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The sphingolipid sphingosine-1-phosphate (S1P) emerges as an important regulator of immunity, mainly by signaling through a family of five specific G protein-coupled receptors (S1PR1–5). While S1P signaling generally has the potential to affect not only trafficking but also differentiation, activation, and survival of a diverse range of immune cells, the specific outcome depends on the S1P receptor repertoire expressed on a given cell. Among the S1PRs, S1PR4 is specifically abundant in immune cells, suggesting a major role of the S1P/S1PR4 axis in immunity. Recent studies indeed highlight its role in activation of immune cells, differentiation, and, potentially, trafficking. In this review, we summarize the emerging data that support a major role of S1PR4 in modulating immunity in humans and mice and discuss therapeutic implications.
S1P provokes tumor lymphangiogenesis via macrophage-derived mediators such as IL-1β or lipocalin-2
(2017)
A pleiotropic signaling lipid, sphingosine-1-phosphate (S1P), has been implicated in various pathophysiological processes supporting tumor growth and metastasis. However, there are only a few descriptive studies suggesting a role of S1P in tumor lymphangiogenesis, which is critical for tumor growth and dissemination. Corroborating own data, the literature suggests that apoptotic tumor cell-derived S1P alters the phenotype of tumor-associated macrophages (TAMs) to gain protumor functions. However, mechanistically, the role of TAM-induced lymphangiogenesis has only been poorly described, mostly linked to the production of lymphangiogenic factors such as vascular endothelial growth factor C (VEGF-C) and VEGF-D, or transdifferentiation into lymphatic endothelial cells. Recent findings highlight a rather underappreciated role of S1P in tumor lymphangiogenesis, referring to the production of interleukin-1β (IL-1β) and lipocalin-2 (LCN2) by a tumor-promoting macrophage phenotype. In this review, we aim to provide to the readers with the current understanding of the molecular mechanism how apoptotic cell-derived S1P triggers TAMs to promote lymphangiogenesis.
Motivation: Arabidopsis thaliana is a well-established model system for the analysis of the basic physiological and metabolic pathways of plants. Nevertheless, the system is not yet fully understood, although many mechanisms are described, and information for many processes exists. However, the combination and interpretation of the large amount of biological data remain a big challenge, not only because data sets for metabolic paths are still incomplete. Moreover, they are often inconsistent, because they are coming from different experiments of various scales, regarding, for example, accuracy and/or significance. Here, theoretical modeling is powerful to formulate hypotheses for pathways and the dynamics of the metabolism, even if the biological data are incomplete. To develop reliable mathematical models they have to be proven for consistency. This is still a challenging task because many verification techniques fail already for middle-sized models. Consequently, new methods, like decomposition methods or reduction approaches, are developed to circumvent this problem.
Methods: We present a new semi-quantitative mathematical model of the metabolism of Arabidopsis thaliana. We used the Petri net formalism to express the complex reaction system in a mathematically unique manner. To verify the model for correctness and consistency we applied concepts of network decomposition and network reduction such as transition invariants, common transition pairs, and invariant transition pairs.
Results: We formulated the core metabolism of Arabidopsis thaliana based on recent knowledge from literature, including the Calvin cycle, glycolysis and citric acid cycle, glyoxylate cycle, urea cycle, sucrose synthesis, and the starch metabolism. By applying network decomposition and reduction techniques at steady-state conditions, we suggest a straightforward mathematical modeling process. We demonstrate that potential steady-state pathways exist, which provide the fixed carbon to nearly all parts of the network, especially to the citric acid cycle. There is a close cooperation of important metabolic pathways, e.g., the de novo synthesis of uridine-5-monophosphate, the γ-aminobutyric acid shunt, and the urea cycle. The presented approach extends the established methods for a feasible interpretation of biological network models, in particular of large and complex models.
Mit spitzer Feder beschreibt Lucius Burckhardt in seinem Aufsatz "Wer plant die Planung?" die konfligierenden Rationalitäten der am Planungsprozess beteiligten Akteure. Dabei zeigt er auf, wie "das Kräfteparallelogramm zwischen der regierenden Beamtenschaft, der Bauspekulation, der Bürgerschaft und den durch die beschlossenen Maßnahmen betroffenen Leute" (S. 107) die "Übelstände der Stadt" häufig verschlimmbessert. Es fehle ein "strategisches Vorgehen", das "dem Systemcharakter der Stadt angemessen" (S. 113) wäre.
Ebenso wie Pierre Bourdieu ist sein Schüler Loïc Wacquant einer der selten gewordenen Intellektuellen, die ihre Profession, die Soziologie, nutzen um soziale Ungleichheiten und gesellschaftliche Machtverhältnisse nicht nur zu analysieren, sondern auch versuchen, damit auf öffentliche Debatten zu einzuwirken. Daher ist Wacquants Aufsatz nicht nur als eine interessante Diskussion der Frage, ob Bourdieus Werk in der Stadtsoziologie angemessen und korrekt verwendet werde, zu verstehen. Der in dem Text formulierte Appell, Bourdieus Arbeit auch innerhalb der Stadtsoziologie stärker anzuwenden, ist – vor dem Hintergrund zunehmender sozialer Ungleichheit, Armut, Marginalisierung und einem Aufschwung des Rechtspopulismus – eine Forderung nach einer soziologischen Betrachtung dieser Probleme in der Stadt. Was kann nun also das Werk von Pierre Bourdieu zur Analyse der heutigen sozialen Probleme in der Stadt in Deutschland beitragen?
Endogenous AJAP1 associates with the cytoskeleton and attenuates angiogenesis in endothelial cells
(2017)
The adherens junction associated protein 1 (AJAP1, aka shrew-1) is presumably a type-I transmembrane protein localizing and interacting with the E-cadherin-catenin complex. In various tumors, AJAP1 expression is reduced or lost, including hepatocellular and esophageal squamous cell carcinoma, and glial-derived tumors. The aberrant expression of AJAP1 is associated with alterations in cell migration, invasion, increased tumor growth, and tumor vascularization, suggesting AJAP1 as a putative tumor suppressor. We show that AJAP1 attenuates sprouting angiogenesis by reducing endothelial migration and invasion capacities. Further, we show for the first time that endogenous AJAP1 is associated with the microtubule cytoskeleton. This linkage is independent from cell confluency and stable during angiogenic sprouting in vitro. Our work suggests that AJAP1 is a putative negative regulator of angiogenesis, reducing cell migration and invasion by interfering with the microtubule network. Based on our results and those of other authors, we suggest AJAP1 as a novel tumor suppressor and diagnostic marker.
