The Relationship between Intracellular pH and Heat Sensitivity in a Thermoresistant Cell Line

1996 ◽  
Vol 145 (2) ◽  
pp. 144 ◽  
Author(s):  
F-F. Liu ◽  
M. D. Sherar ◽  
R. P. Hill
Keyword(s):  
Cell Line ◽  
Intracellular Ph ◽  
Heat Sensitivity ◽  
The Relationship

Intracellular acidification induces apoptosis by stimulating ICE-like protease activity

1997 ◽  
Vol 110 (5) ◽  
pp. 653-661 ◽  
Author(s):  
I.J. Furlong ◽  
R. Ascaso ◽  
A. Lopez Rivas ◽  
M.K. Collins
Keyword(s):  
Cell Line ◽  
Dna Fragmentation ◽  
Intracellular Ph ◽  
Protease Activity ◽  
Intracellular Acidification ◽  
Over Expression ◽  
Protease Activation ◽  
Dependent Cell ◽  
A Cell ◽  
Ph Decrease

ICE-like protease activation and DNA fragmentation are preceded by a decrease in intracellular pH (pHi) during apoptosis in the IL-3 dependent cell line BAF3. Acidification occurs after 7 hours in cells deprived of IL-3 and after 4 hours when cells are treated with etoposide, close to the time of detection of ICE-like protease activity. Increasing extracellular pH reduces ICE-like protease activation and DNA fragmentation. Bcl-2 over-expression both delays acidification and inhibits ICE-like protease activation. Generation of a rapid intracellular pH decrease, using the ionophore nigericin, induces ICE-like protease activation and apoptosis. ZVAD, a cell permeable inhibitor of ICE-like proteases, does not affect acidification but inhibits apoptosis induced by IL-3 removal or nigericin treatment. These data suggest that intracellular acidification triggers apoptosis by directly or indirectly activating ICE-like proteases.

H+-linked transport of salicylic acid, an NSAID, in the human trophoblast cell line BeWo

2002 ◽  
Vol 282 (5) ◽  
pp. C1064-C1075 ◽  
Author(s):  
Akiko Emoto ◽  
Fumihiko Ushigome ◽  
Noriko Koyabu ◽  
Hiroshi Kajiya ◽  
Koji Okabe ◽  
...  
Keyword(s):  
Salicylic Acid ◽  
Lactic Acid ◽  
Cell Line ◽  
Intracellular Ph ◽  
Trophoblast Cell ◽  
Monocarboxylate Transporter ◽  
Human Trophoblast ◽  
Inflammatory Drugs ◽  
Ph Dependent ◽  
Trophoblast Cell Line

We investigated the transport of salicylic acid and l-lactic acid across the placenta using the human trophoblast cell line BeWo. We performed uptake experiments and measured the change in intracellular pH (pHi). The uptakes of [14C]salicylic acid andl-[14C]lactic acid were temperature- and extracellular pH-dependent and saturable at higher concentrations. Both uptakes were also reduced by FCCP, nigericin, and NaN3. Various nonsteroidal anti-inflammatory drugs (NSAIDs) strongly inhibited the uptake of l-[14C]lactic acid. Salicylic acid and ibuprofen noncompetitively inhibited the uptake ofl-[14C]lactic acid. α-Cyano-4-hydroxycinnamate (CHC), a monocarboxylate transporter inhibitor, suppressed the uptake ofl-[14C]lactic acid but not that of [14C]salicylic acid. CHC also suppressed the decrease of pHi induced by l-lactic acid but had little effect on that induced by salicylic acid or diclofenac. These results suggest that NSAIDs are potent inhibitors of lactate transporters, although they are transported mainly by a transport system distinct from that for l-lactic acid.

Effect of short-chain fatty acids on paracellular permeability in Caco-2 intestinal epithelium model

1997 ◽  
Vol 272 (4) ◽  
pp. G705-G712 ◽  
Author(s):  
J. M. Mariadason ◽  
D. H. Barkla ◽  
P. R. Gibson
Keyword(s):  
Fatty Acids ◽  
Cell Line ◽  
Antigen Expression ◽  
Short Chain Fatty Acids ◽  
Paracellular Permeability ◽  
Short Chain ◽  
Differentiating Agents ◽  
The Relationship ◽  
Chain Fatty Acids

