Insulin gene expression in immortalized rat hippocampal and pheochromocytoma-12 cell lines.
Employing reverse transcription-polymerase chain reaction and clonal cell lines derived by retroviral transduction of the temperature sensitive simian virus 40 large T-antigen into dispersed rat embryonic hippocampal cells, we detected the ancestral gene-insulin II mRNA in three progenitor subcloned cell lines. These cell lines upon differentiation are known to express markers indicative of commitment to either neuronal (H19-7; NF + , GFAP -), glial (H19-5; GFAP +, NF -), or bipotential (H583-5, NF +, GFAP + ) lineages. No duplicated, i.e., insulin I gene expression, was observed in any of the three cell lines. Induction of differentiation was associated with the persistence of insulin II mRNA and in the cells expressing a neuronal phenotype (H19-7; NF +, GFAP -) a relative doubling in insulin II mRNA level was present (P < 0.05). Minimal cellular insulin immunoreactivity was detected only in a subpopulation of cells with a differentiated neuronal phenotype. Radioimmunoassayable insulin peptide in the H19-7 cellular conditioned medium revealed a 5-fold increase in the differentiated state. In contrast, peripheral sympathetic PC-12 neuronal cells both in the undifferentiated and nerve growth factor-driven differentiated states, failed to express both insulin I and insulin II genes. We conclude that insulin II is expressed by cultured rat hippocampal clonal cell lines, and not by the peripheral sympathetic PC-12 neuronal cell line.
Singh
B S
BS
Department of Pediatrics, St. Louis University School of Medicine, Cardinal Glennon Children's Hospital, MO 63110, USA.
Rajakumar
P A
PA
Eves
E M
EM
Rosner
M R
MR
Wainer
B H
BH
Devaskar
S U
SU
D000818:Animals; D015139:Blotting, Southern; D002454:Cell Differentiation; D015870:Gene Expression; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism*; D007328:Insulin / Q000235:genetics*; D009474:Neurons / Q000378:metabolism*; D016716:PC12 Cells; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D011863:Radioimmunoassay; D051381:Rats
D007328:Insulin; D012333:RNA, Messenger