CD97 gehört zur Familie der Adhäsions-G-Protein gekoppelten Rezeptoren (aGPCR), die aus einem langen extrazellulären N-terminalen Fragment (NTF) und einem nicht-kovalent gekoppelten C-terminalen Fragment (CTF) mit der sieben-transmembranären (TM7) Region und dem intrazellulären Teil bestehen. CD97 wird in malignen Tumoren exprimiert. In der humanen Fibrosarkomzelllinie HT1080 steigert die stabile Überexpression von CD97 die ungerichtete zweidimensionale (2D) Migration einzelner Zellen. Eine Verkürzung von CD97 im CTF auf zwei transmembranäre (TM2) Domänen führt zu einer Suppression der 2D-Migration im Vergleich zu stabil mock-transfektierten HT1080 Kontrollzellen. Wahrscheinlich supprimiert CD97/TM2 die endogene CD97-Wirkung. Unbekannt ist, welche Signalwege durch CD97-Überexpression in HT1080 reguliert werden und welche Signalwege für die Migrationssteigerung von HT1080 verantwortlich sind. Die Klärung dieser Signalwege ist Gegenstand der vorliegenden Arbeit. Die Phosphorylierung von Proteinkinasen ist eine posttranslationale Modifikation zur Regulation der Kinaseaktivität mit nachfolgender Aktivierung oder Inaktivierung eines Signalweges. Daher sind Expression und Phosphorylierung der Proteinkinasen zur Identifikation regulierter Signalwege interessant. Dazu wurden in Lysaten von CD97/TM7, CD97/TM2 und mock-transfektierten HT1080 mittels Kinetworks Phosphosite Screen KPSS 1.3 Profiling (Multi-Immunoblot™) 37 verschiedene Proteinphosphorylierungen untersucht und regulierte Signalwege identifiziert. An 25 Phosphorylierungsstellen erfolgt eine Regulation durch CD97. Anschließend wurden die Ergebnisse der interessantesten Proteine hinsichtlich ihrer Expression und Phosphorylierung im Western Blot verifiziert und um Proteine erweitert, die klassisch an der Regulation der Zellmigration beteiligt sind. Es zeigt sich eine Aktivierung des PI3-Kinase/Akt-Signalweges und eine Inhibierung von Src durch CD97. 2D-Migrationsversuche von HT1080 CD97/TM7, CD97/TM2 und mock mit spezifischen Inhibitoren gegen den PI3-Kinase/Akt-Signalweg und gegen Src bestätigen, dass diese Kinasen an der CD97-induzierten Steigerung der 2D-Migration beteiligt sind. Weiterhin finden sich Hinweise, dass in HT1080 CD97 die Apoptose hemmt und die Proliferation reguliert. Insgesamt wird in dieser Arbeit ein Überblick über die durch CD97 regulierten Signalwege gegeben. Die CD97-gesteigerte 2D-Migration von HT1080 wird durch eine Aktivierung des PI3-Kinase/ Akt-Signalweges und Inhibierung von Src vermittelt.

Signals convey information to marketplace participants regarding the unobservable quality of a product. Whenever product quality if unobservable prior to purchase, there is the risk of adverse selection. Problems of hidden information also occur in the consumer marketplace when the consumer is unable to verify the quality of a good prior to purchase. The sending, receiving, and interpretation or signals are potential ways to overcome the problem of adverse selection. In general, there is a lack of empirical evidence for signaling hypothesis, particularly that which links signaling to business performance outcomes. This research proposes that reputation serves as a marketplace signal to convey unobservable information about products offered for sale. Signaling hypotheses are tested in a network context, examining the influence of signals throughout a network of buyers and sellers in a marketplace. There are many situations where a signal does not affect just one sender and one receiver; multiple constituencies may be aware of and react to a given signal. This study incorporates the actions of seller side principals, seller side agents, and buyer side agents when examining marketplace signals and provides a new perspective and better vantage point from which to test signaling theory. The research setting for this study is the world’s largest individual marketplace for Thoroughbred yearlings. Several sources of secondary data are employed. These openly available published sources of information were selected as representative of the information that would typically be available to marketplace principals and agents to use in planning interactions in this unique live auction marketplace. The findings from his study indicate that the reputation of seller side principals and agents affect the eventual business performance outcomes as measured by final price brought at auction for goods. Specifically, seller side principals and agents who have developed a reputation for producing or selling high-priced or high-performing goods will be rewarded in the marketplace with relatively higher prices for their goods. Buyer side agents who are more central in the marketplace will pay relatively higher prices for goods. Evidence suggests that more central seller side agents will receive relatively higher prices for their goods.

