, 100 ng/ml) or with both VEGF and FGF (100 ng/ml). Growth factors were attached onto Fb via heparin or were adsorbed. ASCs were seeded on theses layers in a DMEM medium supplemented with 2 % of fetal bovine serum, TGFβ1 and BMP-4 (both 2.5 ng/ml), and with ascorbic acid. Cell adhesion and growth/viability was assessed by counted cell number/MTS evaluation. ASCs were stained for differentiation markers of smooth muscle cells, such as alpha-actin, calponin, and myosin heavy chain. On day 7, ASCs on Fb-H-VEGF layers produced both calponin and alpha-actin. An increased FGF concentration caused reduced calponin staining of ASCs. Lack of heparin in fibrin assemblies with growth factors inhibited the production of both alpha-actin and calponin in ASCs. The highest ASCs density/viability was found on Fb-H-VEGF-FGF layer. The proper formulation of fibrin coatings could be favorable for ASCs growth and differentiation and could subsequently support endothelialization of cardiovascular prostheses with endothelial cells.
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Issues of the algae Chlorella production in flow bioreactors
Jankovičová, Kristína ; Lukavský,, Jaromír (referee) ; Svěrák, Tomáš (advisor)
Microalgae invite the attention of scientists due to their unique properties, including their quick growth, accumulation of lipids and other valuable substances, fixation of carbon dioxide and treatment of wastewater. This master´s thesis is focused on the study of microalgae. The main goal is to understand and describe the process of microalgae cultivation, in order to optimize it. The theoretical part of this thesis deals with microalgae (mainly Chlorella sp.) characterization, its practical use and cultivation optimization in order to obtain the highest concentration of biomass. The experimental part is divided into three tasks. Aim of the first task was the comparison of the course of autotrophic and heterotrophic cultivation of various strains of Chlorella and Coccomyxa microalgae, using three different cultivation media – synthetic medium for chlorella cultivation and natural fertilizer, Florium, used in two different concentrations (diluted 50 and 20 times). The highest Chlorella sp. biomass concentration of 7,10 g/l was achieved in the synthetic heterotrophic medium. Second task was focused on monitoring of the growth of algae Coccomyxa and Chlorella strain C1A, with respect to temperature and light intensity, using various combinations of these two important growth factors. Chlorella achieved its highest concentration of 11,46 g/l when grown at temperature of 33,5 °C and light intensity of 320 µE.m2.s1. The third and final task was to observe the growth of Dictiosphaerium chlerelloides microalgae on a flat cascade bioreactor. The experiment led to the discovery that these algae were able to grow at temperatures of around 10 °C, at which many well-known commercial algae, such as Chlorella sp. or Arthrospina sp., simply wouldn’t grow.
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Insulin like and other growth factors and tumors
Kučera, Radek ; Topolčan, Ondřej (advisor) ; Klimeš, Jiří (referee) ; Šafarčík, Kristian (referee)
Inzulinu podobné a jiné růstové faktory a nádory Insulin like and other growth factors and tumors Disertační práce Plzeň 2011 Mgr. Radek Kučera Summary The interaction between growth factors and cancer incidence and development has been discussed recently. First works suggesting possible connection between increased production of insulin like growth factors with an increased incidence of tumors came already from early 80s of the last century. The aim of my work was focused on evaluation of possible relation between insulin like growth factors or their binding proteins and tumors from different perspectives, to assess their significance and try to determine what role the IGFs and IGFBPs may play in the current tumor diagnostics. The work itself is divided into two parts, the theoretical and practical ones. In the theoretical part, I summarized the action of IGF in human body and also focused on previous findings on the role of IGF system in cancer diagnoses. In the practical part, divided into three subsections, I focused on investigation of relations in a large set of patients with different cancer diagnoses, in a group of women with breast cancer and, finally, I focused on changes of IGF1 levels during follow-up. Theoretical part Insulin-like growth factors (IGF) are peptides, that participate on growth...
