Neuronal PC12 cells induced by nerve growth factor (NGF) have been considered to be postmitotic and lack the ability to divide. However, in this study, we not only detected DNA synthesis but also observed cell division in some morphologically differentiated neuronal PC12 cells bearing long neurites. More interestingly, in addition to the division of perikaryon, the neurites located on the division site of the cell membrane also divided into two parts and were allocated to the two daughter cells. These results demonstrate that the morphologically differentiated neuronal PC12 cells still retain the ability to divide. This is the first report that neuronal PC12 cells as well as their neurites can divide.
Animals ; Cell Differentiation ; drug effects ; Cell Division ; drug effects ; DNA Replication ; drug effects ; physiology ; Nerve Growth Factor ; pharmacology ; Neurites ; drug effects ; Neurons ; cytology ; PC12 Cells ; Rats

Differentiation of neuronal cells has been shown to accelerate stress-induced cell death, but the underlying mechanisms are not completely understood. Here, we find that early and sustained increase in cytosolic ([Ca2+]c) and mitochondrial Ca2+ levels ([Ca2+]m) is essential for the increased sensitivity to staurosporine-induced cell death following neuronal differentiation in PC12 cells. Consistently, pretreatment of differentiated PC12 cells with the intracellular Ca2+-chelator EGTA-AM diminished staurosporine-induced PARP cleavage and cell death. Furthermore, Ca2+ overload and enhanced vulnerability to staurosporine in differentiated cells were prevented by Bcl-XL overexpression. Our data reveal a new regulatory role for differentiation-dependent alteration of Ca2+ signaling in cell death in response to staurosporine.
Animals ; Calcium/*metabolism ; Caspase 3/metabolism ; Cell Differentiation/*physiology ; DNA Fragmentation ; Mitochondria/metabolism ; *Neurons/cytology/drug effects/physiology ; *PC12 Cells/cytology/drug effects/physiology ; Rats ; Staurosporine/*pharmacology ; bcl-X Protein/metabolism