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Transforming growth factor-ß (TGF-ß) reguliert eine Vielzahl zellulärer Funktionen, wie Proliferation, Differenzierung und Apoptose. Über membrangebundene Serin/Threonin-Kinase-Rezeptoren werden TGF-ß Signale durch Phosphorylierung an Smad-Proteine, die intrazellulären Signaltransduktoren, weitergeleitet, die im Kern die Transkription spezifischer Gene modulieren. Obwohl die drei TGF-ß Isoformen, TGF-ß1, -ß2 und -ß3, äußerst homologe Proteine sind, unterscheiden sich die Phänotypen ihrer Genknockouts stark. Variabilität und Spezifität können auf vielerlei Arten und Ebenen der TGF-ß Signalübertragung erreicht werden. In der vorliegenden Arbeit wird eine alternativ gespleißte Variante des TGF-ß Typ II Rezeptors (TßRII), TßRII-B, charakterisiert. Dieser Rezeptor ist, im Gegensatz zum bisher bekannten TßRII, in der Lage alle drei TGF-ß Isoformen hochaffin zu binden und in Abwesenheit eines unterstützenden Typ III Rezeptors (TßRIII) Signale über den Smad-Pathway weiterzuleiten. TßRII-B ist außerdem fähig ligandenabhängig mit den verschiedenen TGF-ß Rezeptortypen zu Oligomerisieren. Erste Hinweise auf Besonderheiten der TGF-ß2 Bindung an TßRII-B wurden mittels verschiedener zellbiologischer Ansätzen gewonnen. Aus Untersuchungen zur gewebespezifischen Expression des Rezeptors geht hervor, daß TßRII-B, im Vergleich zu TßRII, ein distinktes Expressionsmuster aufweist und v.a. in TGF-ß2-beeinflußten Geweben nachgewiesen werden kann. In diesen Erkenntnissen spiegelt sich die Bedeutung dieses Rezeptors für eine TGF-ß Isoform-spezifische Signalübertragung wider. Der zweite Teil der vorliegenden Arbeit beschäftigt sich mit der Rolle von TGF-ß und seinen Rezeptoren bei der Entstehung von Tumoren. B-Zellen einiger Patienten mit chronischer lymphatischer Leukämie (B-CLL), der häufigsten Form adulter Leukämie in westlichen Ländern, zeigen Resistenz gegenüber TGF-ß-vermittelter Wachstumsinhibierung und ein verändertes Expressionsmuster der TGF-ß Rezeptoren an ihrer Zelloberfläche. In dieser Arbeit wird die Identifizierung und Charakterisierung zweier Mutationen innerhalb der putativen Signalpeptidsequenz des TGF-ß Typ I Rezeptors (TßRI) in B-Zellen TGF-ß resistenter CLL-Patienten beschrieben. Hierbei handelt es sich um einen Aminosäure-Austausch (L12Q) und eine ‚in-frame‘ Alanin-Deletion (A8) innerhalb einer aus 9 Alaninen bestehenden Sequenz. Es konnte gezeigt werden, daß diese Mutationen zwar keinen Einfluß auf Oberflächenexpression und Komplexbildungseigenschaften des TßRI haben, jedoch TGF-ß stimulierte Reportergeninduktion verringern, was eine kausale Beziehung bei der Entwicklung TGF-ß resistenter B-CLL-Zellen vermuten läßt. Ein Auftreten von Mutationen innerhalb der 9-Alanin-Sequenz des TßRI korreliert mit TGF-ß Insensitivität von B-CLL Zellen. Obwohl noch weitere Studien benötigt werden, um den präzisen molekularen Mechanismus zu verstehen, der zu TGF-ß Resistenz in B-CLL Zellen führt, kann spekuliert werden, daß TßRI Mutationen das Voranschreiten von B-CLL und evtl. anderen Tumorarten unterstützen. Gezieltes Screenen nach TßRI Signalpeptidsequenz Mutationen könnte demnach als prognostischer Indikator für Tumorprogression eingesetzt werden. / Transforming growth factor-ß (TGF-ß) regulates a variety of cellular functions like proliferation, differentiation and apoptosis. It signals through membrane-bound serine/threonine kinase receptors, which upon stimulation phosphorylate Smad proteins, the intracellular signaltransducers, and thereby trigger their nuclear translocation and transcriptional