PubMed Health⌕ Search

PubMed · 12618262

Copper ions dynamically regulate beta3 integrin subunit expression in Ishikawa cells.

Abstract

Copper intrauterine device (IUD) users have a reduced expression of beta3 integrin subunit during the implantation window. This integrin has been found to be a uterine marker for implantation. In order to verify if copper ions are involved in this reduction, beta3 integrin subunit expression was assessed in an in vitro model. The beta3 integrin subunit expression was determined by flow cytometry in the presence of copper D-gluconate and/or epidermal growth factor (EGF). The mean percentages of positive beta3 integrin subunit cells under different culture conditions were: 4.7 +/- 0.29 (mean +/- SEM) in controls; 8.6 +/- 0.59 in the presence of copper; 13.4 +/- 0.05 in the presence of EGF and 20.8 +/- 0.36 in the presence of EGF+copper (analysis of variance, p < 0.0001). Copper D-gluconate up-regulates beta3 integrin subunit expression in vitro both in the presence and absence of EGF. The differences between in vivo and in vitro results should be investigated and may represent interference by other factors such as the inflammatory process associated with the presence of IUDs.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

R Savaris, J A B Chies. 2003. Copper ions dynamically regulate beta3 integrin subunit expression in Ishikawa cells.. https://doi.org/10.1016/s0010-7824(02)00511-5

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Roles of the histidine and tryptophan side chains in the M2 proton channel from influenza A virus.

The M2 protein form influenza A virus forms a tetrameric ion channel, which enables proton passage across biological membranes when the N-terminal side is acidified. Among the amino acid residues in the transmembrane domain of the M2 protein, His37 and Trp41 are essential for the pH-regulated proton conductance. Current knowledge about the structures and interactions of His37 and Trp41 suggests a model for the M2 ion channel, in which the channel is closed by a network of His37 hydrogen bonds at neutral pH and is opened by a His37-Trp41 cation-pi interaction at acidic pH.

Cations↗

Oxidation of thioanisole and p-methoxythioanisole by lignin peroxidase: kinetic evidence of a direct reaction between compound II and a radical cation.

The reaction of H2O2 with thioanisole and p-methoxythioanisole catalysed by lignin peroxidase from Phanerochaete chrysosporium has been studied spectrophotometrically under turnover and single turnover conditions with a stopped-flow apparatus. Pre-formed lignin peroxidase compounds I and II are each able to react with the sulphides to form a sulphide radical cation. The radical cation is then converted into the sulphoxide either by reaction with the medium or by reaction with compound II. This is the first report of a direct reaction between compound II and the substrate radical cation. With thioanisole, significant enantiomeric selectivity and high oxygen incorporation in the sulphoxide are obtained because compound II is preferentially reduced by the enzyme-bound thioanisole radical cation compared with the neutral substrate. By contrast, with p-methoxythioanisole, the data imply formation of an intermediate ternary complex comprising compound II, radical cation and neutral substrate, such that a chain of electron transfer reactions starting from neutral molecule and progressing to oxidized haem via substrate radical cation is facilitated, yielding the native enzyme and two molecules of p-methoxythioanisole radical cation as products. The reactions of compounds I and II with sulphides imply flexing of the apoprotein moiety during catalysis.

Cations↗

Hypertonic activation of a non-selective cation conductance in HeLa cells and its contribution to cell volume regulation.

In whole-cell recordings on single HeLa cells, the hypertonic activation of a cation conductance with a selectivity ratio P(Na):P(Li):P(K):P(Cs):P(NMDG):P(Ca):P(Cl) of 1.00:0.86:0.84:0.56:0.10:0.07:0.15 was observed. This (non-selective) cation conductance was reduced to 59 and 30% of maximal stimulation by Gd(3+) and flufenamate, respectively, but it was insensitive to amiloride (with each compound applied at 100 microm/l). As was determined by the Coulter counter technique, the cation conductance was the main mechanism of regulatory volume increase (RVI) in HeLa cells. Whereas a significant contribution of Na(+)/H(+) antiport was also detectable, Na(+)-K(+)-2Cl(-) symport most likely did not contribute to RVI.

Cations↗