Control of paracellular permeability in the colonic epithelium is fundamental to its functional competence. This study examines the relationship between physiologically relevant short-chain fatty acids (SCFAs) and paracellular permeability using the Caco-2 cell line model. Butyrate induced a concentration-dependent, reversible increase in transepithelial resistance (TER) that was maximal after 72 h. Butyrate (2 mM) increased TER by 299 +/- 69% (mean +/- SE; n = 5; P < 0.05; t-test) and reduced mannitol flux to 52 +/- 11% (P < 0.05) of control. The effect of butyrate was dependent on protein synthesis and gene transcription but not dependent on its oxidation or activation of adenosine 3',5'-cyclic monophosphate. The other SCFAs, propionate and acetate, also induced a concentration-dependent increase in TER. The effect of butyrate paralleled changes in cellular differentiation, because alkaline phosphatase activity, carcinoembryonic antigen expression, and dome formation were increased. Furthermore, other differentiating agents (dimethyl sulfoxide and retinoic acid) also increased TER. Thus SCFAs reduce paracellular permeability in the Caco-2 cell line, possibly by promotion of a more differentiated phenotype. If such an effect occurs in vivo, it may have ramifications for the biology and pathobiology of colonic mucosa.

The relationship between CD86/CD54 expression and THP-1 cell viability in an in vitro skin sensitization test – human cell line activation test (h-CLAT)

2008 ◽  
Vol 25 (2) ◽  
pp. 109-126 ◽  
Author(s):  
Hitoshi Sakaguchi ◽  
Takao Ashikaga ◽  
Masaaki Miyazawa ◽  
Nanae Kosaka ◽  
Yuichi Ito ◽  
...  
Keyword(s):  
Cell Viability ◽  
Cell Line ◽  
Human Cell ◽  
Human Cell Line ◽  
Skin Sensitization ◽  
Activation Test ◽  
The Relationship

scholarly journals Acid phosphatase activity in mononuclear phagocytes and the U937 cell line: monocyte-derived macrophages express tartrate-resistant acid phosphatase

Blood ◽  
1986 ◽  
Vol 67 (3) ◽  
pp. 729-734
Author(s):  
RG Snipes ◽  
KW Lam ◽  
RC Dodd ◽  
TK Gray ◽  
MS Cohen
Keyword(s):  
Acid Phosphatase ◽  
Cell Line ◽  
Gel Electrophoresis ◽  
U937 Cell ◽  
Colorimetric Assay ◽  
Mononuclear Phagocytes ◽  
Tartrate Resistant Acid Phosphatase ◽  
U937 Cells ◽  
Phagocytic Cells ◽  
The Relationship

Tartrate-resistant acid phosphatase (TRAcP) is used as a marker for osteoclasts, which are believed to be derived from phagocytic cells or phagocyte stem cell precursors. To further investigate the relationship between monocytic phagocytes and osteoclasts, acid phosphatase (AcP) activity was measured by three different techniques in human peripheral blood monocytes, monocyte-derived macrophages, and the U937 cell line. We found that cytochemistry and gel electrophoresis led to similar results, but that the colorimetric assay was inconsistent. Normal human peripheral monocytes expressed both tartrate-sensitive and -resistant AcP. In culture these cells formed polykaryons and expressed TRAcP activity that was further identified as an isoenzyme associated with bone tissue. In contrast, the U937 cells did not express TRAcP activity as measured by gel electrophoresis. Both U937 cells and monocytes possess material that interferes with interpretation of the colorimetric assay of AcP. The presence of TRAcP in monocyte-derived macrophages further supports the relationship between phagocytic cells and bone osteoclasts.

scholarly journals Soluble neutral and acid maltases in the suckling-rat intestine. The effect of cortisol and development

1974 ◽  
Vol 144 (2) ◽  
pp. 281-292 ◽  
Author(s):  
G Galand ◽  
G G Forstner
Keyword(s):  
Molecular Weight ◽  
Gradient Centrifugation ◽  
Heat Sensitivity ◽  
Adult Rats ◽  
Ph Optimum ◽  
Maltase Activity ◽  
Acid Maltase ◽  
Membrane Bound ◽  
Sepharose 4B ◽  
The Relationship

