Roles of calcium in aggregation of rat ascites hepatoma cells by cell surface-associated adhesive factor

1984 ◽  
Vol 66 (1) ◽  
pp. 367-382
Author(s):  
S. Kurano ◽  
M. Ishida ◽  
Y. Ishimaru

Our previous studies have shown that a cell surface-associated adhesive factor (AF), separated from rat ascites hepatoma AH136B cells of a differentiated type and highly purified by chromatography, induces not only aggregation of dissociated AH136B cells or rat ascites hepatoma AH109A cells of an undifferentiated type but also adhesiveness characterized by the development of junctional complexes; the AF-induced aggregation of the cells was Ca2+-dependent. Further analysis of the roles of Ca2+ in cell aggregation was performed using AH109A cells (present as single cells in vivo). (1) AF clearly enhanced 45Ca uptake by the cells; (2) calmodulin was isolated from the cells; (3) calmodulin inhibitor, W-7 (N-(6-amino-hexyl)-5-chloro-1-naphthalenesulphonamide), strongly inhibited aggregation of the cells; (4) W-7 also inhibited the clustering or capping of AF-binding sites on the cell surface; (5) binding of 125I-labelled AF to the cells was independent of Ca2+ concentration; (6) binding of 125I-labelled AF to AF-conjugated beads was not observed, independently of the presence of Ca2+. These findings suggest that Ca2+ and Ca2+-activated calmodulin may play a key role in the process of aggregation of the cells by controlling the microfilament components and that Ca2+ may not be involved either in the interactions between AF and its cellular receptor or in linkages of AF molecules.

1984 ◽  
Vol 71 (1) ◽  
pp. 95-109
Author(s):  
R. Hattori ◽  
Y. Ishimaru ◽  
R. Kurano ◽  
H. Hayashi

As previously described, a cell surface-associated adhesive factor (AF) was separated from differentiated rat ascites hepatoma AH136B cells (forming cell islands in vivo) and highly purified by chromatography. AF synthesis by the cells was investigated by means of ultrastructural immunoperoxidase cytochemistry. Its synthesis and localization in vivo were observed in the perinuclear spaces, the rough endoplasmic reticulum, the Golgi apparatus, the smooth-membranous vesicles, and the contact region of basolateral cell surfaces of the cells in the islands, and also in the intercellular spaces. No AF synthesis was detectable in the nucleus, the free ribosomes, the mitochondria or the apical non-contacting cell surfaces. Similar features of AF synthesis and localization were also induced by dissociated AH136B cells in vitro. Upon adhesion of such recovered cells, AF was also localized at the contact surface of the adjacent cells, but not at the non-contacting free surface.


2019 ◽  
Author(s):  
Jiefu Li ◽  
Shuo Han ◽  
Hongjie Li ◽  
Namrata D. Udeshi ◽  
Tanya Svinkina ◽  
...  

SUMMARYMolecular interactions at the cellular interface mediate organized assembly of single cells into tissues, and thus govern the development and physiology of multicellular organisms. Here, we developed a cell-type-specific, spatiotemporally-resolved approach to profile cell-surface proteomes in intact tissues. Quantitative profiling of cell-surface proteomes of Drosophila olfactory projection neurons (PNs) in pupae and adults revealed a global down-regulation of wiring molecules and an up-regulation of synaptic molecules in the transition from developing to mature PNs. A proteome-instructed in vivo screen identified 20 new cell-surface molecules regulating neural circuit assembly, many of which belong to evolutionarily conserved protein families not previously linked to neural development. Genetic analysis further revealed that the lipoprotein receptor LRP1 cell-autonomously controls PN dendrite targeting, contributing to the formation of a precise olfactory map. These findings highlight the power of temporally-resolved in situ cell-surface proteomic profiling in discovering new regulators of brain wiring.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jonas Mattisson ◽  
Marcus Danielsson ◽  
Maria Hammond ◽  
Hanna Davies ◽  
Caroline J. Gallant ◽  
...  

AbstractMosaic loss of chromosome Y (LOY) in immune cells is a male-specific mutation associated with increased risk for morbidity and mortality. The CD99 gene, positioned in the pseudoautosomal regions of chromosomes X and Y, encodes a cell surface protein essential for several key properties of leukocytes and immune system functions. Here we used CITE-seq for simultaneous quantification of CD99 derived mRNA and cell surface CD99 protein abundance in relation to LOY in single cells. The abundance of CD99 molecules was lower on the surfaces of LOY cells compared with cells without this aneuploidy in all six types of leukocytes studied, while the abundance of CD proteins encoded by genes located on autosomal chromosomes were independent from LOY. These results connect LOY in single cells with immune related cellular properties at the protein level, providing mechanistic insight regarding disease vulnerability in men affected with mosaic chromosome Y loss in blood leukocytes.


