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Biomodulatory role of ceramide in basic fibroblast growth factor‐induced proliferation of cerebellar astrocytes in primary culture
Author(s) -
Riboni Laura,
Viani Paola,
Bassi Rosaria,
Stabilini Angela,
Tettamanti Guido
Publication year - 2000
Publication title -
glia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.954
H-Index - 164
eISSN - 1098-1136
pISSN - 0894-1491
DOI - 10.1002/1098-1136(200011)32:2<137::aid-glia30>3.0.co;2-2
Subject(s) - ceramide , biology , basic fibroblast growth factor , lipid signaling , microbiology and biotechnology , cell growth , astrocyte , signal transduction , fibroblast , growth factor , cell culture , endocrinology , medicine , biochemistry , central nervous system , receptor , apoptosis , genetics
To evaluate the role of ceramide in glial growth, primary cultures of quiescent astrocytes from rat cerebellum were stimulated to proliferate by mitogenic doses of basic fibroblast growth factor (bFGF). Parallel to the bFGF mitogenic effect was a marked, and persistent, decrease in cellular ceramide levels. Both in vitro and in culture metabolic studies have led us to exclude both sphingomyelinase and ceramidase involvement in ceramide level variation. Instead, we found evidence of a functional connection between the decrease in ceramide levels and astrocyte proliferation. In fact, cell growth in bFGF‐stimulated astrocytes was inhibited by exogenous ceramide and C2‐ceramide, maximal inhibition being obtained at a ceramide concentration of 5–10 μM. Under the same conditions, the dihydroderivatives of ceramides were without effect. Following ceramide treatment, the phosphorylation of the MAP kinase isoforms ERK1/2, key components in bFGF‐induced cell proliferation, was examined. The administration of antiproliferative doses of ceramide or C2‐ceramide, but not of their dihydroderivatives, resulted in a significant inhibition of ERK1/2 activation. In conclusion, our data indicate that the prompt modulation of ceramide levels by bFGF is an early step associated with the signaling pathways responsible for the mitogenic activity of bFGF in astrocytes. GLIA 32:137–145, 2000. © 2000 Wiley‐Liss, Inc.