lin-11 and let-711 are early-developmental gene expression regulators with no previously known roles in aging regulation. Yet, they show strong aging-correlated expression profiles (Lund, Tedesco et al. 2002). lin-11 is strongly upregulated in very old worm populations, and let-711 is progressively downregulated in aging worm populations. Microarray studies were performed to identify their genome-wide targets, which were then subjected to further lifespan and genetic analysis to investigate their role in C. elegans aging. The results indicate that the target pools of both lin-11 and let-711 are enriched for aging genes, since a significant number of tested genes increased lifespan. This enrichment of aging genes in their target pools provides strong evidence that lin-11 and let-711 are indeed regulating the expression of aging genes in adult C. elegans. The data suggests that increased lin-11 expression as well as reduced let-711 expression may be promoting longevity by downregulating the insulin/IGF-1 pathway. Decreasing let-711 may also be contributing to longevity by downregulating the germline signaling pathway. K11E4.2, R53.5, C49A9.2 and Y82E9BR.5 are four genes from the lin-11 target pool, whose knockdown produced increases inlifespan. These are unannotated genes, and the details of their roles in aging regulation are not known at this point. ins-3 expression was downregulated two-fold upon knockdown of lin-11, suggesting the possible involvement of lin-11 in regulation of the insulin/IGF-1 pathway. An RNAi construct for ins-3 was not available and it is not known whether loss of ins-3 leads to lifespan extension. let-711 knockdown resulted in an almost four-fold reduction in pdk-1 expression. pdk-1 is an integral part of the insulin/IGF-1 pathway and its knockdown by RNAi extended lifespan. Four other genes from the let-711 target pool that increased lifespan, cdc-25.1, gna-2, meg-1 and ooc-3, all have germline specific functions. The extensions in lifespan generated by these genes were completely dependent on DAF-16. Furthermore, for gna-2, meg-1 or ooc-3, they were independent of DAF-2. These results agree with previously established mechanisms for germline regulation of aging, suggesting the involvement of let-711 in regulating the germline-signaling pathway.

Background: Since the early 1990s, the market for luxury goods has been growing at an unprecedented pace (Granot et al., 2013). Formerly exclusively targeting the richest of the rich, nowadays luxury products are aiming at a broader and considerably younger customer base, the Generation Y (Truong, 2010). Current studies suggest that luxury goods consumption is driven by a need to signal prestige (Grotts & Widner-Johnson, 2013; Nelissen & Meijers, 2011). However, this need can only be fulfilled when a signal is interpreted in the intended way. Nelissen & Meijers (2011) among others believe that a reliable signal can yield “fitness benefits”. Although researchers agree on the outcome of the signaling game, there appears to be no consensus on “what” a product should look like in order to serve as a reliable signal. Purpose: This thesis investigates the impact of brand prominence on perceived “fitness benefits” among Generation Y consumers in the context of luxury fashion clothing. Method: To meet the purpose of this thesis a quantitative study was conducted. The data was collected through a social experiment among students at Högskolan i Jönköping. The participants were randomly presented with one of three visual cues, capturing Brand Prominence by a person wearing t-shirts with differently sized brand logos. An oral survey was then conducted by which the attributed social "fitness" of the depicted person was assessed. Conclusion: The overall results of this study suggest that Brand Prominence has not as much impact on Generation Y consumers than suggested by previous research. Empirical evidence is provided that the signaling process is not as straight forward as proposed by Nelissen & Meijers (2011) or Veblen (1899). The signaling process among Generation Y consumers is (a) influenced by the recipient’s characteristics and (b) by the subtlety of the signal. Furthermore, current studies suggest in accordance with the obtained results a shift form Luxury Consumption to the phenomenon of Luxury Experience. This implies the necessity for luxury manufacturers to adapt to new levels of complexity created by a demographically and geographically heterogeneous consumer landscape, characterized by a new way of Costly Signaling.

