Discordant Regulation of insulin-like growth factor-II and insulin-like growth factor binding protein-2 gene expression in a rat beta-cell line.
Expression and regulation of IGFBP-2 and IGF-II by GH and glucose in the rat insulin producing beta-cell line, INS-1, were determined. These cells express high levels of the insulin-like growth factor II (IGF-II) gene which is regulated by glucose. GH has no regulatory activities on IGF-II or IGFBP-2 gene expression. The levels of IGF-II and IGFBP-2 mRNA at increasing glucose concentrations are inversely regulated and exogenously added insulin inhibits IGFBP-2 gene expression at low glucose. These observations suggest that the expression of IGFBP-2 gene in this cell line is under the negative control of the endogenously produced insulin (and/or IGF-II) which accumulates to effective levels in the medium when the cells are cultured at high glucose concentrations.
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INSERM CJF-9313, Hôpital Robert Debré, Paris, France.
Czernichow
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Asfari
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D000818:Animals; D015152:Blotting, Northern; D002460:Cell Line; D015342:DNA Probes; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects*; D005947:Glucose / Q000494:pharmacology; D013006:Growth Hormone / Q000494:pharmacology; D007004:Hypoglycemic Agents / Q000494:pharmacology; D007328:Insulin / Q000494:pharmacology; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000096:biosynthesis* / Q000235:genetics; D007335:Insulin-Like Growth Factor II / Q000096:biosynthesis* / Q000235:genetics; D007515:Islets of Langerhans / Q000378:metabolism*; D007700:Kinetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000302:isolation & purification; D051381:Rats
D015342:DNA Probes; D007004:Hypoglycemic Agents; D007328:Insulin; D018971:Insulin-Like Growth Factor Binding Protein 2; D012333:RNA, Messenger; D007335:Insulin-Like Growth Factor II; D013006:Growth Hormone; D005947:Glucose