Sialosyl cholesterol induces morphological and biochemical differentiations of glioblasts without intracellular cyclic AMP level rise.
Synthesized sialosyl cholesterols, alpha- and beta-D-N-acetylneuraminyl cholesterols (alpha-SC and beta-SC), induced the morphological conversion of normal rat glioblasts from a flat epithelioid morphology to an astrocytic process-bearing (stellate) morphology resembling the conversion by glia maturation factor (GMF). The stellogenic effects were rapid and detectable within 1 h after drug stimulation, and irrelevant to the intracellular cyclic adenosine monophosphate (cAMP) levels. The morphological alteration was ascertained by the fluorescence-visualization of cytoskeletons: alpha-SC elicited the reorganization of GFA protein network to the formation of bundles, the destruction of stress fiber, and the redistribution as plasmalemmal constituents. alpha-SC also evoked biological differentiations represented by an elevation of glial marker proteins, S-100 protein and GFA protein. The results provide a possibility that SC incorporated into plasma membrane may cause morphologically and biochemically astrocyte-like differentiations of glioblast through the alteration of membrane characteristics, the cytoskeletal anchorages to the membrane, the affinity of receptors, and/or the postreceptor responses distinct from cAMP-production system.
Kato
T
T
Department of Biochemistry, Nagoya City University Medical School, Japan.
Ito
J
J
Tanaka
R
R
Suzuki
Y
Y
Hirabayashi
Y
Y
Matsumoto
M
M
Ogura
H
H
Kato
K
K
D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D002452:Cell Count; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D002788:Cholesterol Esters / Q000494:pharmacology*; D000242:Cyclic AMP / Q000378:metabolism*; D004261:DNA Replication / Q000187:drug effects; D009414:Nerve Growth Factors / Q000494:pharmacology; D009457:Neuroglia / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D009473:Neuronal Plasticity / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D012794:Sialic Acids / Q000494:pharmacology*; D013997:Time Factors
D002788:Cholesterol Esters; D009414:Nerve Growth Factors; D012794:Sialic Acids; C055195:N-acetylneuraminyl cholesterol; D000242:Cyclic AMP