In Drosophila, neuropeptides have regulatory roles in development, growth, metabolism and reproduction. This study focused on GABA and the neuropeptides Drosophila tachykinin (DTK), short neuropeptide F (sNPF), adipokinetic hormone (AKH), corazonin (CRZ) and Drosophila insulin-like peptides (DILPs) as possible regulators of metabolic stress responses and homeostasis. We showed that metabotropic GABAB receptors (GBRs) are expressed on brain insulin producing cells (IPCs), suggesting an inhibitory regulation of these cells by GABA. Knockdown of GBR on IPCs shortened lifespan and stress resistance, altered carbohydrate and lipid metabolism at stress (paper I). We showed that three different neuropeptides; DTK, sNPF and ITP, are co-expressed in five pairs of adult neurosecretory cells (paper II). ITP-knock down was not studied yet, but sNPF- and DTK-knock down flies showed decreased stress resistance at desiccation and starvation and decreased water levels at desiccation, suggesting that these peptides are involved in water homeostasis during stress conditions. sNPF was previously shown to affect feeding, growth and DILP expression via the IPCs, but it was not known which sNPF-expressing neurons are responsible for these actions. We could identify a specific set of bilateral neurons (DLPs) that co-express sNPF and corazonin that target the IPCs. We showed that these peptides co-released from DLPs regulate DILP transcription and probably release in the adult Drosophila brain and thus have roles in regulation of stress resistance and metabolism (paper III). AKH signaling was previously shown to affect hemolymph carbohydrate levels and lipid stores in Drosophila. Insulin (DILP) signaling and AKH signaling are suggested to have opposing effects on lipid and sugar metabolism in Drosophila. We studied the possible functional relationship between these two systems; do they mutually regulate each other?  Our results suggest action of DILPs via the Insulin Receptor on the IPCs and the AKH producing cells, but we could not provide evidence for AKH action on IPCs or AKH cells (paper IV). / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 3: Epub ahead of print. Paper 4: Manuscript.</p>

No description available.

The USP4 is a deubiquitinating enzyme found elevated in certain human lung and adrenal tumours. USP4 has a very close relative, USP15, which has caused great difficulty in studying only one or the other. We have had generated two antibodies specific to USP4 and USP15, and have confirmed that the two do not cross react. Although there have been previous findings of interacting partners, possible substrates and pathways in which it is involved, the biological role of USP4 is mostly unknown. We have used these antibodies to determine that USP4 and USP15 expression differs across tissue and cell types, and that expression changes as the organism ages. We have shown that USP4 plays a role in canonical Wnt signaling, perhaps by stabilizing Beta-catenin, and identified GRK2 as a kinase, phosphorylating USP4. These data have provided enough information to form a hypothesis, implicating USP4 with the destruction complex in the Wnt signaling pathway.

Many consumer and medical products contain engineered nanomaterials (ENMs) due to their unique properties arising from their small size of <100 nm in at least one dimension. Although ENMs could greatly improve the quality of daily life, concerns for their health and environmental safety emerged in recent years because the same properties that make ENMs beneficial may also render them toxic. The small size allows ENMs’ entrance into the cell where they may attach to biological molecules and membranes, disrupting their function and/or leading to oxidative stress and/or damage. This thesis focused on silver nanoparticles (AgNPs). Several articles demonstrated that during washing AgNPs are released from the AgNP-impregnated fabrics and could pose a risk to aquatic species. Given that the toxicity mechanisms of AgNPs are yet to be clearly understood this thesis investigated the effects of AgNPs from ‘oxidative stress’ and ‘endocrine disruption’ points of view, using both in vivo and in vitro model fish systems. A 4 d exposure of zebrafish (Danio rerio) embryos to AgNPs increased mortality, delayed hatching, and increased oxidative stress. The silver ion (Ag+) was more effective in eliciting these effects at equivalent silver concentrations. Moreover, the Ag-chelator cysteine reduced the toxicity of both Ag-types. Despite these effects AgNPs or Ag+ did not affect the ability of zebrafish larvae or adults (raised to adulthood in Ag-free water) to increase cortisol levels, but there were differential effects on the expression of corticotropin-releasing factor (CRF)-related genes, suggesting that other physiological processes regulated by CRF may be impacted. Furthermore, a 48 h exposure of rainbow trout (Oncorhynchus mykiss) erythrocytes and hepatocytes to AgNPs or Ag+ increased oxidative stress, but Ag+ was more potent. Moreover, AgNPs elevated lipid peroxidation, while Ag+ increased DNA damage, suggesting different modes of action for the two Ag-types. Cysteine treatment reduced the toxicity of Ag+ and AgNPs, while buthionine sulfoximine, which inhibits glutathione synthesis, increased it, suggesting the importance of glutathione in silver toxicity. Finally, AgNPs increased glycogenolysis in trout hepatocytes independently of the beta-adrenoreceptor or the glucocorticoid receptor.

