Jh. Taocheng et al., CHARACTERIZATION OF SYNAPTIC VESICLES AND RELATED NEURONAL FEATURES IN NERVE GROWTH-FACTOR AND RAS ONCOGENE DIFFERENTIATED PC12 CELLS, Journal of neuroscience research, 42(3), 1995, pp. 323-334
PC12 cells can differentiate into neuron-like cells after treatment wi
th either nerve growth factor (NGF) or transduction with a retrovirus
which expresses the K-ras oncogene, The concomitant treatment of NGF p
lus ras differentiates PC12 cells further than either agent alone with
respect to neurite outgrowth, acetylcholinesterase levels, and most s
trikingly, the number of synaptic vesicle (SV) clusters, These SV clus
ters in PC12 cell neurites closely resemble those in the presynaptic t
erminals of neurons, Such SV clusters have not been described in cell
lines previously. The SV clusters from all three differentiated groups
(NGF, ras, and NGF plus ras) were similar in size, shape, and configu
ration, except that the ones in the doubly treated group occur in high
er frequency and have more vesicles, The synaptic nature of these vesi
cle clusters was demonstrated by their regulated depletion after potas
sium stimulation, Furthermore, these vesicle clusters stained positive
ly for two SV-associated proteins, synapsin I and synaptophysin, by EM
immunocytochemistry (ICC), Such SV clusters in a cell line are very u
seful for characterizing the regulated release of SVs and the distribu
tion of SV-related antigens in intact cells, Analysis by SDS-gel elect
rophoresis and immunoblotting indicated that synapsin I levels are hig
her in all three differentiated groups compared to untreated cells; wh
ereas synaptophysin levels are lower in cells exposed to NGF alone or
with NGF and ras double treatment, Possible convergence and/or diverge
nce on the mechanisms of NGF and ras differentiation in PC12 cells are
discussed. (C) 1995 Wiiey-Liss, Inc.