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Growth factors and other bioactive substances for osteogenic differentiation of mesenchymal stem cells
Blahnová, Veronika ; Rampichová, Michala (advisor) ; Vandrovcová, Marta (referee)
The main function of mesenchymal stem cells in the body is to facilitate the restoration and regeneration of damaged tissues. They are known for the ability to differentiate into tissue originating from the mesoderm, which among others includes connective tissues. Due to this feature are MSCs being intensively examined. Different directions of differentiation can be induced by treatment of specific polypeptides, so called growth factors. In the field of tissue engineering are growth factors used to induce and accelerate the healing processes. They may be incorporated into the nanofiber carrier which is inserted into the site of injury. Cells in this area would thus be stimulated by surrounding 3D microenvironment. At the same time the scaffold provides a supply of growth factors which are able to affect metabolism, motility and differentiation of present cells. In order to induce osteogenic differentiation of human MSCs the following bioactive substances were used: TGF-β, bFGF, HGF, IGF-1, VEGF and the BMP-2 and the organic acid taurine. During 21 days lasting experiments, were these molecules added to the medium in various combinations and in the case of taurine also at two different concentrations. Cells were cultured on plastic. The best effect on cellular metabolism of MSCs, evaluated by MTS...
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Effect of growth factors and bioactive substances on mesenchymal stem cell differentiation.
Blahnová, Veronika ; Daňková, Jana (advisor) ; Zajícová, Alena (referee)
Mesenchymal stem cells are a population of multipotent cells, which have the ability to restore damaged tissues derived from mesoderm. Under the influence of wide range of growth factors, hormones and other bioactive molecules they can differentiate for example into chondrocytes, osteocytes, adipocytes, myocytes or insulin producing cells. The differentiation is induced even by contacts with neighboring cells or with extracellular matrix. Tissue engineering often uses especially growth factors. Growth factors act through specific surface receptors, which mediate cell-to-cell and cell-to-extracelular matrix communication and influence many cellular processes such as growth, proliferation, differentiation and others. Due to their specific impact growth factors are used individually or in combinations in tissue engineering applications. Substances stimulating cells to proliferate and differentiate can be added right to the culture medium, when cultivated in vitro, or can be loaded into a scaffold onto which cells are later seeded. The determination of exact growth factors combinations and concentrations influence on MSCs differentiation would enable more efficient use of MSCs in regenerative medicine. The aim of this thesis is to summarise present knowledge about the effect of growth factors and other...
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Changes in placental angiogenesis and their impact on fetal intrauterine growth restriction
Kudějová, Alena ; Švandová, Ivana (advisor) ; Magner, Martin (referee)
Any pathological interference with normal vascular development of placenta may have a critical impact on fetal growth and development. The proliferation and differentiation of several cell types play a very important role in the vascular system of placenta. The main factors taking part in the vascular development of placenta include cell elements (e.g. trofoblast, stromal chorion cells, haemangiogenic progenitors), the extracellular matrix, growth factors and cytokines (e.g. VEGF, PlGF, Ang-1,2 and bFGF). The extrinsic factors may also influence the partial oxygen pressure, nutritients availability, and/or the blood perfusion in placenta. Placental ischaemia leading to the worsening of uteroplacentar perfusion is the most common cause of the intrauterine growth retardation (IUGR). The IUGR development is then the result of insufficient prolongation, branching, and dilatation of capillary loops during the formation of terminal villi. Published studies focusing on growth factors in placentas from physiological pregnancies and pregnancies with IUGR do not give clear results. This BSc. Thesis is a review focused on up-to-date-known data concerning changes in placental angiogenesis and their impact on IUGR. Key words: placenta, angiogenesis, IUGR, pregnancy
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Issues of the algae Chlorella production in flow bioreactors
Jankovičová, Kristína ; Kaštánek,, Petr (referee) ; Svěrák, Tomáš (advisor)
The bachelor's thesis is focused on cultivation of Chlorella microalgae species. Theoretical part deals with microalgae characteristics, their usage and methods of their cultivation. It is focused on the most important growth factors of chlorella and compares findings from earlier studies. Experimental part contains observations of microalgae growth in different environments and behavioural comparison of autotrophic and heterotrophic cultures. Next, the influence of temperature and light intensity on microalgae growth was observed, using different combinations of these factors. Experimental findings were evaluated from gained biomass concentration and absorbance determined by spectrophotometric method.
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