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This study aimed at determining the recommended dose of the mammalian target of rapamycin inhibitor everolimus in combination with mitomycin C (MMC) in patients with previously treated metastatic esophagogastric cancer. In this phase I trial, patients received escalated doses of oral everolimus (5, 7.5, and 10 mg/day) in combination with intravenous MMC 5 mg/m2 every 3 weeks. Endpoints were the dose-limiting toxicity (DLT), safety, and response rates. Tumor tissues were tested for HER2-status and mutations in the PTEN, PIK3CA, AKT1, CTNNB1, and E-cadherin type 1 genes. Sixteen patients (12 male, four female) with gastric/gastroesophageal junction cancer were included. All patients were previously treated with a platinum-based chemotherapy. Treatment cohorts were: 5 mg/day, three patients; 7.5 mg/day, three patients; and 10 mg/day, 10 patients. No DLTs occurred during dose escalation. Most frequent grade 3 toxicities were leukopenia (18.8%) and neutropenia (18.8%). All other grade 3 toxicities were below 10%. No grade 4 toxicities occurred. Three (18.8%) patients experienced partial responses and four patients had stable disease (SD). Antitumor activity according to Response Evaluation Criteria In Solid Tumors (RECIST)-criteria was highest in the 10 mg/day cohort. No associations between HER2-status or detected mutations and response were observed. The recommended dose of everolimus combined with MMC is 10 mg/day. Encouraging signs of antitumor activity were seen (http://www.ClinicalTrials.gov; Clinical trial registration number: NCT01042782).
Interview mit Matthias Fromm: "In Deutschland fehlt es an Grundoffenheit gegenüber Open Science"
(2013)
Matthias Fromm lebt, studiert und arbeitet in Berlin und zu einem nicht geringen Teil im Internet. Beruflich beschäftigt er sich vor allem mit dem Einsatz von Medientechnologien im Bildungssektor und der Kommunikation in den Bereichen IT und Wissenschaft. Privat bloggt und podcastet er neben Wissenschaftskommunikation über verschiedenste andere Themen, seit Januar diesen Jahres betreibt er zum Beispiel das Open Science Radio. Wir sprachen mit ihm über seine Erfahrungen mit dem Wissenschaftsbloggen, Open Science und Wissenschafts-Crowdfunding.
In der Süddeutschen Zeitung tauchte am vergangenen Montag eine wirklich verblüffende Forderung auf. Der Dresdner Rechtsanwalt Thomas Giesen verstieg sich dort zum Ruf nach einem staatlichen Wissensmonopol, analog zur “mühsam erkämpften Errungenschaft” des Monopols auf legitime Gewaltanwendung. Das Netz “als unzensierter Raum,zugänglich für jeden und für alle noch so verdorbenen Inhalte” – mit dieser hippiesken Träumerei sei es doch nun wirklich einmal genug, so der ehemalige sächsische Datenchutzbeauftragte. Doch wohin ein solches staatliches Wissensmonopol führen kann, demonstrierte in diesen Tagen eindrucksvoll die britische Regierung durch die Festsetzung des Lebensgefährten von Enthüllungsjournalist Glenn Greenwald sowie die Zerstörung von Quellenmaterial des Guardian. Die Sicherheitsbehörden wollen also nicht nur alles wissen, sie wollen darüber verfügen, wer was zu wissen hat und auch die Konsequenzen aus diesem Wissen ungestört verfolgen. Damit gebärden sie sich schon jetzt wie ein Monopolist – und entlarven diese sicher gut gemeinte Idee als totalitäre Phantasie.
Sicherheit über alles?
(2013)
Es tut sich etwas in Folge der Snowden-Leaks: In den USA werden Untersuchungsausschüsse eingesetzt, Vorstöße, die Macht der NSA einzuschränken bzw.transparenter zu gestalten werden stärker – vor allem aber wird es wohl institutionelle Änderungen geben. Und diese hängen an einer Person: Keith Alexander.
Der Bundestag hat in seiner gestrigen Plenardebatte theoretisch über Netzneutralität diskutiert. Theoretisch dadurch, dass die Debatte nur als "Reden zu Protokoll" stattfand, weil die Opposition wohl alle Plenardebatten-Kärtchen bereits gezogen hatte und die Regierungskoalition anscheinend kein großes Interesse an einer öffentlichen Debatte hatten. Konkret ging es um einen Gesetzentwurf der Linksfraktion, die Netzneutralität festzuschreiben. ...
Eine "Gestaltungsmacht" stolpert hinterher – Die deutsche Bundesregierung und die Krise in Mali
(2013)
Im November diagnostizierte ich auf diesem Blog, dass sich Deutschland nach Mali ‚geschlichen‘ habe. Gegenstand dieser Kritik war eine doppelte Zurückhaltung: obwohl die deutsche Bundesregierung recht schnell signalisierte, dass sie sich an einer Trainingsmission für das malische Militär beteiligen würde, blieb der tatsächliche deutsche Beitrag nach außen hin vage und der öffentliche Diskurs über eine Mali-Strategie nach innen nicht existent. Seitdem hat sich einiges getan. Frankreich intervenierte militärisch, die Bundeswehr schickte logistische Unterstützung, die deutsche Öffentlichkeit diskutierte ein wenig und der Bundestag mandatierte die Entsendung der Bundeswehr, wenn auch nicht von Kampftruppen. Trotz dieser Entwicklungen hat sich an der Zurückhaltung der Bundesregierung erstaunlich wenig verändert. Wenn schon konkret gehandelt wird, warum wurde nicht auch der deutsche Regierungsdiskurs vernehmbarer und das Handeln der Bundesregierung konkret greifbarer? Wird eine klare außen- und sicherheitspolitische Position nur elitär aber nicht öffentlich diskutiert und, wenn ja, warum? Oder, so die Vermutung im Folgenden: die deutsche Bundesregierung kann aufgrund der politischen Handlungsnotwendigkeiten nicht mehr schleichen, stolpert den Entwicklungen aber hinterher, weil es weiterhin an einem konkreten und konturierten Gestaltungswillen deutscher Entwicklungs-, Außen- und Sicherheitspolitik und an der strategischen Tiefe der Hilfsmaßnahmen fehlt...
Überwachen und speichern
(2013)
Die neuen sozialen Medien demokratisieren die Berichterstattung. Über Ereignisse wird häufig erst bei Twitter, Google+ und Facebook berichtet, bevor es offizielle Informationen von öffentlichen Stellen oder den konventionellen Medien gibt. Doch das heißt auch: Jeder kann Inhalte anders darstellen, verändern und zu eigenen Zwecken nutzen. Und mehr denn je sind wir darauf angewiesen, dass auch solche direkt kommunizierten Inhalte in den richtigen Zusammenhang gestellt werden. Dafür haben wir die ‘alten’, etablierten Medien mit ihren Redaktionen...
