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Incorporation of N ‐propanoylneuraminic acid leads to calcium oscillations in oligodendrocytes upon the application of GABA
Author(s) -
Schmidt Carolin,
Ohlemeyer Carsten,
Kettenmann Helmut,
Reutter Werner,
Horstkorte Rüdiger
Publication year - 2000
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(00)01868-8
Subject(s) - calcium , chemistry , biochemistry , oligodendrocyte , glycoconjugate , sialic acid , glycolipid , nap , microbiology and biotechnology , astrocyte , galactocerebroside , neuraminic acid , biology , myelin , endocrinology , central nervous system , neuroscience , organic chemistry
Sialylation of glycoproteins and glycolipids plays an important role during development, regeneration and pathogenesis. It has been shown that unnatural sialylation within glial cell cultures can have distinct effects on their proliferation and antigenic profiles. These cultures metabolize N ‐propanoylmannosamine ( N ‐propanoylneuraminic acid precursor=P‐NAP), a synthetic non‐physiological precursor of neuraminic acid, resulting in the expression of N ‐propanoylneuraminic acid in glycoconjugates of their cell membranes [Schmidt, C., Stehling, P., Schnitzer, J., Reutter, W. and Horstkorte, R. (1998) J. Biol. Chem. 273, 19146–19152]. To determine whether these biochemically engineered sialic acids influence calcium concentrations in cells of the oligodendrocyte lineage, mixed glial cultures of oligodendrocytes growing on top of an astrocyte monolayer were exposed to glutamate, histamine, adrenaline, γ‐aminobutyric acid (GABA), high potassium (high K + ) and ATP. Calcium responses in P‐NAP‐treated oligodendrocytes were determined by confocal microscopy with the calcium indicator fluo‐3 AM, and compared with control cultures. We showed that P‐NAP differentially modulated the calcium responses of individual oligodendrocytes when GABA was applied. GABA induced calcium oscillations with up to four spikes per min in 60% of oligodendrocytes when treated with P‐NAP.