activity. Although the three mammalian TGF-ß isoforms, TGF-ß1, -ß2 and –ß3, are highly homologous proteins, the phenotypes of their genknockouts reveal striking differences. Variability and specificity can be achieved on different levels of the TGF-ß signaltransduction. In this work an alternatively spliced variant of the TGF-ß type II receptor (TßRII), TßRII-B, is characterized, which in contrast to TßRII binds and mediates signaling of all TGF-ß isoforms. This signaling occurs via the Smad pathway and is independent of any supporting type III receptor (TßRIII). Therefore interaction and oligomerization of TßRII-B with the TGF-ß isoforms as well as the different TGF-ß receptor types was analyzed in detail. Furthermore we defined the characteristics of TGF-ß2 binding to TßRII-B. Expression studies demonstrate that TßRII-B expression is restricted to cells originating from tissues where the TGF-ß2 isoform has a predominant role. All that reflects the importance of this receptor splice-variant in TGF-ß isoform-specific signaling. The second part of this work focuses on the role of TGF-ß and its receptors in tumor development. B cell chronic lymphocytic leukemia (B-CLL) is the most common lymphoid cancer in Western societies, and is also currently incurable. B-cells from some B-CLL patients are resistant to the growth inhibitory effects of TGF-ß and show a different expression pattern of TGF-ß receptors at their cell surface. In this work the identification and characterization of two mutations within the putative signal sequence of the tßrI gene in B-cells from TGF-ß resistant B-CLL patients is described. Thereby a single aminoacid substitution (L12Q) is accompanied by an ‘in frame’ single alanine deletion within an 9-alanine stretch. It could be shown that this mutations do not mediate the apparent loss of functional TßRI in TGF-ß resistant B-CLL, but they attenuate reporter gene induction stimulated by TGF-ß, suggesting a causal relationship in the development of TGF-ß resistant B-CLL. The appearance of mutations within the 9-alanine stretch of the TßRI correlated with and predicted for B-CLL patient insensitivity to TGF-ß. Although more studies are needed to ascertain the precise molecular mechanism leading to TGF-ß resistance in B-CLL cells, it is tempting to speculate that these TßRI mutations may promote the progression of B-CLL and other cancers from their indolent to active states. This suggests that screening for TßRI signal sequence mutations can be employed as a prognostic indicator of B-CLL patient sensitivity to TGF-ß.

Das Zytokin Bone Morphogenetic Protein-2 (BMP-2) gehört als Mitglied der Transforming Growth Factor ß-Superfamilie zu einer großen Gruppe eng verwandter Wachstums- und Differenzierungsfaktoren. Es spielt eine entscheidende Rolle bei Bildung und Regeneration von Knorpel und Knochen und während verschiedener Prozesse der embryonalen Entwicklung. Durch Sezernierung des Proteins und anschließende Diffusion in der extrazellulären Matrix (EZM) ausgehend vom Ort der Sekretion unterliegt sein Wirkungsgrad einem abnehmenden Konzentrationsgradienten. BMP-2 bindet neben der hochaffinen Bindung an seinen spezifischen Rezeptor unter anderem auch an die extrazelluläre Matrix. So konnte in Vorarbeiten bereits durch Deletion der basischen Heparinbindungsstelle des BMP-2, die sich im N-terminalen Bereich befindet, eine Wirkungsverstärkung des Proteins in einem in vitro- Experiment, dem Hühnergliedmaßentest, erreicht werden, da die konkurrierende Bindung an Heparinbindungsstellen der EZM wegfällt. Im Tiermodell konnte jedoch ein genau