The effect of fibroblast growth factor on PC12 cells

Abstract

PC12 cells, which differentiate morphologically and biochemically into sympathetic neuron-like cells when treated with nerve growth factor, also respond to fibroblast growth factor. Some of the changes induced by fibroblast growth factor are similar to those seen after nerve growth factor treatment. Specifically, pituitary fibroblast growth factor causes the formation of processes initially comparable to those produced by nerve growth factor. However, in contrast to the outgrowth induced by nerve growth factor, which continues for several days, the outgrowth of processes induced by fibroblast growth factor ceases after about 3 days, even though fresh fibroblast growth factor is added. After about 6 days the processes induced by fibroblast growth factor have virtually disappeared. In this regard the processes induced by fibroblast growth factor are very similar to those induced by dibutyryl cyclic adenosine 3':5'-monophosphate (dBcAMP). The addition of nerve growth factor and fibroblast growth factor together appears to produce a synergistic effect on process formation, as does the simultaneous addition of nerve growth factor and dBcAMP. Cells pretreated (or primed) with nerve growth factor are able to regenerate processes much more rapidly in the presence of nerve growth factor than cells which have not been pretreated. When fibroblast growth factor is added to cells primed with nerve growth factor, more rapid regeneration of processes also occurs. The regeneration of neurites in response to either factor is blocked by the addition of an inhibitor of methylation. The process formation induced by fibroblast growth factor is preceded, as is the outgrowth in response to nerve growth factor treatment, by an induction of ornithine decarboxylase, a decrease in the phosphorylation of a specific cytoplasmic protein, and an increase in the phosphorylation of a specific non-histone nuclear protein. The effects of fibroblast growth factor and of nerve growth factor on ornithine decarboxylase are additive. Fibroblast growth factor does not cause an increase in the activity of acetylcholinesterase; nerve growth factor does. Fibroblast growth factor does not appear to be acting through the nerve growth factor receptor. The binding of iodinated nerve growth factor to PC12 cells is specific and is not inhibited by the presence of fibroblast growth factor. In addition, anti-nerve growth factor serum does not interfere with the action of fibroblast growth factor.(ABSTRACT TRUNCATED AT 400 WORDS)

Differentiation of PC12 cells in response to a cAMP analogue is accompanied by sustained activation of mitogen‐activated protein kinase

“…2b). In several experiments we have been unable to demonstrate neurite outgrowth in our PC12 cells in response to FGF (in contrast with Togari et al [18] and Rydel and Greene [20]). The cells do, however, respond to FGF as we see a small and transient activation of MAP kinase rather similar to that observed with insulin (S.W.Y., unpublished observations).…”

“…It was proposed on the basis of these results that a sustained activation of the MAP kinase cascade might be required for the differentiation of PC12 cells [15,16]. If such a phenomenon is central to the differentiation response then it should also apply to other agents which promote PC12 cell differentiation, including CAMP analogues such as dibutyryl cyclicAMP [18], interleukin 6 [19] and fibroblast growth factors [l&20]. As CAMP is well known to activate the CAMP-dependent protein kinase and had not previously been reported to regulate the activity of MAP kinase, we examined whether a more membrane permeant CAMP analogue, S-(4-chlorophenylthio)-cyclicAMP (CPT-CAMP) would promote PC12…”

Testing the in vivo role of protein kinase C and c-fos in neurite outgrowth by microinjection of antibodies into PC12 cells.

“…The rat pheochromocytoma cell line PC12 has been used widely to study neuronal differentiation (Greene and Tischler, 1982) and is a useful system in which to distinguish those intracellular signals that may be specific for inducing differentiation on the one hand from those that induce proliferation on the other. PC12 cells proliferate as round chromaffin-like cells when grown in standard culture conditions, but on addition of nerve growth factor (NGF) or basic fibroblast growth factor (bFGF), the cells stop dividing, extend numerous processes, and display characteristics of fully differentiated sympathetic neurons (Green and Tischler, 1982;Togari et al, 1985;Rydel and Green, 1987;Schubert et al, 1987 Technology, Pasadena, CA 91125. or src transforming proteins (Alema et al, 1985;BarSagi and Feramisco, 1985;Satoh et al, 1987;Eveleth et al, 1989;Rausch et al, 1989). Microinjection of antibodies that block the function of either the ras or the src proteins inhibits the induction of neurite outgrowth by NGF or by bFGF in both fused (Hagag et al, 1986) and native PC12 cells (Altin et al, 1991b), suggesting that these proteins are essential components of signal transduction pathways leading to differentiation in response to NGF and bFGF in PC12 cells.…”

Identification of the phosphorylation sites in elongation factor‐2 from rabbit reticulocytes

“…chain elongation. It is phosphorylated on threonine residues by a specific eEF-2 kinase, (previously termed Caa+/calmodulin.dependent protein kinase III [3,4]) and its phosphorylation is increased in intact ceils in response to stimuli which increase intracellular Ca z÷'ion concentrations [6][7][8][9][10][11][12][13]. Phosphorylation of the endogenous eEF-2 impairs the translation of mRNA in the reticulocyte lysate celt-free system [5] and several other lines of evidence show that phosphorylated eEF-2 is inactive, or has only low activity [3,4,14,15].…”