Background: Oral anticoagulation therapy (OAT) is a challenge in general practice, especially for high-risk groups such as the elderly. Insufficient patient knowledge about safety-relevant aspects of OAT is considered to be one of the main reasons for complications. The research question addressed in this manuscript is whether a complex intervention that includes practice-based case management, self-management of OAT and additional patient and practice team education improves patient knowledge about anticoagulation therapy compared to a control group of patients receiving usual care (as a secondary objective of the Primary Care Management for Optimised Antithrombotic Treatment (PICANT) trial).
Methods: The cluster-randomised controlled PICANT trial was conducted in 52 general practices in Germany, between 2012 and 2015. Trial participants were patients with a long-term indication for oral anticoagulation. A questionnaire was used to assess knowledge at baseline, after 12, and after 24 months. The questionnaire consists of 13 items (with a range of 0 to 13 sum-score points) covering topics related to intervention. Differences in the development of patient knowledge between intervention and control groups compared to baseline were assessed for each follow-up by means of linear mixed-effects models.
Results: Seven hundred thirty-six patients were included at baseline, of whom 95.4% continued to participate after 12 months, and 89.3% after 24 months. The average age of patients was 73.5 years (SD 9.4), and they mainly suffered from atrial fibrillation (81.1%). Patients in the intervention and control groups had similar knowledge about oral anticoagulation at baseline (5.6 (SD 2.3) in both groups). After 12 months, the improvement in the level of knowledge (compared to baseline) was significantly larger in the intervention group than in the control group (0.78 (SD 2.5) vs. 0.04 (SD 2.3); p = 0.0009). After 24 months, the difference between both groups was still statistically significant (0.6 (SD 2.6) vs. -0.3 (SD 2.3); p = 0.0001).
Conclusion: Since this intervention was effective, it should be established in general practice as a means of improving patient knowledge about oral anticoagulation.
Trial registration: Current controlled trials ISRCTN41847489; Date of registration: 13/04/2012
Dieser Beitrag geht nun vor allem begrifflich-historischen Aspekten des Zusammenhangs von 'Sicherheit' und 'Unverfügbarkeit' nach, wobei ich historisch und konzeptuell vor allem an 'Sicherheit' interessiert bin. 'Unverfügbarkeit' oder 'Nichtverfügbarkeit' wird unterdessen in weiten Teilen heuristisch gebraucht, zum Zwecke der Zusammenschau bestimmter Phänomene.
Die in diesem Artikel vorgestellten Überlegungen sind das Ergebnis breitflächiger empirischer Untersuchungen von Zeitungen und Zeitschriften aus den USA, Kanada, Großbritannien und Frankreich. Sie rekonstruieren also die Verwendungen des Begriffs in denjenigen Ländern, die sich seit Entstehen des Begriffs als 'westlich' verstanden haben und deren Zugehörigkeit zum 'Westen' kaum je in Frage gestellt worden ist. Es wird also die Binnenperspektive 'des Westens' dargelegt. Da das Anliegen dieses Artikels konzeptionell ist, wird darauf verzichtet, Quellenmaterial zu zitieren, stattdessen nur auf weiterführende Literatur verwiesen, die die Sachverhalte, auf die in der Analyse des Begriffs des Westens Bezug genommen wird, näher erläutern.
Im Folgenden sollen drei Beispiele für Migrationsprozesse skizziert werden, bei denen sich Wanderbewegungen von musikalischen Fachbegriffen und den in diesen verdichteten musikalischen Prozessen mit semantischen Transformationen verbinden. Angesiedelt sind die Beispiele in unterschiedlichen kulturellen Räumen, und sie migrieren zwischen verschiedenen räumlichen Bezugssystemen auf jeweils eigene und besondere Art. Auch unterschiedliche Zeitbereiche werden angesprochen, wenngleich alle drei Fallbeispiele in der Frühen Neuzeit angesiedelt sind.
Objectives: It is known that transition, as a shift of care, marks a vulnerable phase in the adolescents’ lives with an increased risk for non-adherence and allograft failure. Still, the transition process of adolescents and young adults living with a kidney transplant in Germany is not well defined. The present research aims to assess transition-relevant structures for this group of young people. Special attention is paid to the timing of the process.
Setting: In an observational study, we visited 21 departments of paediatric nephrology in Germany. Participants were doctors (n=19), nurses (n=14) and psychosocial staff (n=16) who were responsible for transition in the relevant centres. Structural elements were surveyed using a short questionnaire. The experiential viewpoint was collected by interviews which were transcribedverbatim before thematic analysis was performed.
Results: This study highlights that professionals working within paediatric nephrology in Germany are well aware of the importance of successful transition. Key elements of transitional care are well understood and mutually agreed on. Nonetheless, implementation within daily routine seems challenging, and the absence of written, structured procedures may hamper successful transition.
Conclusions: While professionals aim for an individual timing of transfer based on medical, social, emotional and structural aspects, rigid regulations on transfer age as given by the relevant health authorities add on to the challenge.
Trial registration: number ISRCTN Registry no 22988897; results (phase I) and pre-results (phase II).
Background: Multimorbidity is associated with negative effects both on people’s health and on healthcare systems. A key problem linked to multimorbidity is polypharmacy, which in turn is associated with increased risk of partly preventable adverse effects, including mortality. The Ariadne principles describe a model of care based on a thorough assessment of diseases, treatments (and potential interactions), clinical status, context and preferences of patients with multimorbidity, with the aim of prioritizing and sharing realistic treatment goals that guide an individualized management. The aim of this study is to evaluate the effectiveness of a complex intervention that implements the Ariadne principles in a population of young-old patients with multimorbidity and polypharmacy. The intervention seeks to improve the appropriateness of prescribing in primary care (PC), as measured by the medication appropriateness index (MAI) score at 6 and 12 months, as compared with usual care.
Methods/Design: Design: pragmatic cluster randomized clinical trial. Unit of randomization: family physician (FP). Unit of analysis: patient. Scope: PC health centres in three autonomous communities: Aragon, Madrid, and Andalusia (Spain). Population: patients aged 65–74 years with multimorbidity (≥3 chronic diseases) and polypharmacy (≥5 drugs prescribed in ≥3 months). Sample size: n = 400 (200 per study arm). Intervention: complex intervention based on the implementation of the Ariadne principles with two components: (1) FP training and (2) FP-patient interview. Outcomes: MAI score, health services use, quality of life (Euroqol 5D-5L), pharmacotherapy and adherence to treatment (Morisky-Green, Haynes-Sackett), and clinical and socio-demographic variables. Statistical analysis: primary outcome is the difference in MAI score between T0 and T1 and corresponding 95% confidence interval. Adjustment for confounding factors will be performed by multilevel analysis. All analyses will be carried out in accordance with the intention-to-treat principle.
