Search results for "ENDOCYTOSIS"
showing 10 items of 185 documents
Endocytosis in cultured neurons is altered by chronic alcohol exposure.
2010
Endocytosis is required for many cellular pivotal processes, including membrane recycling, nutrient uptake, and signal transduction. This complex process is particularly relevant in polarized cells, such as neurons. Previous studies have demonstrated that alcohol alters intracellular traffic, including endocytosis, in several cell types. However, information on the effect of chronic alcohol exposure on this process in neurons is scarce. As an approach, we investigated the effect of alcohol exposure on the internalization of two widely used endocytic markers, albumin and transferrin, in developing hippocampal neurons in primary culture. The effect of this treatment on the levels of several r…
Chapter 7 Cell Protective Functions of Secretory Clusterin (sCLU)
2009
Secretory clusterin (sCLU) is found as an 80-kDa glycoprotein in virtually all body fluids, in serum it is associated with high-density lipoprotein (HDL). Here, we discuss demonstrated and proposed mechanisms of the cytoprotective functions of sCLU in instances of apoptosis, necrosis, and disease. These include prevention from cell damage by lipid oxidation in blood vessels, removal of dead cell remnants in tissues undergoing various forms of cell death, and clearance of harmful extracellular molecules such as amyloid beta (Aβ) by endocytosis or transcytosis. All these functions may reflect the propensity of sCLU to bind to a wide spectrum of hydrophobic molecules on one hand and to specifi…
In vitro fusion of phagosomes with different endocytic organelles from J774 macrophages.
1998
We describe novel biochemical and electron microscopy assays to investigate in vitro fusion of latex bead phagosomes with three different endocytic organelle fractions from J774 macrophages. After formation, early phagosomes fuse avidly with early and late endosomes and for a longer period of time with lysosomes, but they subsequently become fusion-incompetent. The fusion of early, but not late, phagosomes with all three endocytic fractions could be significantly stimulated by Rab5. In contrast to other cell types investigated, this Rab is uniquely enriched on both early and late endosomes in J774 macrophages. Moreover, exogenous Rab5 stimulates homotypic fusion between both sets of organel…
Characterization of Endocytic Components of Liver Nonparenchymal Cells
1993
Liver is made up of at least five important cell types: hepatocytes, endothelial cells, Kupffer cells, pit cells, and fat-storing cells. These cells have been broadly classified into two groups: parenchymal cells, or the hepatocytes which comprise almost 65% of the liver cells (Miyai, 1979), and nonparenchymal cells, to which all the other cell types belong.
Morphology of follicle cells of Libellulidae (Odonata)
2011
In libellulids, mature oocyte size varies within and between individual ovaries. The regulating mechanism is not yet understood. Variations in the contents of the follicle cells, and thereby their ability to secrete material into the oocyte, might explain some of the observed differences in oocyte size. We therefore investigated the follicle cell surface, the interstitial space width between follicle cells and between follicle cells and oocytes, the number of nuclei, and the cell compartment proportions using scanning and transmission electron microscopy. In all investigated species, the follicle cells were covered by a basal lamina. We found cytoplasmic microvilli and septate junctions. As…
Cellular interactions ofCandida albicanswith human oral epithelial cells and enterocytes
2010
The human pathogenic fungus Candida albicans can cause systemic infections by invading epithelial barriers to gain access to the bloodstream. One of the main reservoirs of C. albicans is the gastrointestinal tract and systemic infections predominantly originate from this niche. In this study, we used scanning electron and fluorescence microscopy, adhesion, invasion and damage assays, fungal mutants and a set of fungal and host cell inhibitors to investigate the interactions of C. albicans with oral epithelial cells and enterocytes. Our data demonstrate that adhesion, invasion and damage by C. albicans depend not only on fungal morphology and activity, but also on the epithelial cell type an…
Hunting for the high-affinity state of G-protein-coupled receptors with agonist tracers: Theoretical and practical considerations for positron emissi…
2019
Abstract The concept of the high‐affinity state postulates that a certain subset of G‐protein‐coupled receptors is primarily responsible for receptor signaling in the living brain. Assessing the abundance of this subset is thus potentially highly relevant for studies concerning the responses of neurotransmission to pharmacological or physiological stimuli and the dysregulation of neurotransmission in neurological or psychiatric disorders. The high‐affinity state is preferentially recognized by agonists in vitro. For this reason, agonist tracers have been developed as tools for the noninvasive imaging of the high‐affinity state with positron emission tomography (PET). This review provides an…
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…
Retinol encapsulated into amorphous Ca2+ polyphosphate nanospheres acts synergistically in MC3T3-E1 cells
2015
Both the quality and quantity of collagen, the major structural component of the skin, decrease in aging skin. We succeeded to encapsulate retinol into amorphous inorganic polyphosphate (polyP) nanoparticles together with calcium ions ("aCa-polyP-NP"), under formation of amorphous Ca-polyP/retinol nanospheres ("retinol/aCa-polyP-NS"). The globular nanospheres are not cytotoxic, show an almost uniform size of ≈ 45 nm and have a retinol content of around 25%. Both components of those nanospheres, retinol and the aCa-polyP-NP, if administered together, caused a strong increase in proliferation of mouse calvaria MC3T3 cells. The expressions of collagen types I, II and III genes, but not the exp…
Polyaminoacid–doxorubicin prodrug micelles as highly selective therapeutics for targeted cancer therapy
2016
An amphiphilic copolymer carrying high-dose doxorubicin (21% on a weight basis), PHEA–EDA–P,C–Doxo, was prepared by coupling doxorubicin with a biocompatible polyaminoacid through a pH-sensitive spacer. Additional derivatization with 4-pentynoic acid endows it with self-assembling properties by means of π–π stacking. These micelles can be triggered to promptly release drug in lysosomes (∼40% in 12 h) through pH-dependent micelle hydrolysis after uptake. In vitro tests on co-cultures of cancer (MDA-MB 231) and normal (HB-2) breast cells proved that the conjugate was selectively internalized into the former rather than normal cells, exploiting the caveolae-dependent endocytosis pathway, expla…