TY - JOUR
T1 - Dissociation of the Stellate Morphology from Intracellular Cyclic AMP Levels in Cultured Rat Brain Astroglial Cells
T2 - Effects of Ganglioside GMl and Lysophosphatidylserine
AU - Facci, Laura
AU - Skaper, Stephen D.
AU - Levin, David L.
AU - Varon, Silvio
N1 - Copyright:
Copyright 2016 Elsevier B.V., All rights reserved.
PY - 1987/2
Y1 - 1987/2
N2 - Abstract: Secondary microcultures of newborn rat cerebrum astroglial (AG) cells, maintained in a serum‐free, chemically defined medium, were treated with various agents known to elevate intracellular cyclic AMP (cAMP) levels. Earlier studies had shown these drugs to induce a process‐bearing (stellate) morphology in the AG cells, a response that was antagonized by the presence of gangliosides. One millimolar dibutyryl cyclic AMP (dBcAMP), 10 μM forskolin, 12 nM cholera toxin, and 30 μM isoproterenol all raised intracellular cAMP levels, from basal values of 3 pmol/106 cells to 30–30,000 pmol/106 cells, depending on the agent tested. dBcAMP caused the greatest elevation, and forskolin the least. The timing and/or the level of the AMP response did not precisely correlate with those of the stella‐tion response. Values of ED50 with the four agents, as determined for the cAMP response, were always higher than stellation ED50 values in all treatments, and ED50 did not correlate with the maximal levels of cyclic AMP induced by the four agents. The capacity of ganglioside GMl to block the stellation response to the four agents was not accompanied by a similar capacity to block the cAMP responses. Lysophosphatidylserine (lysoPS) had the capacity to induce AG cell stellation as well, without altering the basal level of cAMP. Both lysoPS and gangliosides, therefore, may act directly on the cellular machinery underlying the stellation response without involving changes in intracellular AMP.
AB - Abstract: Secondary microcultures of newborn rat cerebrum astroglial (AG) cells, maintained in a serum‐free, chemically defined medium, were treated with various agents known to elevate intracellular cyclic AMP (cAMP) levels. Earlier studies had shown these drugs to induce a process‐bearing (stellate) morphology in the AG cells, a response that was antagonized by the presence of gangliosides. One millimolar dibutyryl cyclic AMP (dBcAMP), 10 μM forskolin, 12 nM cholera toxin, and 30 μM isoproterenol all raised intracellular cAMP levels, from basal values of 3 pmol/106 cells to 30–30,000 pmol/106 cells, depending on the agent tested. dBcAMP caused the greatest elevation, and forskolin the least. The timing and/or the level of the AMP response did not precisely correlate with those of the stella‐tion response. Values of ED50 with the four agents, as determined for the cAMP response, were always higher than stellation ED50 values in all treatments, and ED50 did not correlate with the maximal levels of cyclic AMP induced by the four agents. The capacity of ganglioside GMl to block the stellation response to the four agents was not accompanied by a similar capacity to block the cAMP responses. Lysophosphatidylserine (lysoPS) had the capacity to induce AG cell stellation as well, without altering the basal level of cAMP. Both lysoPS and gangliosides, therefore, may act directly on the cellular machinery underlying the stellation response without involving changes in intracellular AMP.
KW - Astroglial cells
KW - Cyclic AMP
KW - Gangliosides
KW - Morphology
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U2 - 10.1111/j.1471-4159.1987.tb04130.x
DO - 10.1111/j.1471-4159.1987.tb04130.x
M3 - Article
C2 - 3025372
AN - SCOPUS:0023154077
SN - 0022-3042
VL - 48
SP - 566
EP - 573
JO - Journal of neurochemistry
JF - Journal of neurochemistry
IS - 2
ER -