Discussion: It is essential to provide evidence concerning interventions on PC patients with polypharmacy and multimorbidity, conducted in the context of routine clinical practice, and involving young-old patients with significant potential for preventing negative health outcomes.
Trial registration: Clinicaltrials.gov, NCT02866799
Emergenz und Zukunft
(2017)
Theorien der Emergenz definierten aus rückblickender Perspektive emergente Phänomene als nicht vorhersehbare Qualitätssprünge. Ungeachtet der historischen Betrachtung und der prinzipiellen Unvorhersagbarkeit scheint der Emergenzdiskurs dennoch immer schon Zukunftswissen über Komplexität und spontane Ordnungsbildungsprozesse generiert zu haben. Verschiedene systemtheoretische Ansätze des 20. Jahrhunderts setzten hier an und schufen nicht zuletzt die Voraussetzung für innovative IT-Technologien, dank derer das Emergente, Neue und damit Zukünftige bereits heute die Gegenwart infiltriert. Damit befindet sich auch das Erklärungsmodell der Emergenz im Umbruch. Um diesen nachzuzeichnen, folgt mein Beitrag aus verschiedenen Perspektiven den Bewegungen des Begriffs vom 'Emergentismus' bis hin zur angewandten Forschung im Bereich des 'Emergent Computing'.
Neoadjuvant radiochemotherapy with subsequent total mesorectal excision is the standard of care for locally advanced rectal cancer. While this multimodal strategy has decreased local recurrences rates below 5%, long-term morbidities are considerable in terms of urinary, sexual or bowel functioning. At the same time approximately 10–20% of patients have no evidence of residual tumour in their surgical specimen. Pioneering studies from Brazil have suggested that surgery can safely be omitted in carefully selected patients with a clinical complete response after radiochemotherapy. Although confirmatory studies showed similar results, challenges in terms of optimizing radiochemotherapy for organ-preservation, appropriate selection of patients for non-operative management and the safety of this approach remain. The present review will summarize the current data on organ-preservation in rectal cancer and discuss the challenges that need to be addressed in future trials.
We aimed to prospectively assess changes in chronic stress among young adults transitioning from high school to university or working life. A population-based cohort in Munich and Dresden (Germany) was followed from age 16–18 (2002–2003) to age 20–23 (2007–2009) (n = 1688). Using the Trier Inventory for the Assessment of Chronic Stress, two dimensions of stress at university or work were assessed: work overload and work discontent. In the multiple ordinal generalized estimating equations, socio-demographics, stress outside the workplace, and job history were additionally considered. At follow-up, 52% of the population were university students. Work overload increased statistically significantly from first to second follow-up, while work discontent remained constant at the population level. Students, compared to employees, reported a larger increase in work overload (adjusted odds ratio (OR): 1.33; 95% confidence interval (95% CI): 1.07, 1.67), while work discontent did not differ between the groups. In conclusion, work overload increases when young adults transition from school to university/job life, with university students experiencing the largest increase.
Biosynthetic human insulin and insulin analogues are the mainstay of insulin therapy for both type 1 and type 2 diabetes although access to human insulin at affordable prices remains a global issue. The world is experiencing an exponential rise in the prevalence of diabetes presenting an urgent need to establish effective diabetes therapy in countries burdened by inadequate health care budgets, malnutrition and infectious diseases. Recombinant human insulin has replaced animal insulins and animal-based semisynthetic human insulin thereby available in sufficient quantities and at affordable prices able to provide global access to insulin therapy. In many patients, analog insulins can offer additional clinical benefit, although at a considerably higher price thus severely restricting availability in low income countries. The approval process for recombinant human insulins (i.e. biosimilars) and analogue insulins is highly variable in the developing countries in contrast to Europe and in North America, where it is well established within a strict regulatory framework. This review aims to discuss the future access to human insulin therapy in a global context with an ever increasing burden of diabetes and significant economic implications.
Necroptosis contributes to the pathophysiology of several inflammatory, infectious and degenerative disorders. TNF-induced necroptosis involves activation of the receptor-interacting protein kinases 1 and 3 (RIPK1/3) in a necrosome complex, eventually leading to the phosphorylation and relocation of mixed lineage kinase domain like protein (MLKL). Using a high-content screening of small compounds and FDA-approved drug libraries, we identified the anti-cancer drug Sorafenib tosylate as a potent inhibitor of TNF-dependent necroptosis. Interestingly, Sorafenib has a dual activity spectrum depending on its concentration. In murine and human cell lines it induces cell death, while at lower concentrations it inhibits necroptosis, without affecting NF-κB activation. Pull down experiments with biotinylated Sorafenib show that it binds independently RIPK1, RIPK3 and MLKL. Moreover, it inhibits RIPK1 and RIPK3 kinase activity. In vivo Sorafenib protects against TNF-induced systemic inflammatory response syndrome (SIRS) and renal ischemia–reperfusion injury (IRI). Altogether, we show that Sorafenib can, next to the reported Braf/Mek/Erk and VEGFR pathways, also target the necroptotic pathway and that it can protect in an acute inflammatory RIPK1/3-mediated pathology.
Rho GTPases control fundamental cellular processes and Cdc42 is a well-studied member of the family that controls filopodia formation and cell migration. Although the regulation of Cdc42 activity by nucleotide binding is well documented, the mechanisms driving its proteostasis are not clear. Here, we demonstrate that the highly conserved, RING domain containing E3 ubiquitin ligase XIAP controls the protein stability of Cdc42. XIAP binds to Cdc42 and directly conjugates poly ubiquitin chains to the Lysine 166 of Cdc42 targeting it for proteasomal degradation. Depletion of XIAP led to an increased protein stability and activity of Cdc42 in normal and tumor cells. Consistently, loss of XIAP enhances filopodia formation in a Cdc42-dependent manner and this phenomenon phenocopies EGF stimulation. Further, XIAP depletion promotes lung colonization of tumor cells in mice in a Cdc42-dependent manner. These observations shed molecular insights into ubiquitin-dependent regulation of Cdc42 and that of actin cytoskeleton.
