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Lysophosphatidic acid depletes intracellular calcium stores different from those mediating capacitative calcium entry in C6 rat glioma cells
Author(s) -
Hildebrandt JanPeter,
Hildebrandt Petra
Publication year - 1997
Publication title -
glia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.954
H-Index - 164
eISSN - 1098-1136
pISSN - 0894-1491
DOI - 10.1002/(sici)1098-1136(199701)19:1<67::aid-glia7>3.0.co;2-7
Subject(s) - lysophosphatidic acid , calcium , biology , extracellular , microbiology and biotechnology , calcium in biology , cytosol , autotaxin , calcium signaling , phospholipase c , intracellular , purinergic receptor , thapsigargin , endocrinology , biochemistry , medicine , receptor , signal transduction , enzyme
Abstract Lysophosphatidic acid (LPA) functions as an extracellular lipid mediator stimulating phospholipase C and affecting the structure of the cytoskeleton in several cell types. In rat glioma C6 cells, LPA mobilizes calcium from intracellular calcium stores and reverts morphological changes induced by elevated cytosolic cAMP‐concentrations. Here we show that LPA‐stimulation of C6 cells loaded with the calcium‐sensitive fluorescent dye indo‐1 results in calcium release from a subset of intracellular calcium stores that are not sensitive to the tumor promoter thapsigargin and do not overlap with calcium stores depleted during purinergic receptor stimulation with ATP. Furthermore, depletion of LPA‐sensitive calcium stores does not induce capacitative calcium entry from the extracellular space into the cytosol to the same extent as ATP. These results indicate that inositol phosphate signaling induced by LPA or ATP may differ in kinetics or in spatial organisation within the cell. This may represent a possible explanation for the previous observation that only LPA, but not other calcium‐mobilizing agonists, reverts cAMP‐induced changes in the cytoskeletal organization in C6 cells. GLIA 19:67–73, 1997. © 1997 Wiley‐Liss, Inc.