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Fluorescent Methods in Research of Eukaryotic Cells
Chmelíková, Larisa ; Babula, Petr (referee) ; Pešl,, Martin (referee) ; Provazník, Ivo (advisor)
Tato práce zkoumá aplikaci fluorescenčních metod používaných v in vitro studiích v oblasti regenerace srdeční tkáně. Konfokální fluorescenční mikroskopie je vhodnou mikroskopickou technikou pro výzkum v této oblasti, protože umožňuje vizualizaci 3D struktur a distribuce buněk ve 3D modelech. Používané fluorescenční markery by měly být dlouhodobě stabilní, biokompatibilní a netoxické pro živé buňky. V současné době je použití nanočástic jako superparamagnetické nanočástice oxidu železa (SPION) velmi populární; velké množství studií ukazuje, že jsou vhodné pro dlouhodobé experimenty. Tento výzkum využívá superparamagnetické maghemitové nanočástice svázaným rhodaminem na jejich povrchu (SAMN-R) a popisuje jejích excitační a emisní spektrum, velikost a lokalizaci vbuňkách. Stanovení toxicity bylo provedeno měřením reaktivních forem kyslíku (ROS) a nekvantitativním měřením pomocí fluorescenční mikroskopie bylo zjištěno, že hodnota dávky 20 µg·cm-2 je optimální pro aplikaci na živé buňky. Dále byl zkoumán vliv aplikace SAMN-R na buněčnou proliferaci a motilitu, kdy ve studii buněčné proliferace a scratch assay byla použita buněčná linie fibroblastů 3T3. Poté byla studována migrace jednotlivých buněk s použitím mezenchymálních kmenových buněk (MSCs), izolovaných zlidské tukové tkáně. Následná statistická analýza nepotvrdila, že by aplikace SAMN-R měla významný vliv na buněčnou proliferaci, kolektivní migraci nebo na migraci jednotlivých buněk. Lze tedy předpokládat, že SAMN-R jsou vhodným fluorescenčním markerem pro výzkum živých buněk, včetně experimentů voblasti regenerace tkáně. MSC buňky izolované z tukové tkáně mají velký potenciál v regeneraci srdeční tkáně. Jejich interakce s buněčnou linií srdečních svalových buněk HL-1 byly studovány pomocí scratch assay, kdy se tento model jeví jako nadějný a vhodný pro studium buněčných kontaktů a jejich roli přiregeneraci buněk.
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Immunomodulatory properties of mesenchymal stem cells - use in therapy
Pavlíková, Michaela ; Krulová, Magdaléna (advisor) ; Stříž, Ilja (referee)
Mesenchymal stem cells (MSC) are extensively studied mainly due to their feasible clinical application. Therapeutic potential of MSC consists not only of the ability to differentiate into mesenchymal cells, ectodermal and endodermal cell lines, but primarily in their immunomodulatory functions. Due to their effect on immune cells, MSC promote the shift of the inflammatory immune response to antiinflammatory. The ability to suppress inflammation, together with their differentiation potential and antiapoptotic potential on the surrounding cells makes MSC a promising tool for treating serious diseases. This work discusses the effect of MSC on the individual cells of the immune system. It focuses on the description of the effect of MSC in four model cases. These are an experimental autoimmune encephalomyelitis, myocardial infarction, diabetes mellitus and skin graft transplantation. The knowledge of the mechanisms of the interactions between MSC and the cells of the immune system, together with the understanding the effect of specific conditions on MSC is essential for their use in clinical therapy. Keywords: mesenchymal stem cells, immunomodulation, autoimmune diseases, transplantation
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Immunomodulatory and regenerative potential of mesenchymal stem cells in the treatment of degenerative retinal disorders in mice
Palacká, Kateřina ; Heřmánková, Barbora (advisor) ; Grobárová, Valéria (referee)
Retinal degenerative disease are the leading cause of vision loss in adult patients. Important role in the development of these types of disease play gradual death of retinal cells and an inflammatory reaction that leads to the production of cytokines, formation of inflamasome, increased angiogenesis and scar formation. These pathologies result in irreversible degeneration of retinal cells. Retinal pigmenetd epithelium cells, photoreceptors and ganglion cells are the most frequently damaged cell types in this conditions. The available treatments are currently very limited and effective only at the early stages of the disease. Therefore, the use of stem cell- based therapy could be a promising option. For therapeutic purposes it would be possible to use mesenchymal stem cells (MSCs) which may be isolated for example from bone marrow or adipose tissue. MSCs are capable of production of neuroprotective factors, differentiation into the variety of cells types and regulation of immune response. In this study we tested the therapeutic potential of MSC administered locally to the damaged retina in an experimental model of retinal degeneration. We focused on the protective effect of MSCs on photoreceptor cells, regulation of the local immune response and expression of genes for cytokines involved in...
