Dispersal of Golgi apparatus in nocodazole-treated fibroblasts is a kinesin-driven process

1997 ◽  
Vol 110 (19) ◽  
pp. 2495-2505 ◽  
Author(s):  
A.A. Minin
Keyword(s):  
Golgi Apparatus ◽  
Human Skin ◽  
Cell Types ◽  
Human Skin Fibroblasts ◽  
Low Concentrations ◽  
Complete Disruption ◽  
Rat Fibroblasts ◽  
Different Cell Types ◽  
Blocking Analysis ◽  
Perinuclear Area

The morphology and location of the Golgi apparatus (GA) has been shown to change upon microtubule (Mt) depolymerization. The GA in different cell types undergoes fragmentation and dispersal throughout the cytoplasm upon treatment with nocodazole. In this study experiments were performed on human skin fibroblasts (HSFs) and rat fibroblasts (REF 52) to determine whether the dispersal of GA in HSFs treated with nocodazole is dependent on Mts that show the higher resistance to this Mt-depolymerizing drug. It is shown here that nocodazole at concentrations as low as 100 nM caused the GA to disperse in treated fibro-blasts that still contained a fairly high amount of Mts. Antibody-blocking analysis of Mts after injection of biotin-tubulin into the HSFs was used to show that nocodazole at low concentrations induced the stabilization of the remaining Mts. The complete disruption of Mts by the incubation of HSFs at 0 degrees C prevented the dispersal of GA from the perinuclear area when the cells were subsequently warmed to 37 degrees C in the presence of nocodazole. Micro-injection of the well-characterized HD antibody against kinesin but not the preimmune IgG caused inhibition of GA dispersal in HSFs by nocodazole. These data demonstrate that the dispersal of GA in the cytoplasm of nocodazole-treated HSFs is a kinesin-driven process with stable Mts serving as tracks.

Maitotoxin activates a nonselective cation channel and a P2Z/P2X7-like cytolytic pore in human skin fibroblasts

1999 ◽  
Vol 277 (4) ◽  
pp. C755-C765 ◽  
Author(s):  
William P. Schilling ◽  
William G. Sinkins ◽  
Mark Estacion
Keyword(s):  
Human Skin ◽  
Organic Cation ◽  
Cell Types ◽  
Skin Fibroblasts ◽  
Cation Channels ◽  
Human Skin Fibroblasts ◽  
Cell Level ◽  
Receptor Stimulation ◽  
Nonselective Cation Channels ◽  
Relative Molecular Weight

Maitotoxin (MTX), a potent cytolytic agent, activates Ca2+ entry via nonselective cation channels in virtually all types of cells. The identity of the channels involved and the biochemical events leading to cell lysis remain unknown. In the present study, the effect of MTX on plasmalemmal permeability of human skin fibroblasts was examined. MTX produced a time- and concentration-dependent increase in cytosolic free Ca2+ concentration that depended on extracellular Ca2+ and was relatively insensitive to blockade by extracellular lanthanides. MTX also produced a time- and concentration-dependent increase in plasmalemma permeability to larger molecules as indicated by 1) uptake of ethidium (314 Da), 2) uptake of YO-PRO-1 (375 Da), 3) release of intracellular fura 2 (636 Da), 4) uptake of POPO-3 (715 Da), and, ultimately, 5) release of lactate dehydrogenase (relative molecular weight of 140,000). At the single cell level, uptake of YO-PRO-1 correlated in time with the appearance of large MTX-induced membrane currents carried by the organic cation, N-methyl-d-glucamine (167 Da). Thus MTX initially activates Ca2+-permeable cation channels and later induces the formation of large pores. These effects of MTX on plasmalemmal permeability are similar to those seen on activation of P2Z/P2X7 receptors in a variety of cell types, raising the intriguing possibility that MTX and P2Z/P2X7 receptor stimulation activate a common cytolytic pore.

Selective enrichment and biochemical characterization of seven human skin fibroblasts cell types in vitro

1989 ◽  
Vol 180 (1) ◽  
pp. 84-93 ◽  
Author(s):  
H.Peter Rodemann ◽  
Klaus Bayreuther ◽  
Pal I. Francz ◽  
Klaus Dittmann ◽  
Mario Albiez
Keyword(s):  
Human Skin ◽  
Biochemical Characterization ◽  
Cell Types ◽  
Skin Fibroblasts ◽  
Human Skin Fibroblasts ◽  
Selective Enrichment

scholarly journals The influence of LTS-4, a saponoside from Lysimachia thyrsiflora L., on human skin fibroblasts and human melanoma cells

2008 ◽  
Vol 13 (4) ◽  
Author(s):  
Agnieszka Galanty ◽  
Marta Michalik ◽  
Łukasz Sędek ◽  
Irma Podolak
Keyword(s):  
Cell Growth ◽  
Cell Motility ◽  
Human Skin ◽  
Cell Types ◽  
Inhibitory Effect ◽  
Human Melanoma ◽  
Skin Fibroblasts ◽  
Dependent Manner ◽  
Human Skin Fibroblasts ◽  
Dose Dependent

AbstractWe investigated the effect of a triterpene saponoside from Lysimachia thyrsiflora L. upon the viability, proliferation, morphology and cell motility of human melanoma HTB-140 cells and human skin fibroblasts (HSFs). The compound, denoted LTS-4, decreased the viability and rate of cell growth of both cell types in a time-and dose-dependent manner, and proved cytotoxic against cancer cells at significantly lower concentrations than for fibroblasts. LTS-4 also affected the morphology of the examined cells, causing vacuolisation and actin cytoskeleton disintegration, and had an inhibitory effect on the tumour cell motility.

scholarly journals Internalization and sorting of a fluorescent analogue of glucosylceramide to the Golgi apparatus of human skin fibroblasts: utilization of endocytic and nonendocytic transport mechanisms.

