Search results for "Skeleton"
showing 10 items of 418 documents
Extremely low frequency electromagnetic fields (ELF-EMFs) induce in vitro angiogenesis process in human endothelial cells.
2008
Effects of extremely low frequency (ELF) electromagnetic fields (EMFs) on activation of angiogenesis were analysed using cultured umbilical human vein endothelial cells (HUVECs). The cultures were exposed to a sinusoidal EMF to intensity of 1 mT, 50 Hz for up to 12 h. EMFs increased the degree of endothelial cell proliferation and tubule formation, coupled by an acceleration in the process of wound healing. Since this process is physiologically accompanied by a large modification in the structural organization of actin and focal adhesions, we analyzed the rearrangement of some cytoskeleton elements demonstrating a major reorganization of the fibres and of the focal adhesion complexes after …
Clustering transmembrane-agrin induces filopodia-like processes on axons and dendrites
2005
The transmembrane form of agrin (TM-agrin) is primarily expressed in the CNS, particularly on neurites. To analyze its function, we clustered TM-agrin on neurons using anti-agrin antibodies. On axons from the chick CNS and PNS as well as on axons and dendrites from mouse hippocampal neurons anti-agrin antibodies induced the dose- and time-dependent formation of numerous filopodia-like processes. The processes appeared within minutes after antibody addition and contained a complex cytoskeleton. Formation of processes required calcium, could be inhibited by cytochalasine D, but was not influenced by staurosporine, heparin or pervanadate. Time-lapse video microscopy revealed that the processes…
Electron microscopy of a double helical tubular filament in keyhole limpet (Megathura crenulata) hemolymph.
1992
A approximately 25 nm hollow double helical filament has been detected ultrastructurally in the cell-free supernatant from hemolymph of the keyhole limpet Megathura crenulata (Gastropoda: Prosobranchia: Fissurellidae). Subsequently, much higher concentrations of this material were found in the cell pellet from hemolymph. Both negative staining and thin sectioning have been performed in an attempt to obtain a preliminary structural characterization of this new filament. It is proposed that the filaments are released or secreted from blood hemocytes in response to bleeding, but it has not been possible to define absolutely an intracellular organelle containing this material. It is shown that …
Cabut, a C2H2 zinc finger transcription factor, is required during Drosophila dorsal closure downstream of JNK signaling.
2005
AbstractDuring dorsal closure, the lateral epithelia on each side of the embryo migrate dorsally over the amnioserosa and fuse at the dorsal midline. Detailed genetic studies have revealed that many molecules are involved in this epithelial sheet movement, either with a signaling function or as structural or motor components of the process. Here, we report the characterization of cabut (cbt), a new Drosophila gene involved in dorsal closure. cbt is expressed in the yolk sac nuclei and in the lateral epidermis. The Cbt protein contains three C2H2-type zinc fingers and a serine-rich domain, suggesting that it functions as a transcription factor. cbt mutants die as embryos with dorsal closure …
Ultrastructure of Joenoides intermedia (Grassé 1952), a symbiotic parabasalid flagellate of Hodotermes mossambicus, and its comparison with other joe…
2003
Light and electron microscopy confirms the validity of the genus Joenoides. The cell is organised like other joeniids with a triangular flagellar area of about two thousand flagella/basal bodies and three privileged basal bodies located apart at the anterior corner of the flagellar area. Characteristically, the two parabasal fibres attached to the basal body #2 are very large and composed of striated subfibres that spread in the cytoplasm, where they sustain Golgi bodies. The flagellar area is surrounded by the axostylar capitulum, which is underlain by a thick layer of preaxostylar fibres, a very strongly amplified component in this species. The axostylar trunk is composed of a bundle of m…
Changes in the density of microtubular networks in mesophyll cells and mesophyll derived protoplasts of Nicotiana and Triticum during leaf development
1993
Changes in the density of microtubular mesh-works were analysed in mesophyll cells and mesophyll derived protoplasts of Nicotiana tabacum L. and Triticum aestivum L. during leaf development. The main purpose of this study was to test whether the low density, if not lack, of microtubular networks recently described in protoplasts that had been isolated from fully differentiated mesophyll cells happened during protoplast isolation or whether the loss of microtubules actually occurred during differentiation of the leaf tissue. Immunofluorescence microscopy showed that the density of the microtubular cytoskeleton in the leaf tissue decreased steadily after cessation of cell growth in both speci…
Spirocurcasone, a diterpenoid with a novel carbon skeleton from Jatropha curcas.
2010
Spirocurcasone (14), a diterpenoid possessing the unprecedented "spirorhamnofolane" skeleton, was isolated from the root barks of Jatropha curcas, a plant extensively cultivated throughout the world, along with 11 known and two other new diterpenoids. The stereostructure of spirocurcasone was established using HRESIMS, NMR, and quantum mechanical calculation of the electronic circular dichroic (ECD) spectrum. Some of the isolated diterpenoids showed a potent activity against L5178Y, a mouse lymphoma cell line.
Artalbic acid, a sesquiterpene with an unusual skeleton from Artemisia alba (Asteraceae) from Sicily
2011
Abstract From the aerial parts of Artemisia alba (Asteraceae) artalbic acid ( 1 ), a sesquiterpene with an unusual skeleton, was isolated. Its structure was elucidated on the basis of extensive proton, 13 C and two-dimensional NMR experiments, as well as by transformation in its methyl ester derivative.
Novel structural insights into F-actin-binding and novel functions of calponin homology domains.
2008
Tandem calponin homology (CH) domains are well-known actin filaments (F-actin) binding motifs. There has been a continuous debate about the details of CH domain-actin interaction, mainly because atomic level structures of F-actin are not available. A recent electron microscopy study has considerably advanced our structural understanding of CH domain:F-actin complex. On the contrary, it has recently also been shown that CH domains can bind other macromolecular systems: two CH domains from separate polypeptides Ncd80, Nuf2 can form a microtubule-binding site, as well as tandem CH domains in the EB1 dimer, while the single C-terminal CH domain of alpha-parvin has been observed to bind to a alp…
0393: Impact of miR-378* and its target desmin intermediate filament on mitochondria distribution in cardiomyocytes
2014
Background MiR-378 and miR-378* microRNAs are derived from an intron of the PGC-1β gene, a regulator of mitochondrial biogenesis. Their expression is either repressed or increased during heart failure depending on the model. Through proteomics approaches, we previously identified new targets of these miRs in H9c2 fetal cardiomyoblasts, among which lactate dehydrogenase for miR-378 and key cytoskeletal proteins for miR-378*. Aims To better assess its role in energy metabolism and differentiation; we overexpressed miR-378 and miR-378* in primary neonate rat cardiomyocytes (NRC) that are more differentiated and less proliferative than H9c2 cardiomyoblasts. Results We identified desmin as a new…