Chemotherapy-induced thrombocytopenia is a common bleeding risk in cancer patients and limits chemotherapy dose and frequency. Recent data from mouse and human platelets revealed that activation of protein kinase A/G (PKA/PKG) not only inhibited thrombin/convulxin-induced platelet activation but also prevented the platelet pro-coagulant state. Here we investigated whether or not PKA/PKG activation could attenuate caspase-dependent apoptosis induced by the anti-cancer drugs ABT-737 (the precursor of navitoclax) and thymoquinone (TQ), thereby potentially limiting chemotherapy-induced thrombocytopenia. This is particularly relevant as activation of cyclic nucleotide signalling in combination chemotherapy is an emerging strategy in cancer treatment. However, PKA/PKG-activation, as monitored by phosphorylation of Vasodilator-stimulated phosphoprotein (VASP), did not block caspase-3-dependent platelet apoptosis induced by the compounds. In contrast, both substances induced PKA activation themselves and PKA activation correlated with platelet inhibition and apoptosis. Surprisingly, ABT-737- and TQ-induced VASP-phosphorylation was independent of cAMP levels and neither cyclases nor phosphatases were affected by the drugs. In contrast, however, ABT-737- and TQ-induced PKA activation was blocked by caspase-3 inhibitors. In conclusion, we show that ABT-737 and TQ activate PKA in a caspase-3-dependent manner, which correlates with platelet inhibition and apoptosis and therefore potentially contributes to the bleeding risk in chemotherapy patients.
Biomaterials are widely used in guided bone regeneration (GBR) and guided tissue regeneration (GTR). After application, there is an interaction between the host immune system and the implanted biomaterial, leading to a biomaterial-specific cellular reaction. The present review focuses on cellular reactions to numerous biomaterials in vivo with consideration of different implantation models and microenvironments in different species, such as subcutaneous implantation in mice and rats, a muscle model in goats and a femur model in rabbits. Additionally, cellular reactions to different biomaterials in various clinical indications within the oro-maxillofacial surgical field were considered. Two types of cellular reactions were observed. There was a physiological reaction with the induction of only mononuclear cells and a pathological reaction with the induction of multinucleated giant cells (MNGCs). Attention was directed to the frequently observed MNGCs and consequences of their appearance within the implantation region. MNGCs have different subtypes. Therefore, the present review addresses the different morphological phenotypes observed within the biomaterial implantation bed and discusses the critical role of MNGCs, their subtypes and their precursors as well as comparing the characteristics and differences between biomaterial-related MNGCs and osteoclasts. Polymeric biomaterials that only induced mononuclear cells underwent integration and maintained their integrity, while polymeric biomaterials that induced MNGCs underwent disintegration with material breakdown and loss of integrity. Hence, there is a question regarding whether our attention should be directed to alternative biological concepts, in combination with biomaterials that induce a physiological mononuclear cellular reaction to optimize biomaterial-based tissue regeneration.
Die folgende Darstellung argumentiert nicht mit Blick auf eine Metahistorik im Koselleck'schen Sinn, sondern beschränkt sich auf die Nachzeichnung einer kurzen Debatte, die unmittelbar an der Wende zum 19. Jahrhundert über die Bedeutung und den angemessenen Gebrauch von 'ahnen' und 'ahnden' geführt wurde. Genauer in den Blick genommen werden drei Fußnoten, in denen Johann Gottfried Herder und Immanuel Kant ihre Einschätzungen zur Gleichheit oder Ungleichheit der Wörter austauschten. Die Passagen entstammen Texten der Jahre 1797 bis 1799 - zweien von Herder, einem vom Kant - die auch sonst einschlägige Positionsbestimmungen zu Problemen der Zukunftserkenntnis vornehmen.
Die Frage ist, ob Blumenbergs explizite Überlegungen zum Phänomen der Epochenschwelle - vor allem in der 'Legitimität der Neuzeit' - sich auch in seinen anderen begriffs- und metapherngeschichtlichen Studien niederschlagen bzw. in welchem Verhältnis beide Theorieelemente zueinander stehen. Dieser Frage widmen sich die folgenden Anmerkungen. Sie versuchen beide Bereiche in Blumenbergs Denken aufeinander zu beziehen, ihre Kohärenz zu untersuchen und sie in eine produktive Spannung miteinander zu bringen.
Die folgenden Ausführungen am Beispiel von Zukunft und Zukünftigkeit setzen in dem Areal an, von dem Blumenberg eine ganze Reihe von Begrifflichkeiten und Denkfiguren entlehnt und historisch seinen Ausgang genommen hat, der Phänomenologie Husserls. Im Mittelpunkt steht dabei die für sämtliche Diskussionen um Zukunft und Zukünftigkeit zentrale Denkfigur der Protention. Sie wird in ihren begrifflichen Zusammenhängen, Problemen und Dimensionen entwickelt (1-4). Sodann wird Blumenbergs Kritik der Futurologie dargestellt (5). Mit dem Konzept der Prävention soll schließlich der von der Protention abgeleitete Modus thematisiert werden, in dem metaphorologische und anthropologische Aspekte zusammengeschlossen sind (6). Abschließend wird die Konzeption der Prävention in den Kontext der philosophischen Anthropologie Gehlens und der Existenzialanalyse Heideggers gestellt (7).
Funktionsverbgefüge im Deutschen und Türkischen : eine Analyse in ausgewählten Zeitungstexten
(2017)
Der vorliegende Artikel beschäftigt sich mit der Untersuchung von Funktionsverbgefügen (FVG) in deutschen und türkischen Zeitungstexten im Rahmen der kontrastiven Linguistik. Die FVG, welche aus einem Funktionsverb und einem Substantiv bestehen, werden im Deutschen als eine grammatische Kategorie abgehandelt. Die für deutsche Sprache entwickelten Kriterien werden ins Türkische adaptiert. Es wurde festgestellt, dass FVG bzw. die Substantiv-Verb Verbindungen in beiden Sprachen hinsichtlich der morphologischen, syntaktischen und semantischen Kriterien über gemeinsame Merkmale verfügen. Da diese Strukturen meistens in der Schriftsprache verwendet werden, werden sie in dieser Arbeit in Zeitungstexten untersucht. Am Ende dieser Untersuchung wurde festgestellt, dass die betreffende Struktur in beiden Sprachen Anwendung findet und ähnliche Merkmale hat. Auch stellte sich heraus, dass die präpositionalen Strukturen im Deutschen mehr Anwendung finden, während im Türkischen Substantiv im Akkusativ mehr gebraucht wird.