umgekehrter Effekt dieser Mutante im Vergleich mit dem Wildtyp gezeigt werden, da in vivo die Diffusion des Moleküls durch Bindung an die EZM begrenzt und es so lokal an seinem Wirkungsort konzentriert wird. Von diesen Vorbefunden ausgehend war das Ziel der Arbeit die Klonierung und Expression von Mutanten des BMP-2, bei denen durch schrittweise Modifizierung der Heparinbindungsstelle die Bindung des Proteins an Heparin und deren Einfluß auf die Rezeptorbindung charakterisiert werden sollte. Dazu wurden zwei Mutanten des BMP-2 mit Verdopplung eines bzw. beider basischer Aminosäuretripletts kloniert, da diesem basischen Bereich im N-Terminus die eigentliche Bindung an Heparin zugeschrieben wird. Nach Expression, Renaturierung und säulenchromatographischer Aufreinigung der Proteine konnte in dieser Arbeit in drei verschiedenen funktionellen in vitro-Tests eine abnehmende Wirkung der Mutanten gezeigt werden. Neben dem biophysikalischen Nachweis der apparenten Affinitäten der Mutanten zu Rezeptor und Matrix in Biacore-Messungen konnte die Änderung des Wirkungsgrades auch in einem Zellkulturassay mit einer Maus-Fibroblasten-Zellinie durch Messung der Alkalischen Phosphatase und im Hühnergliedmaßentest gezeigt werden. In in vivo Experimenten bleibt eine entsprechende zu erwartende Wirkungsverstärkung dieser beiden Mutanten nachzuweisen, die im Hinblick auf einen therapeutischen Einsatz bei gewünschtem Ersatz zerstörten Knochens relevant werden könnte. / Bone morphogenetic protein-2 is a cytokine belonging to the TGFß-superfamily. We performed a modification of its heparin binding site in order to investigate a possible correlation between the basic acids of the heparin binding site and the function of the protein in vitro.

A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, 2014. / Alzheimer’s Disease (AD) is characterized by neurofibrillary tangles, senile plaques and neuronal loss. Although the mechanisms underlying Amyloid beta 42 (Aβ42) neurotoxicity have not been firmly established, it is proposed that the neuronal loss is elicited through associations with cell surface receptors. The cellular prion protein (PrPc) has been identified as an Aβ42 receptor and as a regulator of the amyloidogenic cleavage pathway. As Aβ42 shares common binding partners with the 37kDa/67kDa laminin receptor (LRP/LR), including PrPc, we investigated whether these proteins interact and assessed the pathological significance of this association. LRP/LR was found to co-localize with Aβ on the cell surface. The occurrence of FRET suggested that an interaction between LRP/LR and Aβ indeed exists at the cell surface. Furthermore, pull down assays and Aβ-specific ELISAs demonstrated that LRP/LR forms a physical association with endogenously shed Aβ, thereby verifying the physiological relevance of this association. Antibody blockade by IgG1-iS18 and shRNAmediated downregulation of LRP/LR significantly enhanced cell viability and proliferation and decreased apoptosis in cells co-treated with Aβ42 when compared to cells incubated with Aβ42 alone. In addition, antibody blockade and shRNA-mediated downregulation of LRP/LR significantly impeded Aβ42 internalization. These results suggest that LRP/LR acts as an internalization receptor for Aβ42 and may thereby contribute to the cytotoxicity of the neuropeptide by facilitating intracellular Aβ42 accumulation and aggregation - which has consequences for cell proliferation and may promote apoptosis. These findings recommend anti-LRP/LR specific antibodies and shRNAs as potential therapeutic tools for Alzheimer’s Disease treatment.

