The use of fluorescent probes to detect structural changes in membranes of the endoplasmic reticulum of the liver in rats kept on an atherogenic diet

1980 ◽  
Vol 90 (2) ◽  
pp. 1070-1072
Author(s):  
G. E. Dobretsov ◽  
V. Z. Lankin ◽  
T. A. Borshchevskaya ◽  
V. A. Petrov ◽  
V. N. Ivanov ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Fluorescent Probes ◽  
Structural Changes ◽  
Atherogenic Diet ◽  
Structural Changes In Membranes

scholarly journals Zika virus replication in glioblastoma cells: electron microscopic tomography shows 3D arrangement of endoplasmic reticulum, replication organelles, and viral ribonucleoproteins

2021 ◽  
Author(s):  
Johannes Wieland ◽  
Stefan Frey ◽  
Ulrich Rupp ◽  
Sandra Essbauer ◽  
Rüdiger Groß ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Line ◽  
Zika Virus ◽  
Structural Changes ◽  
Electron Tomography ◽  
Glioblastoma Cells ◽  
Electron Microscopic ◽  
N Protein ◽  
Ribonucleoprotein Complexes ◽  
Infected Cells

AbstractStructural changes of two patient-derived glioblastoma cell lines after Zika virus infection were investigated using scanning transmission electron tomography on high-pressure-frozen, freeze-substituted samples. In Zika-virus-infected cells, Golgi structures were barely visible under an electron microscope, and viral factories appeared. The cytosol outside of the viral factories resembled the cytosol of uninfected cells. The viral factories contained largely deranged endoplasmic reticulum (ER), filled with many so-called replication organelles consisting of a luminal vesicle surrounded by the ER membrane. Viral capsids were observed in the vicinity of the replication organelles (cell line #12537 GB) or in ER cisternae at large distance from the replication organelles (cell line #15747 GB). Near the replication organelles, we observed many about 100-nm-long filaments that may represent viral ribonucleoprotein complexes (RNPs), which consist of the RNA genome and N protein oligomers. In addition, we compared Zika-virus-infected cells with cells infected with a phlebovirus (sandfly fever Turkey virus). Zika virions are formed in the ER, whereas phlebovirus virions are assembled in the Golgi apparatus. Our findings will help to understand the replication cycle in the virus factories and the building of the replication organelles in glioblastoma cells.

scholarly journals Synthesis and Pharmacological Characterization of 2-Aminoethyl Diphenylborinate (2-APB) Derivatives for Inhibition of Store-Operated Calcium Entry (SOCE) in MDA-MB-231 Breast Cancer Cells

2020 ◽  
Vol 21 (16) ◽  
pp. 5604 ◽  
Author(s):  
Achille Schild ◽  
Rajesh Bhardwaj ◽  
Nicolas Wenger ◽  
Dominic Tscherrig ◽  
Palanivel Kandasamy ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Endoplasmic Reticulum ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Structural Changes ◽  
Calcium Entry ◽  
Imaging Plate ◽  
Ip3 Receptors ◽  
Pharmacological Characterization ◽  
Store Operated Calcium Entry

Calcium ions regulate a wide array of physiological functions including cell differentiation, proliferation, muscle contraction, neurotransmission, and fertilization. The endoplasmic reticulum (ER) is the major intracellular Ca2+ store and cellular events that induce ER store depletion (e.g., activation of inositol 1,4,5-triphosphate (IP3) receptors) trigger a refilling process known as store-operated calcium entry (SOCE). It requires the intricate interaction between the Ca2+ sensing stromal interaction molecules (STIM) located in the ER membrane and the channel forming Orai proteins in the plasma membrane (PM). The resulting active STIM/Orai complexes form highly selective Ca2+ channels that facilitate a measurable Ca2+ influx into the cytosol followed by successive refilling of the ER by the sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA). STIM and Orai have attracted significant therapeutic interest, as enhanced SOCE has been associated with several cancers, and mutations in STIM and Orai have been linked to immunodeficiency, autoimmune, and muscular diseases. 2-Aminoethyl diphenylborinate (2-APB) is a known modulator and depending on its concentration can inhibit or enhance SOCE. We have synthesized several novel derivatives of 2-APB, introducing halogen and other small substituents systematically on each position of one of the phenyl rings. Using a fluorometric imaging plate reader (FLIPR) Tetra-based calcium imaging assay we have studied how these structural changes of 2-APB affect the SOCE modulation activity at different compound concentrations in MDA-MB-231 breast cancer cells. We have discovered 2-APB derivatives that block SOCE at low concentrations, at which 2-APB usually enhances SOCE.

Why fluorescent probes for endoplasmic reticulum are selective: an experimental and QSAR-modelling study

2003 ◽  
Vol 78 (6) ◽  
pp. 323-332 ◽  
Author(s):  
J Colston ◽  
Rw Horobin ◽  
F Rashid-Doubell ◽  
J Pediani ◽  
Kk Johal
Keyword(s):  
Endoplasmic Reticulum ◽  
Fluorescent Probes ◽  
Qsar Modelling ◽  
Modelling Study

scholarly journals Endoplasmic reticulum targeting fluorescent probes to image mobile Zn2+

2019 ◽  
Vol 10 (47) ◽  
pp. 10881-10887 ◽  
Author(s):  
Le Fang ◽  
Giuseppe Trigiante ◽  
Rachel Crespo-Otero ◽  
Chris S. Hawes ◽  
Michael P. Philpott ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Fluorescent Probes ◽  
Biological Processes ◽  
Er Targeting ◽  
Endoplasmic Reticulum Targeting

Two endoplasmic reticulum (ER) targeting probes were developed to image mobile Zn2+ to help understand Zn2+ related biological processes in the ER.

