ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

Hits per page

hits 1 - 3 | 3 hits

Sorting

Electronic Resource

Differential effects of superoxide, hydrogen peroxide, and hydroxyl radical on intracellular calcium in human endothelial cells (1995)

Dreher, D. ; Junod, A. F.

New York, NY [u.a.] : Wiley-Blackwell

Journal of Cellular Physiology 162 (1995), S. 147-153

add to mindlist on the mindlist

Details

ISSN: 0021-9541

Keywords: Life and Medical Sciences ; Cell & Developmental Biology

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Biology , Medicine

Notes: Changes in intracellular Ca2+ homeostasis are thought to contribute to cell dysfunction in oxidative stress. The hypoxanthine-xanthine oxidase system (X-XO) mobilizes Ca2+ from intracellular stores and induces a marked rise in cytosolic calcium in different cell types. To identify the reactive O2 species involved in the disruption of calcium homeostasis by X-XO, we studied the effect of X-XO on [Ca2+]i by spectrofluorimetry with fura-2 in human umbilical vein endothelial cells (HUVEC). The [Ca2+]i response to X-XO was essentially diminished by superoxide dismutase (SOD) (200 U/ml) and catalase (CAT) (200 U/ml), which scavenge the superoxide anion, O2-, or H2O2, respectively. The [Ca2+]i increase stimulated by 10 nmol H2O2/ml/min, generated from the glucose-glucose oxidase system, or 10 μM H2O2, given as bolus, was about a third of that induced by X-XO (10 nmol O2-/ml/min) but was comparable to that induced by X-XO in the presence of SOD. The X-XO - stimulated [Ca2+]i increase was significantly reduced by 100 μM o-phenanthroline, which inhibits the iron-catalysed formation of the hydroxyl radical. On the other hand, the [Ca2+]i response to low dose X-XO (1 nmol O2-/ml/min) was markedly enhanced in the presence of 1 μM H2O2, which itself had no effect on [Ca2+]i. More than 50% of this synergistic effect was prevented by o-phenanthroline. These results indicate that the effect of X-XO on calcium homeostasis appears to result from an interaction of O2- and H2O2, which could be explained by the formation of the hydroxyl radical. © 1995 Wiley-Liss, Inc.

Additional Material: 4 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/jcp.1041620118

Permalink

	Location	Call Number	Expected	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

Effects of oxidative stress and Ca2+ agonists on molecular chaperones in human umbilical vein endothelial cells (1995)

Dreher, Don ; Vargas, J. Reynaldo ; Hochstrasser, Denis F. ; [et al.]

Weinheim : Wiley-Blackwell

Electrophoresis 16 (1995), S. 1205-1214

add to mindlist on the mindlist

Details

ISSN: 0173-0835

Keywords: Two-dimensional polyacrylamide gel electrophoresis ; Human umbilical vein endothelial cells ; Xanthine oxidase ; Glucose regulated protein ; Heat shock protein ; Stress protein expression ; Chemistry ; Biochemistry and Biotechnology

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Biology , Chemistry and Pharmacology

Notes: Endothelial cell dysfunction is a key factor in oxidative stress-related pathology. Disruption of Ca2+ homeostasis is thought to be responsible for much of the endothelial cell dysfunction in oxidative stress. The expression of molecular chaperones (MC), which stabilize protein structures in normal and in stress conditions, reflects the Ca2+ -dependent and -independent stress effects in the different cell compartments. By two-dimensional (2-D) gel electrophoresis, combined with immunoblotting or microsequencing, we have identified 12 major MC in human umbilical vein endothelial cells (HUVEC): (i) the endoplasmic reticulum-located MC GRP78, GRP94, protein disulfide isomerase, and calreticulin; (ii) the mitochondrial MC HSP65 and GRP75; and (iii) the cytosolic/nuclear MC HSP27, HSC70, HSP70, HSP90, cyclophilin, and ubiquitin. To differentiate oxidative stress- and Ca2+ -mediated effects, HUVEC were exposed to 1) xanthine oxidase plus hypoxanthine to generate oxidative stress, 2) ionomycin plus ethylene glycol-bis(β-aminoethylether)-N,N,N′,N′-tetraacetic acid (EGTA) to deplete intracellular Ca2+ stores, or 3) thrombin to increase cytosolic Ca2+. De novo protein synthesis after exposure was quantified by the incorporation of [35S]methionine. Image processing with the MELANIE system was used to create and compare the 2-D maps of [35S]methionine-labeled proteins under conditions 1)-3) with those of the controls. In a total of 24 2-D gels, 9 different MC were detected in at least 5 out 6 experimental replicates and were subjected to numeric analysis. The statistics showed a 〉 10% increase in GRP78 (p 〈 0.05), HSP27, cyclophilin, and ubiquitin after oxidative stress. Ionomycin plus EGTA influenced the expression of GRP78 (p 〈 0.01), cyclophilin, and ubiquitin in the same direction, but in addition increased GRP94 (p 〈 0.01) and calreticulin. Thrombin upregulated calreticulin (p 〈 0.05), HSC70, and cyclophilin. In conclusion, the computer analysis of MC expression on 2-D maps under different stress conditions reveals a differential correlation between the oxidative stress and the depletion of Ca2+ stores in HUVEC.

Additional Material: 4 Ill.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1002/elps.11501601201

Permalink