Journal archive > 2009 > N 1 January-February

ANALYSIS OF SIGNALING PATHWAYS ACTIVATED BY NICOTINIC ACETYLCHOLINE
RECEPTORS IN В-LYMPHOCYTE-DERIVED CELLS

D. M. Omelchenko, O. M. Kalashnik, L. M.?Koval, M. V. Skok, S. V. Komisarenko

Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv;
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The expression of nicotinic acetylcholine receptors (nAChRs) in the chicken pre-B-lymphoma DT40 cell line was investigated. DT40 cells were shown to express at least ?7-containing nAChRs; their amount increased upon incubation with 10?µM nicotine. Addition of 10 µM choline favoured the inclusion of 3-[4.5dimethylthiazol-2-yl]-2.5-diphenyltetrazolium bromide (MTT); the effect of choline was inhibited by 2.5-25 nM methyllicaconitine (MLA) or 10-100 nM ?-cobratoxin indicating the ?7 nAChR role in maintaining the proliferative potential of DT40 cells. Nicotine and choline potentiated the effect of 0.5 µM ionomycin, which suppresses cell viability via Са2+ ions influx. Contrariwise, the suppressive effect of 1 µM hydrogen peroxide, mainly affecting cell mitochondria, was weakened by choline, but was increased by 2.5?nM MLA. MEK1/2 and PKC kinases activity was necessary for maintaining the proliferative potential of DT40 cells. MLA increased the effect of the MEK1/2 kinase inhibitor (U0126), while suppressive effect of MLA itself was decreased. The presence of CaMKII kinase inhibitor (KN-62) also decreased MLA effect. MLA favoured cell survival in the presence of PKC inhibitor (chelerythrine). These data indicate that MEK1/2 and CaMKII kinases are involved in ?7-containing nAChR signaling in DT40 cells and that PKC plays a key role in this process.

Key words: nicotinic acetylcholine receptor, proliferation, DT40 cell line, MEK 1/2, PKC.

The original article in Ukrainian is available for download in PDF format.

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