Ziel der vorliegenden Arbeit ist die Vorstellung einer Übersicht über die Moose und Moosgesellschaften der Kalkrasen sowie der angrenzenden Vegetationstypen im Muschelkalkgebiet des unteren Unstruttales in der Umgebung von Zscheiplitz zwischen Laucha und Freyburg/Unstrut. Bedeutungsvoll sind in einem Kalksteinbruch, in verschiedenen Trocken- und Halbtrockenrasen sowie Xerothermgebüschen die epilithischen, photophytischen Assoziationen Orthotricho anomali-Grimmietum pulvinatae, Grimmietum orbicularis, das seltene Grimmietum tergestinae, die sciophytischen Gesellschaften Homomallietum incurvati und die Homalothecium sericeum-Gesellschaft. Auf Kalkböden gedeihen häufig das Tortelletum inclinatae, vereinzelt das Barbuletum convolutae, in den Fugen der Kalkbänke das Weissietum crispatae und Aloinetum rigidae mit Aloina obliquifolia. Auf der Borke lebender Laubgehölze wachsen vereinzelt das Orthotrichetum fallacis, Syntrichio latifoliae-Leskeetum polycarpae, lokal das Ulotetum crispae, Syntrichietum pulvinatae und Orthotrichetum pallentis. Alle Gesellschaften sind durch zahlreiche Vegetationsaufnahmen in 11 Tabellen dargestellt. Insgesamt wurden 21 Moosgesellschaften und 104 Moosarten (7 Lebermoose, 97 Laubmoose) nachgewiesen. Die Diskussion betrifft die bryogeographische Situation in der Umgebung von Zscheiplitz sowie die Lebensformen, Lebensstrategien und Reproduktionsstrategien der Moose und Moosgesellschaften.
Von dreizehn Phytoflagellaten, davon zehn Euglenophyta, die aus der „Hohe Garbe“ im Naturschutzgebiet „Aland-Elbe-Niederung“ beschrieben und dokumentiert werden, sind elf Arten neu für Sachsen-Anhalt. Phacus warszewiczii wird in vorliegender Publikation erstmals nach Funden aus Deutschland abgebildet.
Buchbesprechung
(2017)
Die Autoren setzten mit der Herausgabe ihrer umfangreichen Übersicht über die Florenwerke Deutschlands eine lange Tradition fort, bekanntes Wissen übersichtlich aufzubereiten, um es so komfortabel nutzbar zu machen. Gelegentlich wird es darüber hinaus sicher ein Aha-Erlebnis geben, dass es über dieses oder jenes Gebiet überhaupt schon ein floristisches Werk gibt.
Aktuell bekannte Vorkommen von A. adiantum-nigrum L., A. ceterach L., A. ruta-muraria L., A. scolopendrium L., A. septentrionale (L.) Hoffm., A. trichomanes L. und A. viride W. Huds. im Mitteldeutschen Trockengebiet um Halle werden mitgeteilt. Erstmalig wurden Vorkommen von Asplenium trichomanes auf Unterarten untersucht und die Ergebnisse vorgestellt. Auch der intraspezifische Bastard A. trichomanes nothosubsp. lovisianum S. Jess. wurde nachgewiesen.
Eine bisher nicht erkannte heimische Scharbockskrautart, Ficaria calthifolia Rchb., wurde im Elbetal bei Pretzsch neu für Sachsen-Anhalt nachgewiesen. Da die Art nicht über Mechanismen zur aktiven Fernausbreitung verfügt, sondern räumlich-zeitlich kleine Nischen besiedelt (CSR-Strategie), ist Habitatkontinuität wichtig. In diesem Zusammenhang wird die Bedeutung von historisch altem Grünland diskutiert.
Die Fundortdaten der im Altmarkkreis Salzwedel nachgewiesenen Verwilderungen von Amelanchier alnifolia, A. lamarckii und A. spicata werden mitgeteilt. Angaben zu den Standortverhältnissen, zur Begleitflora und zum Populationsumfang ergänzen die Ausführungen. Außerdem wird auf wesentliche Unterscheidungsmerkmale der drei Arten eingegangen.
Pulmonaria obscura ist die einzige Art des Genus Pulmonaria, die im Raum Salzwedel noch autochthone Vorkommen aufzuweisen hat. Hinzu kommen einige Verwilderungen der auch als Zierpflanze gezogenen P. officinalis s. str. Von beiden Arten werden die aktuellen Nachweisdaten mitgeteilt. Auf die Differenzierung des P. officinalis agg. und die Trennung von weiteren kultivierten Sippen wird eingegangen. Außerdem werden die historischen Aufzeichnungen über Vorkommen von P. angustifolia bei Salzwedel dargestellt. Angaben zur Bedeutung von P. officinalis s. str. in der Volksheilkunde vervollständigen die Ausführungen.
Tumor-associated macrophages, angiogenesis, and tumor cell migration in oral squamous cell carcinoma
(2017)
Objective: To investigate the relationship between tumor-associated macrophages (TAMs), neovascularization, and tumor cell migration in oral squamous cell carcinoma (OSCC) of an African subpopulation.
Materials and Methods: Twenty OSCC paraffin blocks underwent immunohistochemistry to TAM1 (CCR7), TAM2 (CD206), Twist, E-cadherin, N-cadherin, and CD34. The relative percentage of CCR7 + and CD206 + cells to overall immune cell population was calculated for three high power fields and an average was taken. TAM-related microvessel density (MVD) was determined as the mean of the three recorded values. Cases that had no CD34 + vessels adjacent to the TAMs region were regarded as having an MVD score of 0.
Results: Ten cases (50%) expressed greater CCR7 activity than CD206, seven cases (35%) expressed approximately equal activity of CCR7 and CD206, while three cases (15%) expressed greater activity of CD206 than CCR7. Twist expression was strong in some cases with strong N-cadherin and weak E-cadherin, but the expression of Twist was not consistently high in all cases that expressed strong N-cadherin and weak E-cadherin.
Conclusions: TAMs distribution suggested antitumor activity and the potential for tumor metastasis was only partly due to Twist-mediated epithelial–mesenchymal transition.
Androgen receptor deregulation drives bromodomain-mediated chromatin alterations in prostate cancer
(2017)
Global changes in chromatin accessibility may drive cancer progression by reprogramming transcription factor (TF) binding. In addition, histone acetylation readers such as bromodomain-containing protein 4 (BRD4) have been shown to associate with these TFs and contribute to aggressive cancers including prostate cancer (PC). Here, we show that chromatin accessibility defines castration-resistant prostate cancer (CRPC). We show that the deregulation of androgen receptor (AR) expression is a driver of chromatin relaxation and that AR/androgen-regulated bromodomain-containing proteins (BRDs) mediate this effect. We also report that BRDs are overexpressed in CRPCs and that ATAD2 and BRD2 have prognostic value. Finally, we developed gene stratification signature (BROMO-10) for bromodomain response and PC prognostication, to inform current and future trials with drugs targeting these processes. Our findings provide a compelling rational for combination therapy targeting bromodomains in selected patients in which BRD-mediated TF binding is enhanced or modified as cancer progresses.