The 100000g supernatants from 13-day-old suckling-rat intestinal homogenates contained 43.5% of the total intestinal maltase activity, compared with 7.1% in weaned adult rats aged 40 days. The soluble maltase activity was separated on Sepharose 4B into two quantitatively equal fractions at pH6.0, one containing a maltase with a neutral pH optimum and the other a maltase with an acid pH optimum. The neutral maltase was shown to be a maltase–glucoamylase identical with membrane-bound maltase–glucoamylase in molecular weight, heat-sensitivity, substrate specificity, Km for maltose and Ki for Tris. The soluble enzyme was induced by cortisol, but the ratio of the soluble to bound enzyme fell during induction. Solubility of the neutral maltase was not accounted for by the action of endogenous proteinases under the preparative conditions used. It is postulated that the soluble neutral maltase is a membrane-dissociated form of the bound enzyme and that the relationship between these two forms is modulated by cortisol. The acid maltase generally resembled acid maltase of liver, muscle and kidney. It was shown to be a maltase–glucoamylase with optimal activity at pH3.0, and molecular weight of 136000 by density-gradient centrifugation. At pH3.0 its Km for maltose was 1.5mm. It was inhibited by turanose (Ki=7.5mm) and Tris (Ki=5.5mm) but not by p-chloromercuribenzoate or EDTA. Some 55% of its activity was destroyed by heating at 50°C for 10min. The acid maltase closely resembled β-glucuronidase and acid β-galactosidase in its distribution in the intestine, response to tissue homogenization in various media, and decrease in activity with cortisol treatment and weaning, indicating that it was a typical lysosomal enzyme concentrated in the ileum.

K(+)-induced alkalinization in mouse cerebral astrocytes mediated by reversal of electrogenic Na(+)-HCO3- cotransport

1994 ◽  
Vol 267 (6) ◽  
pp. C1633-C1640 ◽  
Author(s):  
N. Brookes ◽  
R. J. Turner
Keyword(s):  
Intracellular Ph ◽  
Primary Cultures ◽  
Atmospheric Co2 ◽  
Disulfonic Acid ◽  
Free Solution ◽  
High Affinity ◽  
Alkaline Shift ◽  
Net Flux ◽  
K Concentration ◽  
The Relationship

Raising extracellular K+ concentration ([K+]o) induces an alkaline shift of intracellular pH (pHi) in astrocytes. The mechanism of this effect was examined using the fluorescent pHi indicator 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein in primary cultures of mouse cerebral astrocytes. Raising [K+]o from 3 to 12 mM increased pHi by 0.28 pH units in 26 mM HCO(3-)-buffered solution. In nominally HCO(3-)-free solution (containing approximately 95 microM HCO3-), the alkalinization fell to 0.21 pH units and further to 0.08 pH units on removal of atmospheric CO2, suggesting a process with high affinity for HCO3-. This effect was Na+ dependent, Cl- independent, and inhibited by 0.5 mM 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid, indicating the involvement of Na(+)-HCO3- cotransport. The relationship between pHi and log[K+]o was found to be linear and to predict a stoichiometry of at least two HCO3- transported with each Na+. After removal of exogenous CO2/HCO3-, the direction of changes in pHi elicited by adding 1 mM HCO3- showed that net flux of HCO3- via the Na(+)-HCO3- cotransporter was outward at rest and was reversed by depolarization.

Relationship Between Freezing Rate, Ultrastructure and Recovery in a Human Diploid Cell Line

1974 ◽  
Vol 15 (2) ◽  
pp. 419-427
Author(s):  
D. J. BEADLE ◽  
L. W. HARRIS
Keyword(s):  
Cell Line ◽  
Structural Damage ◽  
Diploid Cell ◽  
Freezing Rate ◽  
Human Diploid Cell ◽  
Simple Correlation ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Diploid Cell Line ◽  
The Relationship

The relationship between freezing rate, ultrastructure and recovery in a human diploid cell line has been studied by freezing cells at rates that are known to give high and low recoveries and examining them immediately after thawing. Some correlation was found between structural damage and recovery. The main types of damage observed were loss of cytoplasm and nucleoplasm, indicating disruption of cellular membranes, and swelling of subcellular organelles due to osmotic changes during the freeze-thaw cycle. No simple correlation was found between freezing rate and structural damage. In the absence of a cryoprotectant both rapid and slow freezing produced similar types and amounts of damage resulting in low recovery. In the presence of 10% dimethylsulphoxide, however, slowly frozen cells showed few signs of damage and recovery was high. DMSO had no such protective effect on rapidly frozen cells.

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