Stable transfection of cDNAs targeting specific steps of glycogen metabolism supports the existence of active gluconeogenesis in mouse cultured astrocytes

In order to assess the participation of astrocytic gluconeogenesis in the synthesis of glycogen, mouse astrocytes were stably transfected with antisense cDNA of fructose-1,6-bisphosphatase (FBPase) and with sense and antisense cDNAs of glycogen synthase (GS). The antisenses of FBPase and GS have similar significant effect in decreasing astrocyte glycogen content by 60%, while sense GS significantly increased glycogen content by 100%. The FBPase activity was decreased by all three cDNAs used, while glycogen phosphorylase was not altered. The activity of GS was decreased by the antisense GS and increased by the sense GS. These data demonstrate that the gluconeogenesis in astrocytes is involved in the glycogenesis modulation.