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Study of the effect of mesenchymal stem cells in combination with immunosuppressive therapy on inflammatory response in in vivo model
Jabůrek, Filip ; Krulová, Magdaléna (advisor) ; Brdička, Tomáš (referee)
Immunosuppressive drugs have been used for many years for the treatment of autoimmune diseases and post-transplantation treatment. While these drugs have a lot of advantages, they also show several undesirable side effects. The most common side effects are higher blood pressure, lowered renal function and susceptibility to infections. Therefore, in recent years there has been a demand for other medical approaches that do not exhibit the above-mentioned adverse effects. Among one of the newly tested approaches is the application of mesenchymal stem cells (MSCs), which possess several advantages such as immunomodulatory abilities, safety and relatively easy isolation, however, stem cell use alone has not yet provided sufficiently strong immunomodulation. Only a small part of research of MSCs is focused on their use in the combination with immunosuppressive therapy. Therefore, in my thesis I focused on the model which allows to reduce the dose of immunosuppressive drugs in the combination with MSCs. Combined therapy is more advantageous than both monotherapies thanks to lower dosages of these drugs used. It enables to decrease negative side effects of immunosuppressive drugs, when combined with MSCs to provide sufficient immunomodulation in comparison to classical therapy. The aim of my work was to...
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Mesenchymal stem cells and the possibility of their transdifferentiation into insulin producing cells.
Dostálová, Veronika ; Holáň, Vladimír (advisor) ; Čečrdlová, Eva (referee)
Mesenchymal stem cells (MSCs) have been demonstrated in almost all tissues of the body. Their main source is bone marrow and adipose tissue. These cells are multipotent, e.g. they are capable of differentiating into a variety of cell types. They are able to migrate into damaged tissues. Their other relevant property is a specific suppression of imunity. In the body they serve as precursors for specialized cell types and they also participate in formation of specific tissue microenvironment. Their properties represent a great potential in a wide range of clinical therapies. Besides other possible applications they could be used in the therapy of diabetes mellitus type one. During this disease insulin producing -cells are destroyed. MSCs have been used in experimental in vitro and in vivo studies to differentiate into insulin producing cells. However these cells are not able to produce sufficient amounts of insulin to exclude the supportive administration of exogenous insulin. Therefore there is a need for further research in this field of possible therapy.
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Characterization of functionalized fibres for mesenchymal stem cells cultivation and differentiation
Greplová, Jarmila ; Amler, Evžen (advisor) ; Rosina, Jozef (referee)
Modification of nanofibers is an actual trend in tissue engineering. Polyvinylacohol (PVA) is nontoxic and biodegradable polymer suitable for preparation of submicron fibers by electrospinning. Main disadvantage of PVA fibers is rapid degradation in aqueous environment. On the other hand surface of fibers contains free hydroxyl group that could be chemically modified. In recent work, chemical modification of PVA nanofibers prepared by needleless electrospinning was investigated. Polyethylenglykol (PEG) linker was introduced to the fiber surface by acylation (PVA-PEG) and further modified by biotin (PVA-PEG-b) as a function agent. Process of chemical modification does not affected fibrous morphology of samples. Interestingly, linkage of PEG-b linker promoted stability of PVA in aqueous environment. PVA-PEG-b sample was stable for 41 days. Stability of samples was strongly dependent on amount of introduced PEG-b linker, thus proposed method of modification allows to prepare nanofibers of different solubility. Additionally, biocompatibility of chemically modified nanofibers with both mesenchymal stem cells (MSC) and chondrocytes was determined. Proliferation of both cell types was not sufficient and number of cells decreased in time, probably because of high hydrophility of modified PVA scaffold. To...
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The therapeutic potential of mesenchymal stem cells in a mouse experimental model
Hájková, Michaela ; Krulová, Magdaléna (advisor) ; Hrdý, Jiří (referee) ; Šírová, Milada (referee)
Due to their immunomodulatory and regenerative potential, mesenchymal stem cells (MSCs) represent a promising therapeutic tool for cell-based therapy, organ transplantation or tissue engineering. To improve clinical applicability of MSCs, new methods to increase their delivery and efficacy have been tested in the latest years but the mechanism of observed alterations has not yet been described. In the present project we focused on studying the effect of several factors that can significantly affect the therapeutic success of MSC-based treatment. Initially, we analysed the therapeutic effect of MSCs applied locally on nanofiber scaffold with incorporated cyclosporine A (CsA) in a mouse model of allogeneic skin transplantation. Our results indicate that application of MSCs in the presence of CsA direct M1/M2 macrophage polarization towards regulatory phenotype. This phenotype switching is accompanied by decreased production of nitric oxide (NO) and interferon (IFN-) and increase production of interleukin 10 (IL-10), and may result in suppression of the local inflammatory reaction. The next goal of proposed study was to analyse the effect of the treatment based on MSCs combined with immunosuppressive drugs with different mechanism of action on the balance among distinct T cell subpopulations. We...