Heute findet in Zusammenarbeit mit der Stiftung Wissenschaft und Politik die dritte Jahreskonferenz des Forschungsprojektes ‘Sicherheitskultur im Wandel‘ statt, das, wie auch das Sipoblog, an der Professur für Internationale Organisation von Christopher Daase an der Universität Frankfurt angesiedelt ist. Diskutiert werden auf der Tagung Optionen und Strategien, mit konkurrierenden sicherheitspolitischen Anforderungen umzugehen und unter Bedingungen der Ungewissheit politische Entscheidungen zu treffen. In vier Panels werden Aspekte des sicherheitskulturellen Wandels kurz und prägnant präsentiert, von Experten aus Politik, Wissenschaft und Medien kommentiert und anschließend im Plenum diskutiert...
Our most recent podcast: We were able to talk to the Japanese culturalanthropologist Mihara Ryôtarô while he visited Frankfurt in July for a talkon the Coool Japan Initiative [link]. As we have written on K-Pop in the past,we were very interested to talk about this kind of export promotion ofcultural goods as a foreign policy strategy: Do export subsidies of J-Popartifacts really promote Japanese soft power in the region? What are thedangers of promoting certain images of Japanese-ness? And is fried sushireally cool?
Unser erster Podcast im Jahr 2013: Wir sprechen mit Juli Zeh, die nicht nur eine profilierte Roman-und Sachbuchautorin ist, sondern die sich als Juristin auch intensiv zu sicherheitspolitische Fragen engagiert. Wir sprechen mit ihr unter anderem über Themen aus ihrem Buch Angriff auf die Freiheit (2009, mit Ilija Trojanow), die Privatsphäre im Internet, biologistische Metaphern in Gefahrenerzählungen, über die Erzählbarkeit von Nicht-Ereignissen, den Wandel der Sicherheitskultur seit dem Kalten Krieg und die Verbesserungsmöglichkeiten demokratischer Sicherheitspolitik.
BACKGROUND: In the heart, cytoplasmic actin networks are thought to have important roles in mechanical support, myofibrillogenesis, and ion channel function. However, subcellular localization of cytoplasmic actin isoforms and proteins involved in the modulation of the cytoplasmic actin networks are elusive. Mena and VASP are important regulators of actin dynamics. Due to the lethal phenotype of mice with combined deficiency in Mena and VASP, however, distinct cardiac roles of the proteins remain speculative. In the present study, we analyzed the physiological functions of Mena and VASP in the heart and also investigated the role of the proteins in the organization of cytoplasmic actin networks.
RESULTS: We generated a mouse model, which simultaneously lacks Mena and VASP in the heart. Mena/VASP double-deficiency induced dilated cardiomyopathy and conduction abnormalities. In wild-type mice, Mena and VASP specifically interacted with a distinct αII-Spectrin splice variant (SH3i), which is in cardiomyocytes exclusively localized at Z- and intercalated discs. At Z- and intercalated discs, Mena and β-actin localized to the edges of the sarcomeres, where the thin filaments are anchored. In Mena/VASP double-deficient mice, β-actin networks were disrupted and the integrity of Z- and intercalated discs was markedly impaired.
CONCLUSIONS: Together, our data suggest that Mena, VASP, and αII-Spectrin assemble cardiac multi-protein complexes, which regulate cytoplasmic actin networks. Conversely, Mena/VASP deficiency results in disrupted β-actin assembly, Z- and intercalated disc malformation, and induces dilated cardiomyopathy and conduction abnormalities.
Eigentlich war für die deutsche Politik der NSA-Spionageskandal ja schon fast erledigt. Doch dann wurde öffentlich, dass Angela Merkels Handy abgehört wurde. Dies resultierte zum Beispiel in verärgerten Anrufen und der Idee eines No-Spy-Abkommen,welches aber inzwischen vom Tisch ist, sowie einer Entschuldigungsabordnung aus den USA, die allerdings einen kalten Empfang in Berlin hatte. Aber nun tut sich auch etwas auf internationaler Ebene: Zusammen mit Brasilien bereitete Deutschland eine Resolution in der UNO Generalversammlung vor, die ein internationales Recht auf Privatsphäre etablieren soll. Inzwischen ist eine,wenn auch abgeschwächte Version, dieser Resolution vom Dritten Komitee verabschiedet worden und wird im Dezember der Generalversammlung vorgelegt. Was bedeutet das für ein mögliches internationales Recht auf Privatsphäre?
Bei Zeit.de findet sich eine Übersicht der Verhandlungsführer für nun beginnenden Koalitionsverhandlungen für eine Große Koalition. Netzpolitik dürfte als Querschnittsthema in mehreren Arbeitsgruppen verhandelt werden. Zuallererst fällt natürlich die Unterarbeitsgruppe Digitale Agenda auf, die der Arbeitsgruppe Kultur zugeordnet ist. Das führte gestern erstmal zu viel Häme auf Twitter, aber diese Zuordnung muss ja erstmal nicht schlecht sein. Viel wichtiger als eine Zuordnung ist ja, wer da was verhandelt. ...
Traue keinem Studenten
(2013)
Für die moderne Universität ist der Studierende an sich vieles: Zentrale Daseinsbegründung, Kostenfaktor, Potenzial, billige Arbeitskraft und seit einigen Jahren in offizieller Sprache auch Kunde. Nun kommt scheinbar eine weitere Facette des Studierenden dazu: das Sicherheitsrisiko.
Versicherheitlichung findet heute in vielen Lebensbereichen statt. Dem Terrorismus wird der Krieg erklärt, ebenso den Drogen oder der Armut. Diese martialische Sprache geht einher mit institutionellen Auswirkungen – wer etwas als ein bedrohliches Problem definiert, reagiert anders als jemand, der es nur als von der normalen Politik zu lösendes Problem betrachtet. Nun haben Studierende es auch in diesen illustren Kreis geschafft – nur nicht aus Sicht des Staates, sondern aus Sicht der Universität und ihrer Abläufe...
Die Koalition hat sich gestern über einen letzten Kompromiss zum Leistungsschutzrecht geeinigt, der heute im federführenden Rechtsausschuss abgestimmt werden soll. Geplant ist, diesen am Freitag nach zweiter und dritter Lesung im Bundestag abzustimmen. Dagegen wehrte sich die Opposition und forderte heute im Rechtsausschuss eine weitere Anhörung, um die veränderten Rahmenbedingungen diskutieren zu können. Das wurde aber mit der Mehrheit der Koalition abgelehnt. ...