Normal cellular behaviour in multicellular organisms is achieved by tight control of signaling pathway networks. The mitogen-activated protein kinase (MAPK) signaling cascade is one of these signaling networks, that when deregulated can lead to cellular transformation. Activation of the RAS-RAF-MEK-MAPK (ERK) signal transduction pathway or the SAPK2/p38 pathway results in the activation of mitogen- and stress-activated protein kinases 1 and 2 (MSK1/2). Subsequently, MSKs go on to phosphorylate histone H3 at Ser10 and Ser28.Here, we demonstrate that the activities of ERK and MSK1, but not p38, are elevated in Hras-transformed cells (Ciras-3) relative to these activities in the parental 10T1⁄2 cells. Analyses of the subcellular distribution of MSK1 showed that the H3 kinase was similarly distributed in Ciras-3 and 10T1/2 cells, with most MSK1 being present in the nucleus. In contrast to many other chromatin modifying enzymes, MSK1 was loosely bound in the nucleus and was not a component of the nuclear matrix. Our results provide evidence that oncogene-mediated activation of the RAS-MAPK signal transduction pathway elevates the activity of MSK1, resulting in the increased steady-state levels of phosphorylated H3, which may contribute to the chromatin decondensation and aberrant gene expression observed in oncogene-transformed cells. Furthermore, upon activation of the ERK and p38 MAPK pathways, the MSK1/2- mediated nucleosomal response, including H3 phosphorylation at serine 28 or 10, is coupled with the induction of immediate-early gene transcription. The outcome of this response, varying with the stimuli and cellular contexts, ranges from neoplastic transformation to neuronal synaptic plasticity. Here, we used sequential co-immunoprecipitation assays and chromatin immunoprecipitation (ChIP) assays on mouse fibroblast 10T1/2, Ciras-3 and MSK1 knockdown 10T1/2 cells to show that H3 serine 28 and 10 phosphorylation leads to promoter remodeling. MSK1, in complexes with phospho-serine adaptor 14-3-3 proteins and BRG1 (the ATPase subunit of the SWI/SNF remodeler) is recruited to the promoter of target genes by transcription factors such as ELK-1 or NFκB. Following MSK1-mediated H3 phosphorylation, BRG1 associates with the promoter of target genes via 14-3-3 proteins, which act as scaffolds. The recruited SWI/SNF remodels nucleosomes at the promoter of immediate-early genes enabling the binding of transcription factors like JUN and the onset of transcription. Since RAS-MAPK activated MSKs mediate H3 phosphorylation that is required for expression of various immediate-early gene products involved in cellular transformation, inhibition of MSK activity may be a therapeutic target that could be exploited in cancers with upregulated RAS-MAPK signaling.

The RAS-mitogen-activated protein kinase (MAPK) pathway is an essential signaling mechanism that regulates cellular processes and culminates in the activation of specific gene expression programs. Alterations in the RAS-MAPK signaling cascade can modify epigenetic programs and confer advantages in cell growth and transformation. In fact, deregulation of the cascade is a key event in tumour development with 30% of human cancers harbouring RAS mutations. In breast and pancreatic epithelial cancers, characterization of an aberrant RAS-MAPK pathway has focused on upstream mediators such as receptors and oncogenic RAS molecules but the impact of downstream targets remain poorly defined. Stimulation of the RAS-RAF-MEK-MAPK pathway leads to activation of mitogen- and stress-activated protein kinases 1 and 2 (MSK1/2) which are responsible for the phosphorylation of histone H3 on S10 and S28. We postulate that deregulation of the RAS-MAPK pathway produced by constitutive activation and/ or over-expression of upstream components or mitogen stimulation consequently leads to enhanced MSK1 activity and elevated histone H3 phosphorylation levels. We further hypothesize that MSK1-mediated H3 phosphorylation is critical for immediate early gene (IEG) expression, Ras-driven transformation and is associated with regulatory regions upon gene transcription. In mouse fibroblasts, we present evidence for the critical involvement of MSK1 and H3 phosphorylation as mediators that bridge the aberrant signals driven by the RAS-MAPK pathway with nucleosomal modifications, chromatin remodeling, IEG expression and malignant transformation. We then examined if activation of RAS-MAPK signaling in breast cancer cells elicits similar molecular events. We demonstrate that the RAS-MAPK pathway is induced and enhances the association of MSK1 and H3 phosphorylation on the IEG Trefoil Factor 1 resulting in transcriptional activation. We further observed that mutated K-RAS expression did not correlate with genomic instability or altered signaling in pancreatic cancer cell lines while overexpressed HER2 and EGFR breast cancer cell lines generally exhibit upregulated ERK1/2 and H3 phosphorylation levels. Taken together, our studies contribute to the further understanding of MSK-mediated transcriptional activation in response to RAS-MAPK signaling in oncogene-transformed and cancer cell lines. Inhibition of MSK activity may be an unexplored avenue for combination cancer therapy with abnormal RAS-MAPK signaling pathways.