Thesis (M.Com. (Finance))--University of the Witwatersrand, Faculty of Commerce, Law and Management, School of Economic and Business Sciences, 2016 / This study aims to investigate the presence of the low market risk (beta) anomaly in the Johannesburg Stock Market (JSE). Finance theory suggests that with higher return comes higher risk. However, several studies have reported evidence of low risk anomaly in global markets where portfolios containing low beta shares delivers superior risk adjusted returns compared to market index and high beta shares' portfolio. This study will explore various risk return relationships on the JSE and test a variety of potential explanations of the anomalous behaviour of the low beta premium. Three explanations have been identified as potential factors that contribute to the persistence of the Low Beta Anomaly. These include; Net International Equity flows (NIEF), Idiosyncratic Risk and Market Concentration. The results are consistent with international literature indicating a persistent Low Beta Anomaly on the JSE. However, the results also indicate that in periods of turmoil, high beta shares outperform low beta shares i.e. during the Global Financial Crisis. Although some significant relationships are found between the low minus high beta differential and NIEF. NIEF is unable to suitably explain the anomaly. Idiosyncratic risk results are mixed depending on the model used to calculate the idiosyncratic risk estimates. Despite being a significant issue on the JSE, Market concentration does not explain the Low Beta Anomaly. As the superior performance of the low beta portfolios remains once the portfolios returns have been adjusted for the different variables however magnitude ofthe outperformance ofthe low beta portfolio was to a lesser degree. / AC2016

Mutations in HNF1A cause Maturity Onset Diabetes of the Young type 3, the second most frequent form of diabetes caused by single gene mutation. We generated human stem cell-derived pancreatic endocrine cells with clinically pathogenic mutations in HNF1A and show that HNF1A deficiency impairs endocrine cell fate, insulin granule maturation and the secretion of insulin in response to glucose. Single-cell RNA sequencing reveals that HNF1A orchestrates a network of genes involved in β-cell fate, granule maturation, glucose metabolism, calcium ion binding and hormone exocytosis. In both patients and stem cell-derived β-cells, HNF1A deficiency altered the stoichiometry of secreted insulin to c-peptide. Sulfonylurea, used in the treatment of these patients, restored both insulin secretion and stoichiometry. The uncoupling of insulin and c-peptide secretion as described here questions the common practice of using c-peptide as a proxy to evaluate β-cell function. We also demonstrate that correction of the HNF1A mutations restores function, providing a path to cell-based replacement therapy.

Alzheimer’s disease (AD) has been defined as a type of dementia that causes problems with memory, thinking, and behavior. AD is characterized by tau tangles and Aβ plaques in and around neurons, respectively. The impact this disease has on its victims’ health, both physically and mentally, is unimaginable and the rate of progression is not expected to decrease any time soon. This threat to our minds encourages the importance of understanding AD. Amongst the theories as to what bio mechanisms cause the brain to intertwine is the amyloid cascade hypothesis. The purpose of this thesis is to review the amyloid cascade hypothesis and discuss treatments which utilize this model. We also wish to examine social aspects such as loneliness and socioeconomic factors which are associated with the progression of AD. Research presented provides evidence that targeting the accumulation of Aβ in the brain will prevent further biochemical responses to form neurodegenerative pathology. From the collected data, we observe that therapies targeting the amyloidogenic pathway have received positive feedback in the medical community. Amongst them, an Aβ synthetic peptide vaccine which made history in vaccine development due to their responder rate. The impact of social factors such as loneliness in the advancement of AD is also supported by research. While it is acknowledged that any neurodegenerative disease is far too complex to narrow its cause specifically, this thesis provides an association with multiple aspects that can be understood and applied to future research in this field. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection

