PubMed Central (PMC3 - NLM DTD)
(2,081,148 recursos)
Archive of life sciences journal literature at the U.S. National Institutes of Health (NIH), developed and managed by NIH's National Center for Biotechnology Information (NCBI) in the National Library of Medicine (NLM).
44.
Targeting focal adhesions:Helicobacter pylori-host communication in cell migration - Schneider, Sabine; Weydig, Christiane; Wessler, Silja
Highly dynamic integrin-based focal adhesions provide an important structural basis for anchoring the cellular actin cytoskeleton to the surrounding extracellular matrix. The human pathogen Helicobacter pylori (H. pylori) directly targets integrins with drastic consequences on the epithelial cell morphology and migration, which might contribute to the disruption of the gastric epithelium in vivo. In this review, we summarize the recent findings concerning the complex mechanism through which H. pylori interferes with host integrin signaling thereby deregulating focal adhesions and the actin cytoskeleton of motile epithelial cells.
45.
Signal transduction around thymic stromal lymphopoietin (TSLP) in atopic asthma - Sebastian, Katrin; Borowski, Andreas; Kuepper, Michael; Friedrich, Karlheinz
Thymic stromal lymphopoietin (TSLP), a novel interleukin-7-like cytokine, triggers dendritic cell-mediated inflammatory responses ultimately executed by T helper cells of the Th2 subtype. TSLP emerged as a central player in the development of allergic symptoms, especially in the airways, and is a prime regulatory cytokine at the interface of virus- or antigen-exposed epithelial cells and dendritic cells (DCs). DCs activated by epithelium-derived TSLP can promote naïve CD4+ T cells to adopt a Th2 phenotype, which in turn recruite eosinophilic and basophilic granulocytes as well as mast cells into the airway mucosa. These different cells secrete inflammatory cytokines and chemokines operative...
47.
Cytoplasmic signaling in the control of mitochondrial uproar? - Hermann, Martin; Kuznetsov, Andrey; Maglione, Manuel; Smigelskaite, Julija; Margreiter, Raimund; Troppmair, Jakob
The concept of a pre-emptive strike as a good means to prevent greater harm may be frequently over-stressed in daily life. However, biological systems in a homeostatic balance are prepared to withstand a certain degree of hostile fire by rather passive means. This also applies to the maintenance of cell survival, where a plethora of protective proteins provide safeguard against erroneous activation of death pathways. Apart from these mechanisms active processes are also essential for the maintenance of cellular homeostasis, commonly referred to as survival signaling. Frequently their targets may be mitochondrial, assuring organelle integrity, which is essential for continued...
48.
The small GTPase RhoH is an atypical regulator of haematopoietic cells - Fueller, Florian; Kubatzky, Katharina F
Rho GTPases are a distinct subfamily of the superfamily of Ras GTPases. The best-characterised members are RhoA, Rac and Cdc42 that regulate many diverse actions such as actin cytoskeleton reorganisation, adhesion, motility as well as cell proliferation, differentiation and gene transcription. Among the 20 members of that family, only Rac2 and RhoH show an expression restricted to the haematopoietic lineage.
49.
Signal transduction in cells of the immune system in microgravity - Ullrich, Oliver; Huber, Kathrin; Lang, Kerstin
Life on Earth developed in the presence and under the constant influence of gravity. Gravity has been present during the entire evolution, from the first organic molecule to mammals and humans. Modern research revealed clearly that gravity is important, probably indispensable for the function of living systems, from unicellular organisms to men. Thus, gravity research is no more or less a fundamental question about the conditions of life on Earth. Since the first space missions and supported thereafter by a multitude of space and ground-based experiments, it is well known that immune cell function is severely suppressed in microgravity, which...
52.