scholarly journals Agonist-evoked inositol trisphosphate receptor (IP3R) clustering is not dependent on changes in the structure of the endoplasmic reticulum

2006 ◽  
Vol 394 (1) ◽  
pp. 57-66 ◽  
Author(s):  
Mark Chalmers ◽  
Michael J. Schell ◽  
Peter Thorn
Keyword(s):  
Endoplasmic Reticulum ◽  
Protein Interactions ◽  
Cell Activation ◽  
Structural Changes ◽  
Fluorescent Protein ◽  
Cluster Formation ◽  
Yellow Fluorescent Protein ◽  
Resting Cells ◽  
Trisphosphate Receptor ◽  
Er Membrane

The size and number of IP3R (inositol 1,4,5-trisphosphate receptor) clusters located on the surface of the ER (endoplasmic reticulum) is hypothesized to regulate the propagation of Ca2+ waves in cells, but the mechanisms by which the receptors cluster are not understood. Using immunocytochemistry, live-cell imaging and heterologous expression of ER membrane proteins we have investigated IP3R clustering in the basophilic cell line RBL-2H3 following the activation of native cell-surface antigen receptors. IP3R clusters are present in resting cells, and upon receptor stimulation, form larger aggregates. Cluster formation and maintenance required the presence of extracellular Ca2+ in both resting and stimulated cells. Using transfection with a marker of the ER, we found that the ER itself also showed structural changes, leading to an increased number of ‘hotspots’, following antigen stimulation. Surprisingly, however, when we compared the ER hotspots and IP3R clusters, we found them to be distinct. Imaging of YFP (yellow fluorescent protein)–IP3R transfected in to living cells confirmed that IP3R clustering increased upon stimulation. Photobleaching experiments showed that the IP3R occupied a single contiguous ER compartment both before and after stimulation, suggesting a dynamic exchange of IP3R molecules between the clusters and the surrounding ER membrane. It also showed a decrease in the mobile fraction after cell activation, consistent with receptor anchoring within clusters. We conclude that IP3R clustering in RBL-2H3 cells is not simply a reflection of bulk-changes in ER structure, but rather is due to the receptor undergoing homotypic or heterotypic protein–protein interactions in response to agonist stimulation.

Interrelations between the Parasitophorous Vacuole ofToxoplasma gondiiand Host Cell Organelles

2005 ◽  
Vol 11 (2) ◽  
pp. 166-174 ◽  
Author(s):  
Rodrigo Cardoso Magno ◽  
Lorian Cobra Straker ◽  
Wanderley de Souza ◽  
Marcia Attias
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Host Cell ◽  
Fluorescent Probes ◽  
Parasitophorous Vacuole ◽  
Laser Scanning Microscopy ◽  
Cell Organelles ◽  
Apical Side ◽  
Transmission Electron

Toxoplasma gondii, the causative agent of toxoplasmosis, is capable of actively penetrating and multiplying in any nucleated cell of warm-blooded animals. Its survival strategies include escape from fusion of the parasitophorous vacuole with host cell lysosomes and rearrangement of host cell organelles in relation to the parasitophorous vacuole. In this article we report the rearrangement of host cell organelles and elements of the cytoskeleton of LLCMK2 cells, a lineage derived from green monkey kidney epithelial cells, in response to infection byT. gondiitachyzoites. Transmission electron microscopy made on flat embedded monolayers cut horizontally to the apical side of the cells or field emission scanning electron microscopy of monolayers scraped with scotch tape before sputtering showed that association of mitochondria to the vacuole is much less frequent than previously described. On the other hand, all parasitophorous vacuoles were surrounded by elements of the endoplasmic reticulum. These data were complemented by observations by laser scanning microscopy using fluorescent probes from mitochondria and endoplasmic reticulum and reinforced by three-dimensional reconstruction from serial sections observed by transmission electron microscopy and labeling of mitochondria and endoplasmic reticulum by fluorescent probes.

Immunologically Induced Changes in the Tonsillar Crypt Epithelium

1979 ◽  
Vol 88 (3) ◽  
pp. 397-406 ◽  
Author(s):  
John F. Schmedtje ◽  
Jose J. Chinea ◽  
Daniel W. Kletzing
Keyword(s):  
Endoplasmic Reticulum ◽  
Epithelial Cells ◽  
Plasma Membranes ◽  
Structural Changes ◽  
Direct Injection ◽  
Lymphatic Tissue ◽  
Microscopic Anatomy ◽  
Crypt Epithelium ◽  
Fine Structures ◽  
Induced Changes

The normal gross and microscopic anatomy of the palatine tonsil of the rabbit was observed, and following the direct injection of antigenic substance, structural changes were noted in the crypt epithelium. A cold light laryngoscope tube was used to inject ovalbumin or bovine serum albumin, plus Freund's complete adjuvant, into the subepithelial lymphatic tissue. Five weeks later subcutaneous challenge injections of the same protein produced increased numbers and proportions of infiltrated small lymphocytes and medium-sized lymphocytes containing a highly organized granular endoplasmic reticulum. These cells occupied wide intercellular passageways. Epithelial plasma membranes that faced these passageways remained smooth, but other surfaces of the same epithelial cells acquired vastly increased numbers of microvilli. The surfaces of other epithelial cells that faced each other also showed microvilli. These microvilli faced expanded interfacial canals. Increased numbers of small lymphocytes were observed emigrating through postcapillary venules immediately beneath the epithelium. The microvilli and other fine structures of tonsillar crypt epithelial cells are compared with similar structures of epithelial cells of the thymus. The experimentally induced increase in microvilli suggests the possibility that tonsillar crypt epithelial cells make a secretory contribution to local immune reactions.

Sign in / Sign up

Export Citation Format

Share Document