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Immunomodulatory mechanisms of stem cells and their use for therapy of ocular disorders
Heřmánková, Barbora ; Holáň, Vladimír (advisor) ; Heissigerová, Jarmila (referee) ; Indrová, Marie (referee)
Stem cell-based therapy represents a perspective approach for the treatment of many so far incurable diseases. Mesenchymal stem cells (MSC) are currently the most studied stem cells. They are able to differentiate into different cell types, to produce growth and trophic factors and can suppress the functions of cells of the immune system. During the study of the immunomodulatory properties of MSC, we focused on their effect on B cells. The mechanism of impact of interferon-γ (IFN-γ) on MSC and their effect on the production of interleukin 10 (IL-10) by B cells was analysed. We have demonstrated that MSC-treated with IFN-γ inhibit production of IL-10 by activated B cells via the cyclooxygenase-2 involving pathway. Due to their regenerative and immunomodulatory properties, MSC can be for treatment of many diseases. In this study we focused on the disease and damage of the eye. The limbal stem cells (LSC) are used for the treatment of damaged ocular surface, however their isolation is difficult and they can not be used in all cases of damage. Appropriate candidates in these cases are MSC. Therefore we have decided to compare the therapeutic potential of LSC and MSC isolated from bone marrow or adipose tissue. The study have shown that MSC isolated from bone marrow have a similar regenerative effect on...
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The use of immunoregulatory properties of mesenchymal stem cells/ and their therapeutic potential
Javorková, Eliška
Mesenchymal stem cells (MSCs) have the potential to differentiate into various cell types, possess potent immunomodulatory properties and can influence various functions of immune cells. Since the immunomodulatory properties of MSCs can be modified by cytokines, we compered the effect of unstimulated MSCs and MSCs pretreated with interleukin (IL)-1, interferon (IFN)- , transforming growth factor (TGF)- and IL-10 on the development of regulatory T cells (Treg) and T helper 17 (Th17) cells in vitro and on the inflammatory environment in the eye. MSCs can produce significant levels of TGF- and IL-6. These cytokines represent the key factors that reciprocally regulate the development of naive T cells into Treg and Th17 cells. Unstimulated MSCs produce TGF- , but not IL-6, and the production of TGF- can be further enhanced by IL-10 or TGF- . In the presence of IL-1, MSCs secrete significant levels of IL-6, in addition to spontaneous production of TGF- . MSC producing TGF- induced preferentially expression of Foxp3 and activation of Treg lymphocytes, whereas MSCs supernatants containing TGF- together with IL-6 supported ROR t expression and development of Th17 cells. We demonstrated that MSCs and their products effectively control the development of Tregs and Th17 cells in a population of...
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Use of biological materials for tissue substitution in plastic surgery
Měšťák, Ondřej ; Sukop, Andrej (advisor) ; Brychta, Pavel (referee) ; Dražan, Luboš (referee)
Užití biologických materiálů k náhradě tkání v plastické chirurgii ! Abstrakt v angličtině Background: Biological meshes are biomaterials consisted of extracellular matrix and used in surgery particularly for hernia treatment or thoracic wall reconstruction. They are capable of vascularization, that decreases risk of infection, expecially when used in contaminated fields. This study compared the strength of incorporation and biocompatibility of two porcine-derived grafts (cross-linked and non-cross-linked) in a rat hernia model. In addition, we hypothesized that combination of extracellular matrices with autologous mesenchymal stem cells used for hernia repair would result in increased vascularization and increased strength of incorporation. Methods: Standardized 2 x 4 cm fascial defect was created in 42 Wistar rats and repaired with a cross-linked or a non-cross-linked graft either enriched or non-enriched with stem cells. The rats were sacrificed 3, 6 and 12 months later. The strength of incorporation, vascularization, cellular invasion, foreign body reaction and capsule formation were evaluated. Results: Comparison of stem cell enriched and non-enriched groups showed no significant differences in the capsule thickness, foreign body reaction, cellularization or vascularization. In the non-cross-linked...
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