“Ohne sie würde der Kampf gegen den islamistischen Terrorismus eines Werkzeugs von ganz entscheidender Wirkung beraubt”. Sie, das ist die Antiterrordatei, die Ende 2006 in Kraft trat und deren Bedeutung Innenminister Friedrich hier betont. Zur “Aufklärung oder Bekämpfung des internationalen Terrorismus mit Bezug zur Bundesrepublik Deutschland” soll sie dienen, die “gemeinsame standardisierte zentrale Antiterrordatei” von 30 bis 40 verschiedenen deutschen Sicherheitsbehörden (auch solcher, die eigentlich nicht mit Terrorabwehr befasst sind). Datenschützer sowie das Verfassungsgericht in Karlsruhe sehen rechtliche sowie eine Reihe von weiteren Problemen bei der Verbunddatei. Was ist sie also, und welche Funktion wiegt schwerer: Effektives Antiterror-Instrument oder Vermischung der strukturellen Grenze zwischen Polizei und Geheimdiensten?...
Natural killer (NK) cells are highly specialized effectors of the innate immune system that hold promise for adoptive cancer immunotherapy. Their cell killing activity is primarily mediated by the pro-apoptotic serine protease granzyme B (GrB), which enters targets cells with the help of the pore-forming protein perforin. We investigated expression of a chimeric GrB fusion protein in NK cells as a means to augment their antitumoral activity. For selective targeting to tumor cells, we fused the epidermal growth factor receptor (EGFR) peptide ligand transforming growth factor α (TGFα) to human pre-pro-GrB. Established human NKL natural killer cells transduced with a lentiviral vector expressed this GrB-TGFα (GrB-T) molecule in amounts comparable to endogenous wildtype GrB. Activation of the genetically modified NK cells by cognate target cells resulted in the release of GrB-T together with endogenous granzymes and perforin, which augmented the effector cells' natural cytotoxicity against NK-sensitive tumor cells. Likewise, GrB-T was released into the extracellular space upon induction of degranulation with PMA and ionomycin. Secreted GrB-T fusion protein displayed specific binding to EGFR-overexpressing tumor cells, enzymatic activity, and selective target cell killing in the presence of an endosomolytic activity. Our data demonstrate that ectopic expression of a targeted GrB fusion protein in NK cells is feasible and can enhance antitumoral activity of the effector cells.
Background and Aims: Mutations reducing the function of Nav1.7 sodium channels entail diminished pain perception and olfactory acuity, suggesting a link between nociception and olfaction at ion channel level. We hypothesized that if such link exists, it should work in both directions and gain-of-function Nav1.7 mutations known to be associated with increased pain perception should also increase olfactory acuity.
Methods: SCN9A variants were assessed known to enhance pain perception and found more frequently in the average population. Specifically, carriers of SCN9A variants rs41268673C>A (P610T; n = 14) or rs6746030C>T (R1150W; n = 21) were compared with non-carriers (n = 40). Olfactory function was quantified by assessing odor threshold, odor discrimination and odor identification using an established olfactory test. Nociception was assessed by measuring pain thresholds to experimental nociceptive stimuli (punctate and blunt mechanical pressure, heat and electrical stimuli).
Results: The number of carried alleles of the non-mutated SCN9A haplotype rs41268673C/rs6746030C was significantly associated with the comparatively highest olfactory threshold (0 alleles: threshold at phenylethylethanol dilution step 12 of 16 (n = 1), 1 allele: 10.6±2.6 (n = 34), 2 alleles: 9.5±2.1 (n = 40)). The same SCN9A haplotype determined the pain threshold to blunt pressure stimuli (0 alleles: 21.1 N/m2, 1 allele: 29.8±10.4 N/m2, 2 alleles: 33.5±10.2 N/m2).
Conclusions: The findings established a working link between nociception and olfaction via Nav1.7 in the gain-of-function direction. Hence, together with the known reduced olfaction and pain in loss-of-function mutations, a bidirectional genetic functional association between nociception and olfaction exists at Nav1.7 level.
Background and Aims: The Roadmap concept is a therapeutic framework in chronic hepatitis B for the intensification of nucleoside analogue monotherapy based on early virologic response. The efficacy and safety of this approach applied to telbivudine treatment has not been investigated.
Methods: A multinational, phase IV, single-arm open-label study (ClinicalTrials.gov ID NCT00651209) was undertaken in HBeAg-positive, nucleoside-naive adult patients with chronic hepatitis B. Patients received telbivudine (600 mg once-daily) for 24 weeks, after which those with undetectable serum HBV DNA (<300 copies/mL) continued to receive telbivudine alone while those with detectable DNA received telbivudine plus tenofovir (300 mg once-daily). Outcomes were assessed at Week 52.
Results: 105 patients commenced telbivudine monotherapy, of whom 100 were included in the efficacy analysis. Fifty-five (55%) had undetectable HBV DNA at Week 24 and continued telbivudine monotherapy; 45 (45%) received tenofovir intensification. At Week 52, the overall proportion of undetectable HBV DNA was 93% (93/100) by last-observation-carried-forward analysis (100% monotherapy group, 84% intensification group) and no virologic breakthroughs had occurred. ALT normalization occurred in 77% (87% monotherapy, 64% intensification), HBeAg clearance in 43% (65% monotherapy, 16% intensification), and HBeAg seroconversion in 39% (62% monotherapy, 11% intensification). Six patients had HBsAg clearance. Myalgia was more common in the monotherapy group (19% versus 7%). No decrease in the mean glomerular filtration rate occurred in either treatment group at Week 52.
Conclusions: Telbivudine therapy with tenofovir intensification at Week 24, where indicated by the Roadmap strategy, appears effective and well tolerated for the treatment of chronic hepatitis B.
Trial Registration: ClinicalTrials.gov NCT00651209
BACKGROUND: To report the clinical outcome of high dose rate brachytherapy as sole treatment for clinically localised prostate cancer.
METHODS: Between March 2004 and January 2008, a total of 351 consecutive patients with clinically localised prostate cancer were treated with transrectal ultrasound guided high dose rate brachytherapy. The prescribed dose was 38.0 Gy in four fractions (two implants of two fractions each of 9.5 Gy with an interval of 14 days between the implants) delivered to an intraoperative transrectal ultrasound real-time defined planning treatment volume. Biochemical failure was defined according to the Phoenix Consensus and toxicity evaluated using the Common Toxicity Criteria for Adverse Events version 3.
RESULTS: The median follow-up time was 59.3 months. The 36 and 60 month biochemical control and metastasis-free survival rates were respectively 98%, 94% and 99%, 98%. Toxicity was scored per event with 4.8% acute Grade 3 genitourinary and no acute Grade 3 gastrointestinal toxicity. Late Grade 3 genitourinary and gastrointestinal toxicity were respectively 3.4% and 1.4%. No instances of Grade 4 or greater acute or late adverse events were reported.
CONCLUSIONS: Our results confirm high dose rate brachytherapy as safe and effective monotherapy for clinically organ-confined prostate cancer.
