References

Notes: A single cell clonal line which responds reversibly to nerve growth factor (NGF) has been established from a rat adrenal pheochromocytoma. Thisline, designated PC12 , has a homogeneous and near-diploid chromosome number of 40. By 1 week `s exposure to NGF,the PC12 processes reach 500-1000 micro-m in length. Removal of NGF is followed by degeneration of processes within 24 hr and by resumption of cell multiplication within 72 hr. PC12cells grown with or without NGF contain dense core chromaffin-like granules up to 350 nm in diameter. The NGF-treated cells also contain small vesicles which accomolate on process varicosities and endings. PC12 cells synthesize and store the catecholamine neurotransmitters dopamine and norepinephrine. The levels (per mg of protesn) of catecholamines and of their synthetic emzymes if PC12cells are comparable to or higher than those found in rat adrenals. NGF-treatment of PC12 cells results in no change in the levels of catecholamines or of their synthetic enzymes when expressed of a per cell basis, but does result in a 4- to6- fole decrease in levels when expressed on a per mg of protein basis. PC12 cells do not synthesize epinephrine and cannot be induced to do so by treatment with dexamethasone. The PC12 cell line should be a useful model system for neurobiological and neurochmical studies.
Reference ID: 1110

Notes: We describe a cell-lineage marking system applicable to the vertebrate nervous system. The basis of the technique is gene transfer using the retroviral vector system. We used Escherichia coli bet-galactosidase as a marker gene and demonstrate a high level of expression of this marker from the viral long terminal repeat promoter, with simultaneous expression of the Tn5 neo gene from the simian virus 40 early promoter. This expression has allowed us to detect individual infected cells histochemically. We applied this marking technique to the study of lineage relationships in the developing vertebrate nervous system, both in vivo and histochemically identified clones of marked neural cells. In addition, wej used ttis virkus to infect cultures of rat cerebral cortex and have analyzed the clonal relationships of morphologicall different neural cell types.
Reference ID: 1506

Notes: Cellular extracts derived from pheochromocytoma cells (PC12-) inhibit the assembly of calf brain tubulin, while those derived from nerve growth factor-differentiated cells (PC12+) do not display this effect. Incubation with RNase abolishes the inhibition by PC12- extracts and reveals the presence of an activating effect exerted by PC12+ extracts. Activation of microtubule assembly is enhanced when extracts are prepared from PC12+ cells exposed for 1 day to 1.0 microM taxol and is abolished when PC12+ extracts are: (a) prepared from cells incubated for 1 day with 1 microM colchicine, (b) treated with the non-ionic detergent Nonidet P-40 or (c) centrifuged at 100 000 g instead of 80 000 g. 2D gel electrophoresis of the proteins of the 100 000 g pellet responsible for the activating effect (referred to as 100 K g pellet) reveals the presence of 100 K, 88 K and 32 K proteins which are markedly enriched in PC12+ extracts. The 88 K protein is further enriched in taxol-treated cells and markedly reduced in the same cells incubated with colchicine. A correlation between the differential protein composition of the 100 K g pellets and their effect on microtubule formation is postulated
Reference ID: 2475

Notes: Nerve growth factor (NGF) is essential for the development and differentiation of sympathetic or senxory neurons. A complementary DNA was cloned that corresponds to a gene sequence induced more than 50-fold in a cultured target cell line of pheochromocytoma cells (PC12 cells) 5 hours after the addition of NGF. The induced messenger RNA encodes a 90,000-dalton polypeptide that may represent one of the primary events in NGF-induced differentiation of neurons.
Reference ID: 1538

Notes: PC12 cells were cloned, and from their ability to form neurite-like processes 3 clones were selected: NGF-highly sensitive clone (HS), -moderately sensitive clone (MS), and -insensitive clone (IS). These clones were tested for the presence of specific NGF receptors by measuring the binding of 125-I-labeled NGF. All 3 clones were capable of binding NGF, but the HS clone had more NGF receptors than the MS and IS clones. The effects of methyl mercuric chloride (MMC) and/or nerve growth factor (NGF) on these clones were tested. The HS clone was a little more susceptible to MMC than the MS and IS clones. When NGF was added to the culture medium in addition to MMC, cell recovery was observed. The tendency toward recovery was more prominent in the HS clone than in the IS one. Recovery in the MS clone was intermediate. These results suggest that NGF treatment can contibute to functional recovery of PC12 cloned cells from the cytotoxic effects of MMC depending on their ability to react to NGF.
Reference ID: 4798