1994 ◽  
Vol 125 (4) ◽  
pp. 769-781 ◽  
Author(s):  
O C Martin ◽  
R E Pagano
Keyword(s):  
Plasma Membrane ◽  
Golgi Apparatus ◽  
Nuclear Envelope ◽  
Human Skin ◽  
Skin Fibroblasts ◽  
Atp Depletion ◽  
Human Skin Fibroblasts ◽  
Intracellular Membranes ◽  
Fluorescent Analogues ◽  
Fluorescent Lipid

We examined the uptake and intracellular transport of the fluorescent glucosylceramide analogue N-[5-(5,7-dimethyl BODIPYTM)-1-pentanoyl]-glucosyl sphingosine (C5-DMB-GlcCer) in human skin fibroblasts, and we compared its behavior to that of the corresponding fluorescent analogues of sphingomyelin, galactosylceramide, and lactosylceramide. All four fluorescent analogues were readily transferred from defatted BSA to the plasma membrane during incubation at 4 degrees C. When cells treated with C5-DMB-GlcCer were washed, warmed to 37 degrees C, and subsequently incubated with defatted BSA to remove fluorescent lipid at the cell surface, strong fluorescence was observed at the Golgi apparatus, as well as weaker labeling at the nuclear envelope and other intracellular membranes. Similar results were obtained with C5-DMB-galactosylceramide, except that labeling of the Golgi apparatus was weaker than with C5-DMB-GlcCer. Internalization of C5-DMB-GlcCer was not inhibited by various treatments, including ATP depletion or warming to 19 degrees C, and biochemical analysis demonstrated that the lipid was not metabolized during its internalization. However, accumulation of C5-DMB-GlcCer at the Golgi apparatus was reduced when cells were treated with a nonfluorescent analogue of glucosylceramide, suggesting that accumulation of C5-DMB-GlcCer at the Golgi apparatus was a saturable process. In contrast, cells treated with C5-DMB-analogues of sphingomyelin or lactosylceramide internalized the fluorescent lipid into a punctate pattern of fluorescence during warming at 37 degrees C, and this process was temperature and energy dependent. These results with C5-DMB-sphingomyelin and C5-DMB-lactosylceramide were analogous to those obtained with another fluorescent analogue of sphingomyelin in which labeling of endocytic vesicles and plasma membrane lipid recycling were documented (Koval, M., and R. E. Pagano. 1990. J. Cell Biol. 111:429-442). Incubation of perforated cells with C5-DMB-sphingomyelin resulted in prominent labeling of the nuclear envelope and other intracellular membranes, similar to the pattern observed with C5-DMB-GlcCer in intact cells. These observations are consistent with the transbilayer movement of fluorescent analogues of glucosylceramide and galactosylceramide at the plasma membrane and early endosomes of human skin fibroblasts, and suggest that both endocytic and nonendocytic pathways are used in the internalization of these lipids from the plasma membrane.

Models for positional signalling with application to the dorsoventral patterning of insects and segregation into different cell types

Development ◽  
1989 ◽  
Vol 107 (Supplement) ◽  
pp. 169-180 ◽  
Author(s):  
Hans Meinhardt
Keyword(s):  
Positional Information ◽  
Cell Types ◽  
Ventral Side ◽  
Homogeneous Distribution ◽  
Dorsoventral Patterning ◽  
High Concentration ◽  
Low Concentrations ◽  
Homogeneous Cell ◽  
Pattern Forming ◽  
Different Cell Types

Models of pattern formation and possible molecular realizations are discussed and compared with recent experimental observations. In application to the dorsoventral patterning of insects, it is shown that a superposition of two pattern-forming reactions is required. The first system generates the overall dorsoventral polarity of the oocyte, the second generates the positional information proper with a stripe-like region of high concentration along the ventral side of the embryo. A single reaction would be insufficient since the two reactions require different parameters. The model accounts for the orientation of the DV axes of the oocytes in the ovary of Musca domestica and Sarcophaga, independent of the DV axis of the mother, for the formation of several ventral furrows in the absence of the primary gurken/torpedo system in Drosophila, as well as for the good size regulation of the dorsoventral axis as observed in some insect species. Segregation of a homogeneous cell population into different cell types requires autocatalytic processes that saturate at relatively low concentrations and nondiffusible substances responsible for the autocatalytic feedback loops. Thus, these loops can be realized directly on the gene level via their gene products, for instance, by the mutual repression of two genes. A balance of the two cell types is achieved by a long-ranging substance interfering with the self-enhancing process. This substance is expected to have a more or less homogeneous distribution. This model accounts for the reestablishment of the correct proportion after an experimental interference and the change of determination after transplantation. Applications to the segregation of prestalk and prespore cells in Dictyostelium and of neuroblast cells from the ventral ectoderm in Drosophila are provided.