Pui Lan Wong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1993. / Includes bibliographical references (Leaves 109-122). / Abstract --- p.i / Acknowledgements --- p.iii / Chapter Chapter1 --- Introduction / Chapter 1.1 --- A general introduction on mast cells --- p.1 / Chapter 1.2 --- Activation of mast cells --- p.6 / Chapter 1.3 --- Mediators of mast cells --- p.18 / Chapter 1.4 --- Usage of β-adrenoceptor agonists in asthma therapy --- p.26 / Chapter 1.5 --- Aim of this study --- p.32 / Chapter Chapter2 --- Materials and methods / Chapter 2.1 --- Chemicals --- p.42 / Chapter 2.2 --- Buffers and stock solutions --- p.43 / Chapter 2.3 --- Source of mast cells --- p.45 / Chapter 2.4 --- Animal sensitization --- p.45 / Chapter 2.5 --- Isolation of mast cells --- p.46 / Chapter 2.6 --- Procedure for the investigation of the effects of adrenoceptor agonists on histamine release from mast cells --- p.48 / Chapter 2.7 --- Procedure for the investigation of propranolol antagonism --- p.49 / Chapter 2.8 --- Histamine assay --- p.50 / Chapter 2.9 --- Data analysis --- p.50 / Chapter Chapter3 --- Results / Chapter 3.1 --- Establishment of experimental conditions --- p.53 / Chapter 3.2 --- The effects of β-agonists on immunologically induced histamine release from guinea pig lung mast cells --- p.54 / Chapter 3.3 --- The effects of β-agonists and two anti-allergic drugs on immunologically induced histamine release from guinea pig lung mast cells --- p.56 / Chapter 3.4 --- The effects of β2-agonists on histamine release induced by non-immunological agents from guinea pig lung mast cells --- p.56 / Chapter 3.5 --- Antagonism by propranolol on the effects of β2-agonists on histamine release from guinea pig lung mast cells --- p.57 / Chapter 3.6 --- The effects of β2-agonists on immunologically induced histamine release from rat peritoneal mast cells --- p.58 / Chapter 3.7 --- The effects of β2-agonists on immunologically induced histamine release from human lung mast cells --- p.58 / Chapter 3.8 --- "Comparison of the effects of β2-agonists on immunologically induced histamine release from mast cells isolated from the rat peritoneum, the guinea pig lung and the human lung" --- p.59 / Chapter Chapter4 --- Discussion / Chapter 4.1 --- The effects of β-agonists on immunologically induced histamine release from guinea pig lung mast cells --- p.89 / Chapter 4.2 --- The effects of β2-agonists and two anti-allergic drugs on immunologically induced histamine release from guinea pig lung mast cells --- p.97 / Chapter 4.3 --- The effects of novel β2-agonists on histamine release induced by non-immunological agents from guinea pig lung mast cells --- p.99 / Chapter 4.4 --- The study of propranolol --- p.100 / Chapter 4.5 --- The heterogeneity of mast cells --- p.103 / Chapter Chapter5 --- General conclusion --- p.107 / References --- p.109

Kai Hong Kwok. / Thesis submitted in: December 1997. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 90-98). / Abstract also in Chinese. / Chapter Chapter 1 --- Introduction / Chapter 1.1. --- Classification of β-adrenoceptor in cardiovascular system --- p.1 / Chapter 1.2. --- Vasodilator effects of β-adrenoceptor-agonists and their mechanisms --- p.4 / Chapter 1.3. --- Role of endothelium in β-adrenoceptor-mediated vasodilation --- p.7 / Chapter 1.4. --- Role of K+ channels in β-adrenoceptor-mediated relaxation --- p.11 / Chapter 1.5. --- Other aspect regarding the vascular response to stimulation of B-adrenoceptor --- p.15 / Chapter 1.6. --- Clinical aspect of B-adrenoceptor agents --- p.15 / Chapter Chapter 2 --- Methods and Materials / Chapter 2.1. --- Tissue Preparation --- p.19 / Chapter 2.1.1. --- Preparation of the isolated rat mesenteric artery --- p.19 / Chapter 2.1.2. --- Removal of the functional endothelium --- p.19 / Chapter 2.1.3. --- Organ bath set-up --- p.20 / Chapter 2.1.4. --- Length-tension relationship and an optimal resting tension --- p.22 / Chapter 2.2. --- Experimental Procedure --- p.22 / Chapter 2.2.1. --- Relaxant effects of the B-adrenoceptor agonists --- p.24 / Chapter 2.2.2. --- Effects of putative K+ channel blockers --- p.24 / Chapter 2.2.3. --- Effects of inhibitors of nitric oxide activity --- p.25 / Chapter 2.2.4. --- Effect of indomethacin --- p.25 / Chapter 