Fire is the primary disturbance factor in many terrestrial ecosystems. Wildfire alters vegetation structure and composition, affects carbon storage and biogeochemical cycling, and results in the release of climatically relevant trace gases including CO2, CO, CH4, NOx, and aerosols. One way of assessing the impacts of global wildfire on centennial to multi-millennial timescales is to use process-based fire models linked to dynamic global vegetation models (DGVMs). Here we present an update to the LPJ-DGVM and a new fire module based on SPITFIRE that includes several improvements to the way in which fire occurrence, behaviour, and the effects of fire on vegetation are simulated. The new LPJ-LMfire model includes explicit calculation of natural ignitions, the representation of multi-day burning and coalescence of fires, and the calculation of rates of spread in different vegetation types. We describe a new representation of anthropogenic biomass burning under preindustrial conditions that distinguishes the different relationships between humans and fire among hunter-gatherers, pastoralists, and farmers. We evaluate our model simulations against remote-sensing-based estimates of burned area at regional and global scale. While wildfire in much of the modern world is largely influenced by anthropogenic suppression and ignitions, in those parts of the world where natural fire is still the dominant process (e.g. in remote areas of the boreal forest and subarctic), our results demonstrate a significant improvement in simulated burned area over the original SPITFIRE. The new fire model we present here is particularly suited for the investigation of climate–human–fire relationships on multi-millennial timescales prior to the Industrial Revolution.
Inhibitors of Apoptosis Proteins (IAPs) are a class of highly conserved proteins predominantly known for the regulation of caspases and immune signaling. However, recent evidence suggests a crucial role for these molecules in the regulation of tumor cell shape and migration by controlling MAPK, NF-κB and Rho GTPases. IAPs directly control Rho GTPases, thus regulating cell shape and migration. For instance, XIAP and cIAP1 function as the direct E3 ubiquitin ligases of Rac1 and target it for proteasomal degradation. IAPs are differentially expressed in tumor cells and have been targeted by several cancer therapeutic drugs that are currently in clinical trials. Here, we summarize the current knowledge on the role of IAPs in the regulation of cell migration and discuss the possible implications of these observations in regulating tumor cell metastases.
Background: Cannabinoid receptor 1 (CB1) is expressed in certain types of malignancies. An analysis of CB1 expression and function in Hodgkin lymphoma (HL), one of the most frequent lymphomas, was not performed to date.
Design and Methods: We examined the distribution of CB1 protein in primary cases of HL. Using lymphoma derived cell lines, the role of CB1 signaling on cell survival was investigated.
Results: A predominant expression of CB1 was found in Hodgkin-Reed-Sternberg cells in a vast majority of classical HL cases. The HL cell lines L428, L540 and KM-H2 showed strong CB1-abundance and displayed a dose-dependent decline of viability under CB1 inhibition with AM251. Further, application of AM251 led to decrease of constitutively active NFκB/p65, a crucial survival factor of HRS-cells, and was followed by elevation of apoptotic markers in HL cells.
Conclusions: The present study identifies CB1 as a feature of HL, which might serve as a potential selective target in the treatment of Hodgkin lymphoma.
The first reports of the multicolored Asian lady beetle Harmonia axyridis (Pallas, 1773) (Coleoptera: Coccinellidae) in Colombia appeared in 2011. However, based on museum insect specimens, the introduction of H. axyridis in Colombia occurred in 1989 or earlier, making it the second oldest record of the species in South America after the deliberate releases of the species in Argentina in 1986. Currently in Colombia, H. axyridis is well established and is here recorded from the States of Antioquia, Caldas, Cauca, Cundinamarca, Nariño, Tolima and Valle del Cauca.
Die vorliegende Arbeit befasst sich mit der gegenwärtigen Situation der indigenen Bevölkerung in den Vereinigten Staaten von Amerika. Dort erleben viele Indianerstämme in jüngster Zeit einen nie dagewesenen wirtschaftlichen Aufschwung, der ihre bis dato äußerst ärmlichen Lebensverhältnisse grundlegend verbessert. Vor etwas mehr als zwei Jahrzehnten trat ein Gesetz in Kraft, das es den Stämmen gestattete, relativ unbehindert von einzelstaatlichen Restriktionen und Steuerbelastungen innerhalb ihrer Reservationsgebiete Glücksspiele für nichtindianische Besucher zu veranstalten. Seither haben sowohl Anzahl wie auch Gewinne der stammeseigenen Spielbetriebe in einem Maße zugenommen, das alle anfänglichen Erwartungen längst übertroffen hat. Tribal Gaming (oft auch Indian Gaming) ist zwar ein noch relativ rezentes Phänomen, doch es kann bereits jetzt festgestellt werden, dass es seit dem Beginn der europäischen Dominanz in Nordamerika keine Wirtschaftsstrategie gegeben hat, aus der so viele Indianerstämme gleichzeitig einen derart großen finanziellen Nutzen ziehen konnten. Für viele – wenn auch bei weitem nicht für alle – Indianerstämme ist das Kasino oder die Bingohalle inzwischen zur Haupteinnahmequelle geworden.
Die Untersuchung konzentriert sich auf die Auswirkungen dieses fundamentalen Wandels auf die indianischen Gemeinschaften insbesondere unter dem Gesichtspunkt der kulturellen und gesellschaftlichen Erneuerung und im weiteren Kontext auch auf ihre veränderte Rolle als Akteure im politischen System der USA. Im Mittelpunkt stehen also weniger die wirtschaftlichen Aspekte, als vielmehr die Frage, welchen Beitrag die stammeseigenen Glücksspielunternehmen als Instrument zur kulturellen, gesellschaftlichen und politischen Revitalisierung der indigenen Gesellschaften leisten können...
Eine empirische Arbeit, auf Basis der teilnehmenden Beobachtung nach Malinowski, bei Dealern im bürgerlichen Milieu. Der Fokus liegt auf einer ethnologischen Herangehensweise; d.h., dass am Leben der Dealer weitestgehend und möglichst vorurteilsfrei teilgenommen wird. Hieraus ergeben sich Einblicke, die mit anderen Forschungsmethoden nicht möglich sind.
Das CEDEFOP koordiniert ab dem 1. Januar 2008 bis 2013 im Auftrag der Kommission die Studienbesuche für Bildungs- und Berufsbildungsfachleute und Entscheidungsträger. Ein Studienbesuch verläuft folgendermaßen: eine kleine Gruppe von Experten und Entscheidungsträgern, die verschiedene Bildungs- und Berufsbildungsgruppen vertreten, besuchen drei bis fünf Tage einen Mitgliedstaat der EU, um dort einen bestimmten Aspekt des lebenslangen Lernens zu untersuchen.
