title: Regulation of rat brain/HepG2 glucose transporter gene expression by insulin and insulin-like growth factor-I in primary cultures of neuronal and glial cells.
abstract: We have demonstrated the expression of the rat brain/HepG2 glucose transporter gene in primary cultures of rat neuronal and glial cells by Northern blot analysis with a rat brain glucose transporter cDNA probe. Incubation of both neuronal and glial cells with insulin and insulin-like growth factor-I induced a time- and dose-dependent increase in the steady state levels of glucose transporter mRNA. The maximal response was achieved between 2-4 h and subsequently decreased. Both insulin and insulin-like growth factor-I at a dose of 1 ng/ml elicited an approximately 57% increase in glucose transporter mRNA levels in neuronal cultures after 90 min, suggesting that each peptide was acting through its own receptor. On the other hand, insulin stimulated [3H]2-deoxyglucose uptake in glial, but not neuronal, cells. These results suggest that insulin-like peptides regulate the expression of the rat brain/Hep G2 glucose transporter gene at both transcriptional and posttranscriptional levels, and that these regulatory mechanisms may be dissociated from each other. Insulin-like peptides may, therefore, participate in the control of brain energy metabolism.
authors.affiliation: Section on Molecular and Cellular Physiology, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland 20892.
authors.forename: H
authors.initials: H
authors.lastname: Werner
authors.forename: M K
authors.initials: MK
authors.lastname: Raizada
authors.forename: L M
authors.initials: LM
authors.lastname: Mudd
authors.forename: H L
authors.initials: HL
authors.lastname: Foyt
authors.forename: I A
authors.initials: IA
authors.lastname: Simpson
authors.forename: C T
authors.initials: CT
authors.lastname: Roberts
authors.forename: D
authors.initials: D
authors.lastname: LeRoith
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation / Q000187:drug effects*; D005947:Glucose / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology*; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D009004:Monosaccharide Transport Proteins / Q000235:genetics* / Q000378:metabolism; D009457:Neuroglia / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D013002:Somatomedins / Q000494:pharmacology*
chemical_list: D007328:Insulin; D009004:Monosaccharide Transport Proteins; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D005947:Glucose