2.2.5. --- "Effects of K+ channel opener, nitric oxide donor and forskolin" --- p.26 / Chapter 2.3. --- Chemicals and Solutions --- p.26 / Chapter 2.3.1. --- Chemicals and drugs --- p.26 / Chapter 2.3.2. --- Preparation of drug stock solutions --- p.26 / Chapter 2.3.3. --- Solutions --- p.28 / Chapter 2.4. --- Statistical Analysis --- p.28 / Chapter Chapter 3 --- Results / Chapter 3.1. --- Relaxant Effect of Isoprenaline --- p.29 / Chapter 3.1.1. --- Relaxant effect of isoprenaline --- p.29 / Chapter 3.1.2. --- Effects of inhibitors of nitric oxide activity --- p.29 / Chapter 3.1.3. --- Effect of charybdotoxin on the vasorelaxant response to isoprenaline --- p.32 / Chapter 3.1.4. --- Effect of glibenclamide on the vasorelaxant response to isoprenaline --- p.32 / Chapter 3.1.5. --- Effect of TPA+ on isoprenaline-induced relaxation --- p.36 / Chapter 3.1.6. --- Effect of TPA+ in the presence of iberiotoxin or glibenclamide --- p.36 / Chapter 3.1.7. --- Effect of Ba2+ on the vasorelaxant effect of isoprenaline --- p.41 / Chapter 3.1.8. --- Effect of raising extracellular K+ on isoprenaline-mediated relaxation --- p.41 / Chapter 3.2. --- Relaxant Effect of Dobutamine --- p.44 / Chapter 3.2.1. --- Effects of inhibitors of endothelium-derived factors on the relaxant effect of dobutamine --- p.44 / Chapter 3.2.2. --- Antagonism of the effect of dobutamine by β1-adrenoceptor antagonist --- p.44 / Chapter 3.2.3. --- Effects of putative Kca channel blockers on the relaxant effect of dobutamine --- p.51 / Chapter 3.2.4. --- Effect of TPA+ on the relaxant effect of dobutamine --- p.55 / Chapter 3.2.5. --- Effect of raising extracellular K+ on the relaxant effect of dobutamine --- p.55 / Chapter 3.3. --- Relaxant Effect of Fenoterol --- p.57 / Chapter 3.3.1. --- Effect of inhibitors of nitric oxide activity on the relaxant effect of fenoterol --- p.57 / Chapter 3.3.2. --- Effect of charybdotoxin on the relaxant effect of fenoterol --- p.57 / Chapter 3.3.3. --- Effect of TPA+ on the relaxant effect of fenoterol --- p.64 / Chapter 3.3.4. --- Effect of glibenclamide on the relaxant effect of fenoterol --- p.64 / Chapter 3.3.5. --- Effect of raising extracellular K+ on fenoterol-mediated relaxation --- p.64 / Chapter 3.4. --- Effects of cAMP- and cGMP-elevating agents --- p.69 / Chapter 3.4.1. --- Effects of inhibitors of endothelium-derived factors on the relaxation induced by nitroprusside and forskolin --- p.69 / Chapter 3.4.2 --- Effect of charybdotoxin on relaxant effect of forskolin --- p.69 / Chapter 3.4.3 --- Effect of Ba2+ on the vasorelaxant effect of forskolin --- p.76 / Chapter 3.4.4 --- Effect of TPA+ on the relaxant effect of forskolin --- p.76 / Chapter 3.4.5 --- Effect of glibenclamide on the relaxant effects of forskolin and cromakalim --- p.76 / Chapter Chapter 4 --- Discussion / Chapter 4.1. --- Effect of Isoprenaline and Fenoterol --- p.77 / Chapter 4.2. --- Effect of Dobutamine --- p.83 / Chapter 4.3. --- Conclusion --- p.88 / References --- p.90 / Publications --- p.98

In this thesis, I present the theory of neutrinoless double-beta decay (0 2 ), particularly the theory of exotic modes of 0 2 involving the emission of one or two Majorons. Alongside this, I summarise the most recent results in the experimental search for 0 2 , including limits on the rate of these exotic processes. I describe the SNO+ experiment and it's physics goals, which include the search for 0 2 . As part of the SNO+ collaboration, I have made a signi cant contribution towards the development of the data quality software that is essential for ensuring SNO+ can achieve its physics goals-including in 0 2 searches. I describe how I developed a software package that performs the high-level data quality checks. Continuing with the software theme, I then describe a python-based limit-setting and tting software package called echidna. I have been a lead developer of echidna as part of my PhD, so I describe the software in detail and how it can be used to set limits on 0 2 signals. By reproducing the sensitivity results of the KamLAND-Zen experiment, in four key Majoronemitting 0 2 modes, I verify the use of echidna as a limit-setting tool for this type of search. Finally, I present the results of a comprehensive sensitivity study, where I determine the potential sensitivity of SNO+ to the same set of Majoron-emitting modes that KamLAND-Zen and other 0 2 experiments have already investigated.