2002 ◽  
Vol 1 (5) ◽  
pp. 319-327 ◽  
Author(s):  
M. P. Rols ◽  
M. Golzio ◽  
B. Gabriel ◽  
J. Teissié

Electric field pulses are a new approach for drug and gene delivery for cancer therapy. They induce a localized structural alteration of cell membranes. The associated physical mechanisms are well explained and can be safely controlled. A position dependent modulation of the membrane potential difference is induced when an electric field is applied to a cell. Electric field pulses with an overcritical intensity evoke a local membrane alteration. A free exchange of hydrophilic low molecular weight molecules takes place across the membrane. A leakage of cytosolic metabolites and a loading of polar drugs into the cytoplasm are obtained. The fraction of the cell surface which is competent for exchange is a function of the field intensity. The level of local exchange is strongly controlled by the pulse duration and the number of successive pulses. The permeabilised state is long lived. Its lifetime is under the control of the cumulated pulse duration. Cell viability can be preserved. Gene transfer is obtained but its mechanism is not a free diffusion. Plasmids are electrophoretically accumulated against the permeabilised cell surface and form aggregates due to the field effect. After the pulses, several steps follow: translocation to the cytoplasm, traffic to the nucleus and expression. Molecular structural and metabolic changes in cells remain mostly poorly understood. Nevertheless, while most studies were established on cells in culture ( in vitro), recent experiments show that similar effects are obtained on tissue ( in vivo). Transfer remains controlled by the physical parameters of the electrical treatment.


1988 ◽  
Vol 90 (4) ◽  
pp. 683-689 ◽  
Author(s):  
A. Kimura ◽  
T. Kawaguchi ◽  
T. Ono ◽  
A. Sakuma ◽  
Y. Yokoya ◽  
...  

Two variants (74AD and 74FL) established from rat ascites hepatoma AH7974 were examined for the production of glycosaminoglycans in culture. There was no difference between the adhesive (74AD) and the floating (74FL) variants in quantity of glycosaminoglycans produced by their cultivation in minimum essential medium supplemented with 10% foetal calf serum. However, they were distinctly different in the distribution patterns of heparan sulphate. In 74FL, about 70% of total heparan sulphate was found in the culture medium in soluble form, whereas in 74AD, only 7% was found in the medium and the rest was in the cell-substratum complex. In a serum-free medium, 74AD cells grew without adhering to the substratum. After cultivation, more than 90% of total heparan sulphate was found in the cell-associated fractions and the rest in the substratum fractions. No heparan sulphate was detected in the culture medium. On the other hand, 74FL cells released heparan sulphate to the serum-free medium as much as to the serum-containing medium. The increase in amount of heparan sulphate in the culture medium of 74FL cells was supposed to be caused by failure of the cells to deposit heparan sulphate at the cell surface and not caused by increased production. Cell-substratum adhesion mechanisms involving cell surface heparan sulphate (heparan sulphate proteoglycan) and some serum intermediate(s) are discussed for 74AD cells.


1994 ◽  
Vol 12 (3) ◽  
pp. 203-212 ◽  
Author(s):  
Takanori Kawaguchi ◽  
Tomohisa Ono ◽  
Hironao Wakabayashi ◽  
Seiji Igarashi

1984 ◽  
Vol 160 (1) ◽  
pp. 341-346 ◽  
Author(s):  
E S Vitetta ◽  
R J Fulton ◽  
J W Uhr

In vitro killing of the human Daudi cell line by either univalent [F(ab')] or divalent (IgG) forms of rabbit anti-human Ig (RAHIg) coupled to ricin A chain can be specifically potentiated by a "piggyback" treatment with ricin B chain coupled to goat anti-rabbit Ig (GARIg). When cells are treated with univalent immunotoxin (IT) [F(ab') RAHIg-A] and then cultured, IT can be detected on the cell surface for at least 5 h, since GARIg-B can still enhance killing at this time. These results provide a strategy for in vivo use of A chain- and B chain-containing IT.


1987 ◽  
Vol 15 (6) ◽  
pp. 1109-1109 ◽  
Author(s):  
F. S. STEVEN ◽  
H. JACKSON

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