ATP synthases are multi-subunit membrane enzymes, which utilize the energy stored in a transmembrane electrochemical ion gradient to produce adenosine-5´-triphosphate (ATP), the universal energy carrier in biological systems. Research on these important enzymes goes back more than 50 years and has produced innumerable studies. The F-type ATP synthase consists of two functionally distinct, but tightly coupled subcomplexes, the water-soluble F1 and the membrane-embedded Fo complex. In its simplest form, F1 consists of five different subunits with a stoichiometry of α 3β3γδε, and harbors three catalytic centers in the α 3β3-headpiece, while Fo consists of three different subunits in a stoichiometry of ab2cn, where n varies between 8 to 15 depending on the species. From a mechanistic standpoint, the complex can also be divided into two different units, namely a stator, α3β3δ-ab2, and a rotor, γε-cn. The enzyme utilizes the energy stored in a transmembrane electrochemical gradient of protons, or in some cases Na+, to drive ATP synthesis. In particular, the downhill translocation of these ions across the Fo complex drives rotation of the γε-cn unit, which is then transduced to the active centers, catalyzing the phosphorylation of adenosine-5`-diphosphate (ADP) with inorganic phosphate (Pi), and the release of ATP....
A new type of Na+-driven ATP synthase membrane rotor with a two-carboxylate ion-coupling motif
(2013)
Abstract: The anaerobic bacterium Fusobacterium nucleatum uses glutamate decarboxylation to generate a transmembrane gradient of Na+. Here, we demonstrate that this ion-motive force is directly coupled to ATP synthesis, via an F1Fo-ATP synthase with a novel Na+ recognition motif, shared by other human pathogens. Molecular modeling and free-energy simulations of the rotary element of the enzyme, the c-ring, indicate Na+ specificity in physiological settings. Consistently, activity measurements showed Na+ stimulation of the enzyme, either membrane-embedded or isolated, and ATP synthesis was sensitive to the Na+ ionophore monensin. Furthermore, Na+ has a protective effect against inhibitors targeting the ion-binding sites, both in the complete ATP synthase and the isolated c-ring. Definitive evidence of Na+ coupling is provided by two identical crystal structures of the c11 ring, solved by X-ray crystallography at 2.2 and 2.6 Å resolution, at pH 5.3 and 8.7, respectively. Na+ ions occupy all binding sites, each coordinated by four amino acids and a water molecule. Intriguingly, two carboxylates instead of one mediate ion binding. Simulations and experiments demonstrate that this motif implies that a proton is concurrently bound to all sites, although Na+ alone drives the rotary mechanism. The structure thus reveals a new mode of ion coupling in ATP synthases and provides a basis for drug-design efforts against this opportunistic pathogen.
Author Summary: Essential cellular processes such as biosynthesis, transport, and motility are sustained by the energy released in the hydrolysis of ATP, the universal energy carrier in living cells. Most ATP in the cell is produced by a membrane-bound enzyme, the ATP synthase, through a rotary mechanism that is coupled to the translocation of ions across the membrane. The majority of ATP synthases are energized by transmembrane electrochemical gradients of protons (proton-motive force), but a number of organisms, including some important human pathogens, use gradients of sodium ions instead (sodium-motive force). The ion specificity of ATP synthases is determined by a membrane-embedded sub-complex, the c-ring, which is the smallest known biological rotor. The functional mechanism of the rotor ring and its variations among different organisms are of wide interest, because of this enzyme's impact on metabolism and disease, and because of its potential for nanotechnology applications. Here, we characterize a previously unrecognized type of Na+-driven ATP synthase from the opportunistic human pathogen Fusobacterium nucleatum, which is implicated in periodontal diseases. We analyzed this ATP synthase and its rotor ring through a multi-disciplinary approach, combining cell-growth and biochemical assays, X-ray crystallography and computer-simulation methods. Two crystal structures of the membrane rotor were solved, at low and high pH, revealing an atypical ion-recognition motif mediated by two carboxylate side-chains. This motif is shared by other human pathogens, such as Mycobacterium tuberculosis or Streptococcus pneumonia, whose ATP synthases are targets of novel antibiotic drugs. The implications of this ion-recognition mode on the mechanism of the ATP synthase and the cellular bioenergetics of F. nucleatum were thus examined. Our results provide the basis for future pharmacological efforts against this important pathogen.
Juvenile Neuronal Ceroid Lipofuscinosis (JNCL) is a rare inherited childhood neurodegenerative disease that is caused by a mutation in the gene CLN3. The function of the protein produced by the gene has remained elusive, and therefore the disease mechanism of JNCL is as of yet unknown. The disease is fatal, and no cure is currently available. We believe that simvastatin shows promise as a possible treatment. Simvastatin is well tolerated in children, and as currently no other viable, less invasive treatment for JNCL exists, at least pilot-scale clinical trials for this new off-label use of simvastatin are warranted.
The protein CLN3 has been indicated to have several different subcellular localizations and functions, but conclusive evidence about its role in cellular metabolism is lacking. It is also unclear why the mutation causes the distinct phenotype of the JNCL disease. In order to bring lucidity to the issue, we set out to identify metabolic pathways related to the phenotype of JNCL by using Multi-Epitope Ligand Cartography (MELC) and the related field of toponomics. Toponomic methods are required to process the massive amount of data generated by the MELC runs in order to extract information from them.
Our disease model of choice was the CLN3Δex7/8 knock-in mouse. To separate cause from effect, we compared embryonal wild type and mutant mouse brains to their adult counterparts. The first analyses revealed progressively abnormal Combinatorial Molecular Patterns (CMPs, an unit of toponomic data) related to cholera toxin/ganglioside 1 (Ctx/GM1), which is a membrane microdomain marker.
Cholesterol is an essential part of microdomains, so we utilized filipin staining to see if there were actual changes in cholesterol concentration and localization between healthy and diseased animals. After the disturbance in cholesterol metabolism was verified, we investigated the metabolic pathway that synthesizes cholesterol, the mevalonate pathway. Simvastatin is a drug that specifically down-regulates the mevalonate pathway. Fish oil affects lipid homeostasis and has some effects similar to those of simvastatin, and both of these drugs have previously been studied for their effects on neurodegenerative diseases. After treatment of mice with these drugs, highperformance liquid chromatography (HPLC) measurements on the brain homogenate showed a decrease in levels of farnesyl pyrophosphate (FPP) and geranyl-geranyl pyrophosphate (GGPP), products of the mevalonate pathway, confirming the effect of these drugs on the brains of the animals. Analyses of motor function of the mice further supported the notion that simvastatin had a positive effect on the condition of the diseased animals.
CMP analyses from the simvastatin treated mice showed a rescue of the Ctx/GM1 CMPs, suggesting at least a partial restoration of membrane microdomain homeostasis. Filipin staining revealed reversion of the apparent cholesterol depletion in the adult mutant mouse hippocampus by simvastatin. Interestingly, an additional effect of the treatment was found: simvastatin also affected glutamate receptor homeostasis, especially as regarding to N-methyl-D-aspartate (NMDA) and alphaamino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) receptors. This finding suggested that excitotoxicity could be a part of the disease process, and pointed towards glutamate receptors as possible therapy targets. This is in line with previous studies that have shown that attenuation of AMPA receptors and L voltage-dependent channels improve the phenotype of a JNCL mouse and cell model, respectively.