Extravasation of leukocytes in comparison to tumor cells - Strell, Carina; Entschladen, Frank
The multi-step process of the emigration of cells from the blood stream through the vascular endothelium into the tissue has been termed extravasation. The extravasation of leukocytes is fairly well characterized down to the molecular level, and has been reviewed in several aspects. Comparatively little is known about the extravasation of tumor cells, which is part of the hematogenic metastasis formation. Although the steps of the process are basically the same in leukocytes and tumor cells, i.e. rolling, adhesion, transmigration (diapedesis), the molecules that are involved are different. A further important difference is that leukocyte interaction with the endothelium changes...
53.
Signal Transduction in the Footsteps of Goethe and Schiller - Friedrich, Karlheinz; Lindquist, Jonathan A; Entschladen, Frank; Serfling, Edgar; Thiel, Gerald; Kieser, Arnd; Giehl, Klaudia; Ehrhardt, Christina; Feller, Stephan M; Ullrich, Oliver; Schaper, Fred; Janssen, Ottmar; Hass, Ralf
The historical town of Weimar in Thuringia, the "green heart of Germany" was the sphere of Goethe and Schiller, the two most famous representatives of German literature's classic era. Not yet entirely as influential as those two cultural icons, the Signal Transduction Society (STS) has nevertheless in the last decade established within the walls of Weimar an annual interdisciplinary Meeting on "Signal Transduction – Receptors, Mediators and Genes", which is well recognized as a most attractive opportunity to exchange results and ideas in the field.
54.
Posttranslational regulation of Fas ligand function - Voss, Matthias; Lettau, Marcus; Paulsen, Maren; Janssen, Ottmar
The TNF superfamily member Fas ligand acts as a prototypic death factor. Due to its ability to induce apoptosis in Fas (APO-1, CD95) expressing cells, Fas ligand participates in essential effector functions of the immune system. It is involved in natural killer cell- and T cell-mediated cytotoxicity, the establishment of immune privilege, and in termination of immune responses by induction of activation-induced cell death. In addition, Fas ligand-positive tumours may evade immune surveillance by killing Fas-positive tumour-infiltrating cells. Given these strong cytotoxic capabilities of Fas ligand, it is obvious that its function has to be strictly regulated to avoid uncontrolled...
55.
Connexins: a myriad of functions extending beyond assembly of gap junction channels - Dbouk, Hashem A; Mroue, Rana M; El-Sabban, Marwan E; Talhouk, Rabih S
Connexins constitute a large family of trans-membrane proteins that allow intercellular communication and the transfer of ions and small signaling molecules between cells. Recent studies have revealed complex translational and post-translational mechanisms that regulate connexin synthesis, maturation, membrane transport and degradation that in turn modulate gap junction intercellular communication. With the growing myriad of connexin interacting proteins, including cytoskeletal elements, junctional proteins, and enzymes, gap junctions are now perceived, not only as channels between neighboring cells, but as signaling complexes that regulate cell function and transformation. Connexins have also been shown to form functional hemichannels and have roles altogether independent...
56.
Nck adapter proteins: functional versatility in T cells - Lettau, Marcus; Pieper, Jennifer; Janssen, Ottmar
Nck is a ubiquitously expressed adapter protein that is almost exclusively built of one SH2 domain and three SH3 domains. The two isoproteins of Nck are functionally redundant in many aspects and differ in only few amino acids that are mostly located in the linker regions between the interaction modules. Nck proteins connect receptor and non-receptor tyrosine kinases to the machinery of actin reorganisation. Thereby, Nck regulates activation-dependent processes during cell polarisation and migration and plays a crucial role in the signal transduction of a variety of receptors including for instance PDGF-, HGF-, VEGF- and Ephrin receptors. In most cases,...
59.
Regulation of cellular proliferation, differentiation and cell death by activated Raf - Thiel, Gerald; Ekici, Myriam; Rössler, Oliver G
The protein kinases Raf-1, A-Raf and B-Raf connect receptor stimulation with intracellular signaling pathways and function as a central intermediate in many signaling pathways. Gain-of-function experiments shed light on the pleiotropic biological activities of these enzymes. Expression experiments involving constitutively active Raf revealed the essential functions of Raf in controlling proliferation, differentiation and cell death in a cell-type specific manner.
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