Stimulation of myelin proteolipid protein gene expression by eicosapentaenoic acid in C6 glioma cells.
In this study, the role of exogenous fatty acids in the regulation of proteolipid protein (PLP) gene expression was investigated using the following model culture system: C6 glioma cells expressing the green-fluorescent protein (eGFP) driven by different segments of PLP promoter. Eicosapentanoic acid (EPA; 20:5 n-3), but not arachidonic acid (AA; 20:4 n-6), induced a significant increase in medium fluorescence intensity (MFI) determined by fluorescence-activated cell sorting (FACS). The induction of PLP promoter was time-dependent showing maximal activity between 24 and 48 h after EPA exposure. PLP promoter activation was dependent on fatty acid concentration, with maximum activation at 200 microM. Northern blot analysis confirmed the fluorescence data in C6 cells incubated with EPA. Furthermore, this treatment increased the adenylyl cyclase-cyclic AMP (cAMP) levels and the mitogen-activated protein kinase (MAPK) activation in C6 cells. PLP promoter activity was inhibited by pre-treatment with H89 (protein kinase A (PKA) inhibitor), but not with PD98059 (MAPK inhibitor), suggesting that EPA stimulates the expression of PLP via cAMP-mediated pathways.
Salvati
Serafina
S
Department of Metabolism & Pathological Biochemistry, Istituto Superiore di Sanità, V le Regina Elena, Roma 299-00161, Italy. salvatis@iss.it
Natali
Francesco
F
Attorri
Lucilla
L
Raggi
Carla
C
Di Biase
Antonella
A
Sanchez
Massimo
M
D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D015152:Blotting, Northern; D015153:Blotting, Western; D001932:Brain Neoplasms / Q000378:metabolism*; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000096:biosynthesis; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015118:Eicosapentaenoic Acid; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis / Q000494:pharmacology*; D005910:Glioma / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D019787:Linoleic Acid / Q000378:metabolism; D008164:Luminescent Proteins / Q000096:biosynthesis / Q000235:genetics; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D018991:Myelin Proteolipid Protein / Q000096:biosynthesis* / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D013268:Stimulation, Chemical; D014162:Transfection; D017962:alpha-Linolenic Acid / Q000378:metabolism
D005231:Fatty Acids, Unsaturated; D008164:Luminescent Proteins; D018991:Myelin Proteolipid Protein; D012333:RNA, Messenger; D017962:alpha-Linolenic Acid; D049452:Green Fluorescent Proteins; D016718:Arachidonic Acid; D019787:Linoleic Acid; D015118:Eicosapentaenoic Acid; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D020928:Mitogen-Activated Protein Kinases