NADPH oxidases of the Nox family are important enzymatic sources of reactive oxygen species (ROS) in the cardiovascular system. Of the 7 members of the Nox family, at least three depend for their activation on specific cytosolic proteins. These are p47phox and its homologue NoxO1 and p67phox and its homologue NoxA1. Also the Rho-GTPase Rac is important but as this protein has many additional functions, it will not be covered here. The Nox1 enzyme is preferentially activated by the combination of NoxO1 with NoxA1, whereas Nox2 gains highest activity with p47phox together with p67phox. As p47phox, different to NoxO1 contains an auto inhibitory region it has to be phosphorylated prior to complex formation. In the cardio-vascular system, all cytosolic Nox proteins are expressed but the evidence for their contribution to ROS production is not well established. Most data have been collected for p47phox, whereas NoxA1 has basically not yet been studied. In this article the specific aspects of cytosolic Nox proteins in the cardiovascular system with respect to Nox activation, their expression and their importance will be reviewed. Finally, it will be discussed whether cytosolic Nox proteins are suitable pharmacological targets to tamper with vascular ROS production.
Background: In this study we evaluated the interactions of human adipose tissue-derived stem cells (ADSCs) and different human breast cancer cell lines (BRCAs) with regard to the safety of cell-assisted lipotransfers for breast reconstruction and a thereby unintended co-localization of ADSCs and BRCAs.
Methods: ADSCs were co-cultured with five different human BRCAs (MCF-7, MDA-MB-231, SK-BR-3, ZR-75-30, and EVSA-T) and primary BRCAs from one patient in a transwell system, and cell-cell-interactions were analyzed by assessing doubling time, migration and invasion, angiogenesis, quantitative real-time polymerase chain reaction (PCR) of more than 300 tumor-associated genes, and multiplex protein assays of 20 chemokines and growth factors and eight matrix metalloproteinases (MMPs). Results of co-culture were compared to those of the respective monoculture.
Results: Quantitative real-time PCR revealed remarkable changes in the expression of multiple tumor-associated genes in co-culture compared to monocultures of both ADSCs and BRCAs. Concomitantly, the concentration of several tumor-associated proteins, such as cytokines and MMPs, were strongly increased in co-culture. Furthermore, exclusively in co-culture with ADSCs, the different BRCAs were exposed to several important tumor-modulating proteins, such as CCL2, HGF, or interleukins.
Co-culture did not significantly affect cellular proliferation of either ADSCs or BRCAs (p > 0.05). The migration of MCF-7 and MDA-MB-231 BRCAs was significantly increased in co-culture with ADSCs by a mean of 11% and 23%, respectively (p = 0.04 and 0.012), as well as that of ADSCs in co-culture with MDA-MB-231, ZR-75-30, and EVSA-T (+11–15%, p = 0.035–0.045). Co-culture with MDA-MB-231, SK-BR-3, and EVSA-T BRCAs significantly increased the invasive behavior of ADSCs by a mean of 24–41% (p = 0.014–0.039). There were no significant differences in the in vitro invasive properties of BRCAs in co-culture compared to monoculture. An in vitro angiogenesis assay revealed an increased tube formation of conditioned media from co-cultured BRCAs and ADSCs compared to the respective monocultures.
Conclusion: This study further elucidates the possible interactions of primary human ADSCs with human BRCAs, pointing towards a potential increased oncological risk which should not be neglected when considering a clinical use of cell-assisted lipoaspirates in breast reconstruction.
Background: Denosumab treatment for up to 8 years in the FREEDOM study and Extension was associated with low fracture incidence. It was not clear whether subjects who discontinued during the study conduct had a higher risk of fracture than those who remained enrolled, thereby underestimating the true fracture risk for the entire trial cohort. Thus, we explored the influence of early withdrawals on nonvertebral fracture incidence during the Extension study.
Methods: To understand the potential effect of depletion of susceptible subjects on fracture incidence, we first evaluated subject characteristics in patients who were enrolled in the Extension vs those who were not. We subsequently employed a Kaplan-Meier multiple imputation (KMMI) approach to consider subjects who discontinued as if they remained enrolled with a 0%, 20%, 50%, and 100% increase in fracture risk compared with participants remaining on study.
Results: Extension enrollees were generally similar to nonparticipants in median age (71.9 and 73.1 years, respectively), mean total hip bone mineral density T-score (–1.9 and –2.0, respectively), and probability of fracture risk by Fracture Risk Assessment Tool (FRAX®) at FREEDOM baseline (16.9% and 17.7% for major osteoporotic fracture and 6.7% and 7.4% for hip fracture, respectively). When we assumed a doubled fracture risk (100% increase) after discontinuation in KMMI analyses, nonvertebral fracture rate estimates were only marginally higher than the observed rates for both the crossover group (10.32% vs 9.16%, respectively) and the long-term group (7.63% vs 6.63%, respectively).
Conclusion: The observation of continued denosumab efficacy over 8 years of treatment was robust and does not seem to be explained by depletion of susceptible subjects.
Trial registration: ClincalTrials.gov registration number NCT00523341; registered August 30, 2007
Dysfunction of the NO/sGC/cGMP signaling pathway has been implicated in the pathogenesis of pulmonary hypertension (PH). Therefore, agents stimulating cGMP synthesis via sGC are important therapeutic options for treatment of PH patients. An unwanted effect of this novel class of drugs is their systemic hypotensive effect. We tested the hypothesis that aerosolized intra-tracheal delivery of the sGC stimulator BAY41-8543 could diminish its systemic vasodilating effect.
Pharmacodynamics and -kinetics of BAY41-8543 after single intra-tracheal delivery was tested in healthy rats. Four weeks after a single injection of monocrotaline (MCT, 60 mg/kg s.c.), rats were randomized to a two-week treatment with either placebo, BAY 41-8543 (10 mg/kg per os (PO)) or intra-tracheal (IT) instillation (3 mg/kg or 1 mg/kg).
