NEUROPEPTIDE-Y GENE-EXPRESSION IN IMMORTALIZED RAT HIPPOCAMPAL AND PHEOCHROMOCYTOMA-12 CELL-LINES

Employing clonal cell lines derived from rat embryonic hippocampal cel ls, we detected neuropeptide Y (NPY) mRNA in three progenitor subclone d cell lines. These cell lines upon differentiation express markers in dicative of commitment to either neuronal (H19-7; NF +, GFAP -), glial (H19-5; GFAP +, NF -), or bipotential (H583-5; NF +, GFAP +) lineages . Induction of differentiation was associated with the persistence of the NPY mRNA, however, in the differentiated H19-7 cells a 20-fold inc rease in NPY mRNA levels was observed (P < 0.05). NPY immunoreactivity was observed only in cells with a differentiated neuronal phenotype. The cellular radioimmunoassayable NPY peptide levels increased twelve- fold without a change in extracellular NPY peptide levels by multi-fac torially induced neuronal or glial cell differentiation. The different iated H19-5 cells expressed lower levels of NPY that could not be immu nocytochemically detected. The peripheral sympathetic PC-12 neuronal c ells examined in the undifferentiated and nerve growth factor-driven d ifferentiated states expressed NPY only upon differentiation. We concl ude that NPY is expressed by the cultured undifferentiated and differe ntiated rat hippocampal clonal cell lines, while the peripheral sympat hetic PC-12 neuronal cell line only expresses the NPY gene upon differ entiation. These immortalized embryonic neural cell line(s) will provi de a hippocampal cell line(s) to conduct future in-vitro investigation s targeted at determining the cellular and molecular mechanisms govern ing NPY gene expression. (C) 1998 Elsevier Science B.V.