Simvastatin mediates many of its effects via downregulation of the mevalonate pathway products, such as isoprenoids and cholesterol. However, simvastatin also has multiple pleiotropic effects that include suppression of excitotoxicity and granting neuroprotection. It is apparent that simvastatin treatment has a positive effect on JNCL mice, but if its effects are mediated via cholesterol (and membrane microdomains), isoprenoids (and isoprenylated proteins) or via a fully cholesterol independent mechanism remains to be solved.
In this study we have shown that with the MELC method and toponomics it is possible to approach rare diseases with confounded disease mechanisms with a hypothesis-free approach, to identify possible drug targets, and to monitor the effects of the drugs on treated individuals. This should open up a new avenue in the research of the many diseases that so far have avoided all attempts at discerning their nature.
Cell-cell adhesion is an essential process during the development of multicellular organisms. It is based on various cellular junctions and ensures a tight contact between neighboring cells, enabling interactive exchanges necessary for morphological and functional differentiation and maintaining the homeostasis of healthy tissue organization. Two important types of cell-cell adhesions are the adherens junction (AJ) and the desmosome which link the actin cytoskeleton and intermediate filaments to cadherin-based adhesion sites. The core of these structures is composed of single-span transmembrane proteins of the cadherin superfamily which include, among other members, the classical cadherins, e.g. E-cadherin, as well as the desmosomal cadherins, e.g. desmoglein-3. The cytoplasmic domains of the desmosomal and classical cadherins enable interactions with proteins of the catenin family. Classical cadherins preferentially associate with β-catenin and p120-catenin, whereas desmosomal cadherins bind to γ-catenin and plakophilins. Intriguingly, γ-catenin, also known as plakoglobin, is so far the only protein known to be present both in the AJ and the desmosome.
In this study, we showed that the two homologous, membrane raft-associated proteins flotillin-1 and flotillin-2 associate with core proteins of the AJ and the desmosome in vitro and in vivo. In confluent human, non-malignant epithelial MCF10A cells and human skin cryosections, flotillin-2 colocalized with E-cadherin, desmoglein-3 and γ-catenin at cell-cell contact sites, whereas flotillin-1 showed barely any overlap with these proteins. In addition, we detected a colocalization of both flotillins with the actin-binding protein α-actinin in membrane ruffles in subconfluent and at cell-cell contact sites in confluent MCF10A cells as well as in human skin cryosections. The interaction with α-actinin was later shown to be flotillin-1 dependent by performing indirect GST pulldown experiments with purified α-actinin-1-GST in MCF10A cell lysates.
Since flotillin-2 strongly colocalized with cell-cell junctions, this suggested that flotillins might be found in complex with cell adhesion proteins. Thus, we performed coimmunoprecipitation experiments in murine skin lysates and various cell lines of epithelial origin, such as human breast cancer MCF7 cells, human keratinocyte HaCaT cells and primary mouse keratinocytes. These experiments demonstrated that flotillins, especially flotillin-2, coprecipitated with E-cadherin, desmosomal cadherins and γ-catenin in relation to the respective cell type and the maturation status of these cell-cell adhesion structures. However, since γ-catenin is so far the only protein known to be present in the AJ and the desmosome, we further assumed that the complex formation of flotillins with cell adhesion structures is mediated by γ-catenin. For this, we performed indirect GST pulldown experiments in MCF10A cell lysates with bacterially expressed, purified flotillin-1-GST, flotillin-2-GST and γ-catenin-GST and were able to verify the complex formation of adhesion proteins and flotillins in vitro. To further test if the interaction of γ-catenin and flotillins is a direct one, we used purified flotillin-1-GST or flotillin-2-GST and γ-catenin-MBP fusion proteins. Both flotillins directly interacted with γ-catenin in this in vitro assay. In addition, mapping of the interaction domains in γ-catenin by using GST fusion proteins carrying different parts of γ-catenin suggested that flotillins bind to a discontinuous γ-catenin binding domain which consists of a Major determinant around ARM domains 6-12, most likely with a major contribution of the ARM domain 7, and possibly including the NT part of γ-catenin.
To study the effect of flotillin depletion on cell-cell adhesion, we generated stable MCF10A cell lines in which flotillins were knocked down by means of lentiviral shRNAs. Staining of E-cadherin and γ-catenin in these cells showed that the localization at the cell-cell borders was significantly altered after flotillin-2 depletion, which pointed to a role for flotillin-2 in the formation of cell-cell adhesion structures in epithelial cells. Furthermore, isolation of detergent resistant membranes (DRMs) from these cells demonstrated that upon depletion of flotillin-2, a significant amount of E-cadherin and γ-catenin shifted into raft fractions. On the contrary, no change was detected in flotillin-1 knockdown cells. These observations point to a functional role of flotillin-2 in the regulation of raft association of cell-cell adhesion proteins. To gain more insight into the in vivo relevance of our findings, we next studied the function of flotillins in the skin of Flot2-/- knockout mice. Analysis of lysates prepared from the skin of one year old female animals revealed an increased expression of E-cadherin, desmoglein-1 and γ-catenin but not β-catenin, implicating that specific adhesion proteins are upregulated in flotillin-2 knockout skin.
Since flotillins are tightly associated with membrane microdomains we next studied the interaction of flotillin-2 with membrane cholesterol. Using the photoreactive cholesterol analog azocholestanol, we were able to show that flotillin-2 and cholesterol directly interacted. In addition, previous studies speculated that flotillin-2 interacts with cholesterol via two putative cholesterol recognition/interaction amino acid consensus (CRAC) motifs. Analysis of the flotillin-2 sequence revealed that flotillin-2 actually contains four putative CRAC motifs. However, using various flotillin-2 CRAC mutant GFP fusion proteins, we were able to show that none of the putative CRAC motifs is functional, which suggested that flotillin-2 interacts with membrane cholesterol, e.g., via posttranslational modifications, such as myristoylation and palmitoylation which were previously shown to be essential for membrane association of flotillin proteins.
Because of its highly bioactive properties sphingosine 1-phosphate (S1P) is an attractive target for the treatment of several diseases. Since the expression of sphingosine kinases as well as S1P receptors was demonstrated in the kidney, questions about the physiological and pathophysiological functions of S1P in this organ have been raised. In this review, we summarize the current state of knowledge about S1P-mediated functions in the kidney. A special focus is put on S1P modulated signal transduction in renal glomerular and tubular cells and consequences for the development and treatment of several kidney diseases, diabetic nephropathy, glomerulonephritis, ischemia-reperfusion injury, as well as for Wilms tumor progression.