Circulating concentrations of the drug 10 mg/kg PO and 3 mg/kg IT were comparable. BAY 41-8543 was detected in the lung tissue and broncho-alveolar fluid after IT delivery at higher concentrations than after PO administration. Systemic arterial pressure transiently decreased after oral BAY 41-8543 and was unaffected by intratracheal instillation of the drug. PO 10 mg/kg and IT 3 mg/kg regimens partially reversed pulmonary hypertension and improved heart function in MCT-injected rats. Minor efficacy was noted in rats treated IT with 1 mg/kg. The degree of pulmonary vascular remodeling was largely reversed in all treatment groups.
Intratracheal administration of BAY 41-8543 reverses PAH and vascular structural remodeling in MCT-treated rats. Local lung delivery is not associated with systemic blood pressure lowering and represents thus a further development of PH treatment with sGC stimulators.
T lymphocytes against tumor-specific mutated neoantigens can induce tumor regression. Also, the size of the immunogenic cancer mutanome is supposed to correlate with the clinical efficacy of checkpoint inhibition. Herein, we studied the susceptibility of tumor cell lines from lymph node metastases occurring in a melanoma patient over several years towards blood-derived, neoantigen-specific CD8+ T cells. In contrast to a cell line established during early stage III disease, all cell lines generated at later time points from stage IV metastases exhibited partial or complete loss of HLA class I expression. Whole exome and transcriptome sequencing of the four tumor lines and a germline control were applied to identify expressed somatic single nucleotide substitutions (SNS), insertions and deletions (indels). Candidate peptides encoded by these variants and predicted to bind to the patient’s HLA class I alleles were synthesized and tested for recognition by autologous mixed lymphocyte-tumor cell cultures (MLTCs). Peptides from four mutated proteins, HERPUD1G161S, INSIG1S238F, MMS22LS437F and PRDM10S1050F, were recognized by MLTC responders and MLTC-derived T cell clones restricted by HLA-A*24:02 or HLA-B*15:01. Intracellular peptide processing was verified with transfectants. All four neoantigens could only be targeted on the cell line generated during early stage III disease. HLA loss variants of any kind were uniformly resistant. These findings corroborate that, although neoantigens represent attractive therapeutic targets, they also contribute to the process of cancer immunoediting as a serious limitation to specific T cell immunotherapy.
Despite advances in myocardial reperfusion therapies, acute myocardial ischaemia/reperfusion injury and consequent ischaemic heart failure represent the number one cause of morbidity and mortality in industrialized societies. Although different therapeutic interventions have been shown beneficial in preclinical settings, an effective cardioprotective or regenerative therapy has yet to be successfully introduced in the clinical arena. Given the complex pathophysiology of the ischaemic heart, large scale, unbiased, global approaches capable of identifying multiple branches of the signalling networks activated in the ischaemic/reperfused heart might be more successful in the search for novel diagnostic or therapeutic targets. High-throughput techniques allow high-resolution, genome-wide investigation of genetic variants, epigenetic modifications, and associated gene expression profiles. Platforms such as proteomics and metabolomics (not described here in detail) also offer simultaneous readouts of hundreds of proteins and metabolites. Isolated omics analyses usually provide Big Data requiring large data storage, advanced computational resources and complex bioinformatics tools. The possibility of integrating different omics approaches gives new hope to better understand the molecular circuitry activated by myocardial ischaemia, putting it in the context of the human ‘diseasome’. Since modifications of cardiac gene expression have been consistently linked to pathophysiology of the ischaemic heart, the integration of epigenomic and transcriptomic data seems a promising approach to identify crucial disease networks. Thus, the scope of this Position Paper will be to highlight potentials and limitations of these approaches, and to provide recommendations to optimize the search for novel diagnostic or therapeutic targets for acute ischaemia/reperfusion injury and ischaemic heart failure in the post-genomic era.
The CRISPR/Cas9 prokaryotic adaptive immune system and its swift repurposing for genome editing enables modification of any prespecified genomic sequence with unprecedented accuracy and efficiency, including targeted gene repair. We used the CRISPR/Cas9 system for targeted repair of patient-specific point mutations in the Cytochrome b-245 heavy chain gene (CYBB), whose inactivation causes chronic granulomatous disease (XCGD)—a life-threatening immunodeficiency disorder characterized by the inability of neutrophils and macrophages to produce microbicidal reactive oxygen species (ROS). We show that frameshift mutations can be effectively repaired in hematopoietic cells by non-integrating lentiviral vectors carrying RNA-guided Cas9 endonucleases (RGNs). Because about 25% of most inherited blood disorders are caused by frameshift mutations, our results suggest that up to a quarter of all patients suffering from monogenic blood disorders could benefit from gene therapy employing personalized, donor template-free RGNs.
Purpose: Due to the demographic change morbidity raises the demand for medical hospital services as well as a need for medical specialization, while economic and human resources are diminishing. Unlike other industries hospitals do not have sufficient data and adequate models to relate growing demands and increasing performance to growth in staff capacity and to increase in staff competences.
Method: Based on huge medical data sample covering the years from 2010 to 2014 with more than 150,000 operations of the Department for Anesthesiology at the University Hospital Muenster, Germany, comparisons are drawn between the development of medical services and the development of personnel capacity and expertise.
Results: The numbers of surgical operations increased by 21% and "skin incision to closure" time by 17%. Simultaneously, personnel capacity grew by 16% largely resting upon recruiting first-time employees. Expertise measured as "years of professional experience" dwindled from 10 years to 5.4 years on average and staff turnover accelerated.
Conclusion: Static benchmark data collected at fixed reference dates do not sufficiently reflect the nexus between capacity and competence and do not reflect the dynamic changes in a hospital’s requirements for expertise and specialization, at all. Staff turnover leads to a loss of experience, which jeopardizes patient safety and hampers medical specialization. In consequence of the dramatic shortage of medical specialists, drop-off rates must be reduced and retention rates must be increased. To that end, working conditions need to be fundamentally converted for a multigeneration, multicultural, and increasingly female workforce.