Study of the Molecular Architecture of Keratin Filaments by Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 118-119
Author(s):  
U. Aebi ◽  
P. Rew ◽  
T.-T. Sun
Keyword(s):  
Electron Microscopy ◽  
Structural Organization ◽  
Cell Types ◽  
Structural Features ◽  
Molecular Architecture ◽  
The Past ◽  
Keratin Filaments ◽  
Different Types ◽  
10 Nm Filaments ◽  
Different Cell Types

Various types of intermediate-sized (10-nm) filaments have been found and described in many different cell types during the past few years. Despite the differences in the chemical composition among the different types of filaments, they all yield common structural features: they are usually up to several microns long and have a diameter of 7 to 10 nm; there is evidence that they are made of several 2 to 3.5 nm wide protofilaments which are helically wound around each other; the secondary structure of the polypeptides constituting the filaments is rich in ∞-helix. However a detailed description of their structural organization is lacking to date.

Processing and Characterization of Recombinant von Willebrand Factor Expressed in Different Cell Types Using a Vaccinia Virus Vector

1992 ◽  
Vol 67 (01) ◽  
pp. 154-160 ◽  
Author(s):  
P Meulien ◽  
M Nishino ◽  
C Mazurier ◽  
K Dott ◽  
G Piétu ◽  
...  
Keyword(s):  
Vaccinia Virus ◽  
Von Willebrand Factor ◽  
Human Fibroblasts ◽  
Active Form ◽  
Cell Types ◽  
Biologically Active ◽  
L Cells ◽  
Von Willebrand ◽  
Different Cell Types ◽  
Willebrand Factor

SummaryThe cloning of the cDNA encoding von Willebrand factor (vWF) has revealed that it is synthesized as a large precursor (pre-pro-vWF) molecule and it is now clear that the prosequence or vWAgll is responsible for the intracellular multimerization of vWF. We have cloned the complete vWF cDNA and expressed it using a recombinant vaccinia virus as vector. We have characterized the structure and function of the recombinant vWF (rvWF) secreted from five different cell types: baby hamster kidney (BHK), Chinese hamster ovary (CHO), human fibroblasts (143B), mouse fibroblasts (L) and primary embryonic chicken cells. Forty-eight hours after infection, the quantity of vWF antigen found in the cell supernatant varied from 3 to 12 U/dl depending on the cell type. By SDS-agarose gel electrophoresis, the percentage of high molecular weight forms of vWF varied from 39 to 49% relative to normal plasma for BHK, CHO, 143B and chicken cells but was less than 10% for L cells. In all cell types, the two anodic subbands of each multimer were missing. The two cathodic subbands were easily detected only in BHK and L cells. By SDS-PAGE of reduced samples, pro-vWF was present in similar quantity to the fully processed vWF subunit in L cells, present in moderate amounts in BHK and CHO and in very low amounts in 143B and chicken cells. rvWF from all cells bound to collagen and to platelets in the presence of ristocetin, the latter showing a high correlation between binding efficiency and degree of multimerization. rvWF from all cells was also shown to bind to purified FVIII and in this case binding appeared to be independent of the degree of multimerization. We conclude that whereas vWF is naturally synthesized only by endothelial cells and megakaryocytes, it can be expressed in a biologically active form from various other cell types.

Role of Transcriptional Read-Through in PRE Activity in Drosophila melanogaster

Acta Naturae ◽  
2016 ◽  
Vol 8 (2) ◽  
pp. 79-86 ◽  
Author(s):  
P. V. Elizar’ev ◽  
D. V. Lomaev ◽  
D. A. Chetverina ◽  
P. G. Georgiev ◽  
M. M. Erokhin
Keyword(s):  
Dna Sequences ◽  
Cell Types ◽  
Transcription Terminator ◽  
Response Elements ◽  
Polycomb Response Elements ◽  
The Individual ◽  
Multicellular Organisms ◽  
Different Cell Types ◽  
Main Factor

Maintenance of the individual patterns of gene expression in different cell types is required for the differentiation and development of multicellular organisms. Expression of many genes is controlled by Polycomb (PcG) and Trithorax (TrxG) group proteins that act through association with chromatin. PcG/TrxG are assembled on the DNA sequences termed PREs (Polycomb Response Elements), the activity of which can be modulated and switched from repression to activation. In this study, we analyzed the influence of transcriptional read-through on PRE activity switch mediated by the yeast activator GAL4. We show that a transcription terminator inserted between the promoter and PRE doesnt prevent switching of PRE activity from repression to activation. We demonstrate that, independently of PRE orientation, high levels of transcription fail to dislodge PcG/TrxG proteins from PRE in the absence of a terminator. Thus, transcription is not the main factor required for PRE activity switch.

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