This study indicates that embryonic stem cells [ESCs] cultured with retinoic acid and activin A significantly upregulate the miRNA let-7e. This specific miRNA modulates the Wnt pathway and the expression of early nephrogenic markers under these differentiation conditions. The differentiation markers WT1, Pax2 and Wnt4 were downregulated when miRNA let-7e was silenced, thus indicating the role of miRNA let-7e in the differentiation process. PKCβ, GSK3β phosphorylation (GSK3βP) and β-catenin expression was reduced in differentiated cells and reversed by miRNA let-7e silencing. Addition of a PKCβ inhibitor to the miRNA let-7e silenced cells abolished let-7e-derived effects in differentiation markers, and reversed the increase in GSK3βP and β-catenin, thus indicating that miRNA let-7e is involved in differentiation via the modulation of GSK3β phosphorylation and β-catenin production.
The role of the mRNA-binding protein human antigen R (HuR) in stabilization and translation of AU-rich elements (ARE) containing mRNAs is well established. However, the trafficking of HuR and bound mRNA cargo, which comprises a fundamental requirement for the aforementioned HuR functions is only poorly understood. By administering different cytoskeletal inhibitors, we found that the protein kinase Cδ (PKCδ)-triggered accumulation of cytoplasmic HuR by Angiotensin II (AngII) is an actin-myosin driven process functionally relevant for stabilization of ARE-bearing mRNAs. Furthermore, we show that the AngII-induced recruitment of HuR and its bound mRNA from ribonucleoprotein particles to free and cytoskeleton bound polysomes strongly depended on an intact actomyosin cytoskeleton. In addition, HuR allocation to free and cytoskeletal bound polysomes is highly sensitive toward RNase and PPtase and structurally depends on serine 318 (S318) located within the C-terminal RNA recognition motif (RRM3). Conversely, the trafficking of the phosphomimetic HuRS318D, mimicking HuR phosphorylation at S318 by the PKCδ remained PPtase resistant. Co-immunoprecipitation experiments with truncated HuR proteins revealed that the stimulus-induced association of HuR with myosin IIA is strictly RNA dependent and mediated via the RRM3. Our data implicate a microfilament dependent transport of HuR, which is relevant for stimulus-induced targeting of ARE-bearing mRNAs from translational inactive ribonucleoprotein particles to polysomes.
Peripheral sensitization during inflammatory pain is mediated by a variety of endogenous proalgesic mediators including a number of oxidized lipids, some of which serve endogenous modulators of sensory TRP-channels. These lipids are eicosanoids of the arachidonic acid and linoleic acid pathway, as well as lysophophatidic acids (LPAs). However, their regulation pattern during inflammatory pain and their contribution to peripheral sensitization is still unclear. Here, we used the UVB-model for inflammatory pain to investigate alterations of lipid concentrations at the site of inflammation, the dorsal root ganglia (DRGs) as well as the spinal dorsal horn and quantified 21 lipid species from five different lipid families at the peak of inflammation 48 hours post irradiation. We found that known proinflammatory lipids as well as lipids with unknown roles in inflammatory pain to be strongly increased in the skin, whereas surprisingly little changes of lipid levels were seen in DRGs or the dorsal horn. Importantly, although there are profound differences between the number of cytochrome (CYP) genes between mice and rats, CYP-derived lipids were regulated similarly in both species. Since TRPV1 agonists such as LPA 18:1, 9- and 13-HODE, 5- and 12-HETE were elevated in the skin, they may contribute to thermal hyperalgesia and mechanical allodynia during UVB-induced inflammatory pain. These results may explain why some studies show relatively weak analgesic effects of cyclooxygenase inhibitors in UVB-induced skin inflammation, as they do not inhibit synthesis of other proalgesic lipids such as LPA 18:1, 9-and 13-HODE and HETEs.
Interleukin (IL)-10 and IL-22 are key members of the IL-10 cytokine family that share characteristic properties such as defined structural features, usage of IL-10R2 as one receptor chain, and activation of signal transducer and activator of transcription (STAT)-3 as dominant signaling mode. IL-10, formerly known as cytokine synthesis inhibitory factor, is key to deactivation of monocytes/macrophages and dendritic cells. Accordingly, pre-clinical studies document its anti-inflammatory capacity. However, the outcome of clinical trials assessing the therapeutic potential of IL-10 in prototypic inflammatory disorders has been disappointing. In contrast to IL-10, IL-22 acts primarily on non-leukocytic cells, in particular epithelial cells of intestine, skin, liver, and lung. STAT3-driven proliferation, anti-apoptosis, and anti-microbial tissue protection is regarded a principal function of IL-22 at host/environment interfaces. In this hypothesis article, hidden/underappreciated pro-inflammatory characteristics of IL-10 and IL-22 are outlined and related to cellular priming by type I interferon. It is tempting to speculate that an inherent inflammatory potential of IL-10 and IL-22 confines their usage in tissue protective therapy and beyond that determines in some patients efficacy of type I interferon treatment.
Objective. To test the influence of personalized ultrasound (PersUS) on patient management in critical care. Design of the Study. Prospective, observational, and critical care setting. Four substudies compared PersUS and mobile ultrasound, work distribution, and diagnostic and procedural quality. Patients and Interventions. 640 patient ultrasound exams including 548 focused diagnostic exams and 92 interventional procedures. Main Outcome Measures. Number of studies, physician’s judgement of feasibility, time of usage per patient, and referrals to echo lab. Results. Randomized availability of PersUS increased its application in ICU work shifts more than twofold from 33 to 68 exams mainly for detection and therapy of effusions. Diagnostic and procedural quality was rated as excellent/very good in PersUS-guided puncture in 95% of cases. Integrating PersUS within an initial physical examination of 48 randomized cases in an emergency department, PersUS extended the examination time by 100 seconds. Interestingly, PersUS integration into 53 randomized regular ward rounds of 1007 patients significantly reduced average contact time per patient by 103 seconds from 8.9 to 7.2 minutes. Moreover, it lowered the patient referral rate to an echo lab from 20% to 2% within the study population. Conclusions. We propose the development of novel ultrasound-based clinical pathways by integration of PersUS.
Background: One of the most popular and versatile model of murine melanoma is by inoculating B16 cells in the syngeneic C57BL6J mouse strain. A characterization of different B16 modified cell sub-lines will be of real practical interest. For this aim, modern analytical tools like surface enhanced Raman spectroscopy/scattering (SERS) and MTT were employed to characterize both chemical composition and proliferation behavior of the selected cells.
Methods: High quality SERS signal was recorded from each of the four types of B16 cell sub-lines: B164A5, B16GMCSF, B16FLT3, B16F10, in order to observe the differences between a parent cell line (B164A5) and other derived B16 cell sub-lines. Cells were incubated with silver nanoparticles of 50–100 nm diameter and the nanoparticles uptake inside the cells cytoplasm was proved by transmission electron microscopy (TEM) investigations. In order to characterize proliferation, growth curves of the four B16 cell lines, using different cell numbers and FCS concentration were obtained employing the MTT proliferation assay. For correlations doubling time were calculated.