In the later stages of addiction, automatized processes play a prominent role in guiding drug-seeking and drug-taking behavior. However, little is known about the neural correlates of automatized drug-taking skills and drug-related action knowledge in humans. We employed functional magnetic resonance imaging (fMRI) while smokers and non-smokers performed an orientation affordance task, where compatibility between the hand used for a behavioral response and the spatial orientation of a priming stimulus leads to shorter reaction times resulting from activation of the corresponding motor representations. While non-smokers exhibited this behavioral effect only for control objects, smokers showed the affordance effect for both control and smoking-related objects. Furthermore, smokers exhibited reduced fMRI activation for smoking-related as compared to control objects for compatible stimulus-response pairings in a sensorimotor brain network consisting of the right primary motor cortex, supplementary motor area, middle occipital gyrus, left fusiform gyrus and bilateral cingulate gyrus. In the incompatible condition, we found higher fMRI activation in smokers for smoking-related as compared to control objects in the right primary motor cortex, cingulate gyrus, and left fusiform gyrus. This suggests that the activation and performance of deeply embedded, automatized drug-taking schemata employ less brain resources. This might reduce the threshold for relapsing in individuals trying to abstain from smoking. In contrast, the interruption or modification of already triggered automatized action representations require increased neural resources.
Na+/H+ antiporters are located in the cytoplasmic and intracellular membranes and play crucial roles in regulating intracellular pH, Na+, and volume. The NhaA antiporter of Escherichia coli is the best studied member of the Na+/H+ exchanger family and a model system for all related Na+/H+ exchangers, including eukaryotic representatives. Several amino acid residues are important for the transport activity of NhaA, including Lys-300, a residue that has recently been proposed to carry one of the two H+ ions that NhaA exchanges for one Na+ ion during one transport cycle. Here, we sought to characterize the effects of mutating Lys-300 of NhaA to amino acid residues containing side chains of different polarity and length (i.e. Ala, Arg, Cys, His, Glu, and Leu) on transporter stability and function. Salt resistance assays, acridine-orange fluorescence dequenching, solid supported membrane-based electrophysiology, and differential scanning fluorometry were used to characterize Na+ and H+ transport, charge translocation, and thermal stability of the different variants. These studies revealed that NhaA could still perform electrogenic Na+/H+ exchange even in the absence of a protonatable residue at the Lys-300 position. However, all mutants displayed lower thermal stability and reduced ion transport activity compared with the wild-type enzyme, indicating the critical importance of Lys-300 for optimal NhaA structural stability and function. On the basis of these experimental data, we propose a tentative mechanism integrating the functional and structural role of Lys-300.
Objective: Trauma patients (TP) frequently develop an imbalanced immune response that often causes infectious postinjury complications. Monocytes show a diminished capability of both producing proinflammatory cytokines and antigen presentation after trauma. TLR2, TLR4, and TLR9 recognize pathogens and subsequently activate monocytes. While there are conflictive data about TLR2 and TLR4 expression after trauma, no studies about the expression of TLR2, TLR4, TLR9, and HLA-DR on monocytes from TP after their secondary ex vivo-in vitro “hit” have been reported.
Methods/Results: Ex vivo-in vitro lipopolysaccharide- (LPS-) stimulated blood from TP showed diminished interleukin- (IL-) 1β-release in TP for five postinjury days compared to healthy volunteers (HV). The recovery was observed at day 5. In parallel, monocytes from TP showed an impaired capability of TLR2, TLR4, and TLR9 expression after secondary stimulation compared to HV, while the measurement of unstimulated samples showed significant reduction of TLR4 and TLR9 at ED. Furthermore, HLA-DR decreased after trauma and was even more profound by stimulation of monocytes. Ratio of monocytes to leukocytes was significantly increased at days 6 and 7 after trauma compared to HV.
Conclusion: Impaired expression of TLRs and HLA-DR in acute inflammatory conditions may be responsible for the well-described monocyte paralysis after severe trauma.
Sphingolipids are characterized by a broad range of bioactive properties. Particularly, the development of insulin resistance, a major pathophysiological hallmark of Type 2 Diabetes mellitus (T2D), has been linked to ceramide signaling. Since vitamin D supplementation may slow down T2D progression by improving glucose concentrations and insulin sensitivity, we investigated whether vitamin D supplementation impacts on plasma sphingolipid levels in T2D patients. Thus, plasma samples of 59 patients with non-insulin-requiring T2D from a placebo-controlled, randomized, and double-blind study were retrospectively analyzed. Once per week, patients received either 20 drops of Vigantol oil, corresponding to a daily dose of 1904 IU/d vitamin D (verum: n = 31), or a placebo oil consisting of medium chain triglycerides (placebo: n = 28). Blood samples were taken from all of the participants at three different time points: 1) at the beginning of the study (baseline), 2) after 6 months supplementation, and 3) after an additional 6 months of follow-up. Plasma sphingolipids were measured by high-performance liquid chromatography tandem mass spectrometry. At baseline and 6 months follow-up, no significant differences in plasma sphingolipid species were detected between the placebo and verum groups. After 6 months, vitamin D supplementation significantly enhanced plasma C18dihydroceramide (dhCer; N-stearoyl-sphinganine (d18:0/18:0)) and C18ceramide (Cer; N-stearoyl-sphingosine (d18:1/18:0)) levels were observed in the verum group compared to the placebo group. This was accompanied by significantly higher 25-hydroxyvitamin D3 (25(OH)D3) blood levels in patients receiving vitamin D compared to the placebo group. Taken together, vitamin D supplementation induced changes of the C18 chain-length-specific dhCer and Cer plasma levels in patients with T2D. The regulation of sphingolipid signaling by vitamin D may thus unravel a novel mechanism by which vitamin D can influence glucose utilization and insulin action. Whether this acts favorably or unfavorably for the progression of T2D needs to be clarified.
Background: Signal transduction pathways are important cellular processes to maintain the cell’s integrity. Their imbalance can cause severe pathologies. As signal transduction pathways feature complex regulations, they form intertwined networks. Mathematical models aim to capture their regulatory logic and allow an unbiased analysis of robustness and vulnerability of the signaling network. Pathway detection is yet a challenge for the analysis of signaling networks in the field of systems biology. A rigorous mathematical formalism is lacking to identify all possible signal flows in a network model.
Results: In this paper, we introduce the concept of Manatee invariants for the analysis of signal transduction networks. We present an algorithm for the characterization of the combinatorial diversity of signal flows, e.g., from signal reception to cellular response. We demonstrate the concept for a small model of the TNFR1-mediated NF- κB signaling pathway. Manatee invariants reveal all possible signal flows in the network. Further, we show the application of Manatee invariants for in silico knockout experiments. Here, we illustrate the biological relevance of the concept.
Conclusions: The proposed mathematical framework reveals the entire variety of signal flows in models of signaling systems, including cyclic regulations. Thereby, Manatee invariants allow for the analysis of robustness and vulnerability of signaling networks. The application to further analyses such as for in silico knockout was shown. The new framework of Manatee invariants contributes to an advanced examination of signaling systems.