Search results for "cytoskeleton"
showing 10 items of 272 documents
Human neuroblastoma SH-SY5Y cell line: neurosteroid-producing cell line relying on cytoskeletal organization.
2000
Pregnenolone, the precursor of all steroids, is synthesized by CNS structures. The synthesis requires an obligatory step involving cholesterol transport to mitochondrial cytochrome P450-cholesterol side chain cleavage (cytP450scc), although the underlying mechanism(s) are still mostly unknown. We used the human neuroblastoma SH-SY5Y cell line to investigate cytP450scc expression and activity and to establish a role of cytoskeleton in pregnenolone synthesis. Immunocytochemical and biochemical approaches revealed that undifferentiated as well as differentiated cells either by retinoic acid (RA) or phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA), possess cytP450scc and rapidly synthes…
Efectos de la exposición crónica al etanol sobre el tráfico intracelular y citoesqueleto como factores implicados en la migración neuronal
2013
El consumo de etanol durante la gestación puede inducir una serie de alteraciones graves en el desarrollo del feto, la manifestación más extrema da lugar al Síndrome Alcohólico Fetal (SAF). La exposición prenatal al alcohol es la causa conocida y, además evitable, más importante de retraso mental en el mundo occidental. Además de déficits cognitivos, los niños con SAF presentan múltiples anomalías estructurales en el sistema nervioso central, como reducción de la masa cerebral, y a nivel celular, daños en la migración neuronal, en el proceso de formación de espinas dendríticas y establecimiento de sinapsis. En la actualidad, los mecanismos moleculares implicados en la teratogénesis inducida…
The angiopoietin-Tie2 pathway regulates Purkinje cell dendritic morphogenesis in a cell-autonomous manner.
2021
Neuro-vascular communication is essential to synchronize central nervous system development. Here, we identify angiopoietin/Tie2 as a neuro-vascular signaling axis involved in regulating dendritic morphogenesis of Purkinje cells (PCs). We show that in the developing cerebellum Tie2 expression is not restricted to blood vessels, but it is also present in PCs. Its ligands angiopoietin-1 (Ang1) and angiopoietin-2 (Ang2) are expressed in neural cells and endothelial cells (ECs), respectively. PC-specific deletion of Tie2 results in reduced dendritic arborization, which is recapitulated in neural-specific Ang1-knockout and Ang2 full-knockout mice. Mechanistically, RNA sequencing reveals that Tie…
Myelin Proteome Analysis: Methods and Implications for the Myelin Cytoskeleton
2012
Myelin, the multilayered membrane that enwraps and insulates neuronal axons for fast signal propagation, is a plasma membrane specialization of oligodendrocytes and Schwann cells in the central and peripheral nervous system, respectively. Here we provide our lab protocols for the puri fi cation of myelin from mouse brains and for gel-based and gel-free proteomic applications, as well as a brief discussion with respect to our current knowledge of the myelin cytoskeleton.
Aggregation versus Biological Activity in Gold(I) Complexes. An Unexplored Concept
2021
The aggregation process of a series of mono- and dinuclear gold(I) complexes containing a 4-ethynylaniline ligand and a phosphane at the second coordination position (PR3-Au-C≡CC6H4-NH2, complexes 1-5, and (diphos)(Au-C≡CC6H4-NH2)2, complexes 6-8), whose biological activity was previously studied by us, has been carefully analyzed through absorption, emission, and NMR spectroscopy, together with dynamic light scattering and small-angle X-ray scattering. These experiments allow us to retrieve information about how the compounds enter the cells. It was observed that all compounds present aggregation in fresh solutions, before biological treatment, and thus they must be entering the cells as a…
Proteins of Muscle and the Cytoskeleton
1994
The contractile elements of striated vertebrate skeletal muscle, the myofibrils, contain thin filaments, which are 6 nm in diameter and consist mainly of actin, and thicker myosin filaments with a diameter of 16 nm (Fig. 10.1). During muscle contraction, the filaments undergo a sliding movement relative to each other (sliding filament mechanism). This is brought about by the reversible formation of bridges between the myosin molecules and the actin filaments, which bind, change their conformation and then dissociate (bridge cycle). The required energy is supplied by the hydrolysis of ATP. The sliding distance (step size) per molecule of ATP hydrolysed is controversial; the most recent measu…
Vitrification of Immature Porcine Oocytes: Effects of Lipid Droplets, Temperature, Cytoskeleton, and Addition and Removal of Cryoprotectant
1998
Three experiments were conducted to investigate the effects of single-step and stepwise exposure to and removal of cryoprotectant, of temperature, and of a cytoskeletal relaxant on the development of germinal vesicle porcine oocytes to the M-II stage. In experiment I, noncooled cumulus-oocyte complexes (COCs) were treated using single-step/stepwise exposure to ethylene glycol (EG) and removal at 23 or 42 degrees C. Stepwise exposure to EG and dilution at 42 degrees C were found to have a positive effect on the COC developmental rate. In experiment II, also without cooling, COCs were treated with Cytochalasin B at 42 degrees C using single-step and stepwise protocols of exposure to and remov…
Loss of surface fibronectin after infection of cultured cells by HSV-1 and 2
1985
Fibronectin is lost from the surface of HSV infected cells during cell rounding. In order to investigate also the fate of fibronectin during the process of HSV-induced cell-fusion, BHK, Vero as well as primary or secondary rabbit kidney cells were infected with HSV-1 strains producing cell-fusion. By immunofluorescence and immunoelectron microscopy a considerable loss of fibronectin after HSV infection could be demonstrated leaving only irregular clumps of fibronectin containing virus particles on the cell surface. Decrease and disarrangement of fibronectin was similar during cell rounding and cell fusion. Loss of Fibronectin was closely connected with the two types of the cytopathic effect…
Polyphosphoinositide Metabolism and Golgi Complex Morphology in Hippocampal Neurons in Primary Culture is Altered by Chronic Ethanol Exposure
2012
Aims : Ethanol affects not only the cytoskeletal organization and activity, but also intracellular trafficking in neurons in the primary culture. Polyphosphoinositide (PPIn) are essential regulators of many important cell functions, including those mentioned, cytoskeleton integrity and intracellular vesicle trafficking. Since information about the effect of chronic ethanol exposure on PPIn metabolism in neurons is scarce, this study analysed the effect of this treatment on three of these phospholipids. Methods : Phosphatidylinositol (PtdIns) levels as well as the activity and/or levels of enzymes involved in their metabolism were analysed in neurons chronically exposed to ethanol. The level…
Heterochromatin Networks: Topology, Dynamics, and Function (a Working Hypothesis)
2021
Open systems can only exist by self-organization as pulsing structures exchanging matter and energy with the outer world. This review is an attempt to reveal the organizational principles of the heterochromatin supra-intra-chromosomal network in terms of nonlinear thermodynamics. The accessibility of the linear information of the genetic code is regulated by constitutive heterochromatin (CHR) creating the positional information in a system of coordinates. These features include scale-free splitting-fusing of CHR with the boundary constraints of the nucleolus and nuclear envelope. The analysis of both the literature and our own data suggests a radial-concentric network as the main structural…