Results: SERS bands allowed the identification inside the cells of the main bio-molecular components such as: proteins, nucleic acids, and lipids. An "on and off" SERS effect was constantly present, which may be explained in terms of the employed laser power, as well as the possible different orientations of the adsorbed species in the cells in respect to the Ag nanoparticles. MTT results showed that among the four tested cell sub-lines B16 F10 is the most proliferative and B164A5 has the lower growth capacity. Regarding B16FLT3 cells and B16GMCSF cells, they present proliferation ability in between with slight slower potency for B16GMCSF cells.
Conclusion: Molecular fingerprint and proliferation behavior of four B16 melanoma cell sub-lines were elucidated by associating SERS investigations with MTT proliferation assay.
CD69 is a transmembrane lectin that can be expressed on most hematopoietic cells. In monocytes, it has been functionally linked to the 5-lipoxygenase pathway in which the leukotrienes, a class of highly potent inflammatory mediators, are produced. However, regarding CD69 gene expression and its regulatory mechanisms in monocytes, only scarce data are available. Here, we report that CD69 mRNA expression, analogous to that of 5-lipoxygenase, is induced by the physiologic stimuli transforming growth factor-β (TGF-β) and 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3) in monocytic cells. Comparison with T- and B-cell lines showed that the effect was specific for monocytes. CD69 expression levels were increased in a concentration-dependent manner, and kinetic analysis revealed a rapid onset of mRNA expression, indicating that CD69 is a primary TGF-β/1α,25(OH)2D3 target gene. PCR analysis of different regions of the CD69 mRNA revealed that de novo transcription was initiated and proximal and distal parts were induced concomitantly. In common with 5-lipoxygenase, no activation of 0.7 kb or ~2.3 kb promoter fragments by TGF-β and 1α,25(OH)2D3 could be observed in transient reporter assays for CD69. Analysis of mRNA stability using a transcription inhibitor and a 3′UTR reporter construct showed that TGF-β and 1α,25(OH)2D3 do not influence CD69 mRNA stability. Functional knockdown of Smad3 clearly demonstrated that upregulation of CD69 mRNA, in contrast to 5-LO, depends on Smad3. Comparative studies with different inhibitors for mitogen activated protein kinases (MAPKs) revealed that MAPK signalling is involved in CD69 gene regulation, whereas 5-lipoxygenase gene expression was only partly affected. Mechanistically, we found evidence that CD69 gene upregulation depends on TAK1-mediated p38 activation. In summary, our data indicate that CD69 gene expression, conforming with 5-lipoxygenase, is regulated monocyte-specifically by the physiologic stimuli TGF-β and 1α,25(OH)2D3 on mRNA level, although different mechanisms account for the upregulation of each gene.
Type 1 diabetes (T1D) results from the autoimmune destruction of insulin-producing beta-cells in the pancreas. Recruitment of inflammatory cells is prerequisite to beta-cell-injury. The junctional adhesion molecule (JAM) family proteins JAM-B and JAM–C are involved in polarized leukocyte transendothelial migration and are expressed by vascular endothelial cells of peripheral tissue and high endothelial venules in lympoid organs. Blocking of JAM-C efficiently attenuated cerulean-induced pancreatitis, rheumatoid arthritis or inflammation induced by ischemia and reperfusion in mice. In order to investigate the influence of JAM-C on trafficking and transmigration of antigen-specific, autoaggressive T-cells, we used transgenic mice that express a protein of the lymphocytic choriomeningitis virus (LCMV) as a target autoantigen in the β-cells of the islets of Langerhans under the rat insulin promoter (RIP). Such RIP-LCMV mice turn diabetic after infection with LCMV. We found that upon LCMV-infection JAM-C protein was upregulated around the islets in RIP-LCMV mice. JAM-C expression correlated with islet infiltration and functional beta-cell impairment. Blockade with a neutralizing anti-JAM-C antibody reduced the T1D incidence. However, JAM-C overexpression on endothelial cells did not accelerate diabetes in the RIP-LCMV model. In summary, our data suggest that JAM-C might be involved in the final steps of trafficking and transmigration of antigen-specific autoaggressive T-cells to the islets of Langerhans.
The mitogen-activated protein kinase (MAPK) pathway is the canonical signaling pathway for many receptor tyrosine kinases, such as the Epidermal Growth Factor Receptor. Downstream of the receptors, this pathway involves the activation of a kinase cascade that culminates in a transcriptional response and affects processes, such as cell migration and adhesion. In addition, the strength and duration of the upstream signal also influence the mode of the cellular response that is switched on. Thus, the same components can in principle coordinate opposite responses, such as proliferation and differentiation. In recent years, it has become evident that MAPK signaling is regulated and fine-tuned by proteins that can bind to several MAPK signaling proteins simultaneously and, thereby, affect their function. These so-called MAPK scaffolding proteins are, thus, important coordinators of the signaling response in cells. In this review, we summarize the recent advances in the research on MAPK/extracellular signal-regulated kinase (ERK) pathway scaffolders. We will not only review the well-known members of the family, such as kinase suppressor of Ras (KSR), but also put a special focus on the function of the recently identified or less studied scaffolders, such as fibroblast growth factor receptor substrate 2, flotillin-1 and mitogen-activated protein kinase organizer.
Introduction: We aimed at dissociating the neural correlates of memory disorders in Alzheimer’s disease (AD) and frontotemporal lobar degeneration (FTLD).
Methods: We included patients with AD (n = 19, 11 female, mean age 61 years) and FTLD (n = 11, 5 female, mean age 61 years) in early stages of their diseases. Memory performance was assessed by means of verbal and visual memory subtests from the Wechsler Memory Scale (WMS-R), including forgetting rates. Brain glucose utilization was measured by [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) and brain atrophy by voxel-based morphometry (VBM) of T1-weighted magnetic resonance imaging (MRI) scans. Using a whole brain approach, correlations between test performance and imaging data were computed separately in each dementia group, including a group of control subjects (n = 13, 6 female, mean age 54 years) in both analyses. The three groups did not differ with respect to education and gender.
Results: Patients in both dementia groups generally performed worse than controls, but AD and FTLD patients did not differ from each other in any of the test parameters. However, memory performance was associated with different brain regions in the patient groups, with respect to both hypometabolism and atrophy: Whereas in AD patients test performance was mainly correlated with changes in the parieto-mesial cortex, performance in FTLD patients was correlated with changes in frontal cortical as well as subcortical regions. There were practically no overlapping regions associated with memory disorders in AD and FTLD as revealed by a conjunction analysis.
Conclusion: Memory test performance may not distinguish between both dementia syndromes. In clinical practice, this may lead to misdiagnosis of FTLD patients with poor memory performance. Nevertheless, memory problems are associated with almost completely different neural correlates in both dementia syndromes. Obviously, memory functions are carried out by distributed networks which break down in brain degeneration.